No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The Effects of Chronic Betaine Supplementation on Exercise Performance, Skeletal Muscle Oxygen Saturation and Associated Biochemical Parameters in Resistance Trained Men
Abstract
We examined the effects of chronic betaine supplementation on exercise performance and associated parameters in resistance trained men. Men were randomly assigned in a double-blind manner using a crossover design to consume betaine (2.5 g of betaine mixed in 500 ml of Gatorade®) or a placebo (500 ml of Gatorade®) for 14 days, with a 21-day washout period. Before and after each treatment period, tests of lower- and upper-body muscular power and isometric force were conducted, including a test of upper-body muscular endurance (10 sets of bench press exercise to failure). Muscle tissue oxygen saturation (StO 2) during the bench press protocol was measured via near infrared spectroscopy. Blood samples were collected before and after the exercise test protocol for analysis of lactate, nitrate/nitrite (NOx), and malondialdehyde (MDA). When analyzed using a repeated measures analysis of variance, no significant differences were noted between conditions for exercise performance variables (p > 0.05). However, an increase in total repetitions (p = 0.01) and total volume load (p = 0.02) in the 10-set bench press protocol was noted with betaine supplementation (paired t-tests), with values increasing approximately 6.5% from preintervention to postintervention. Although not of statistical significance (p = 0.14), postexercise blood lactate increased to a lesser extent with betaine supplementation (210%) compared with placebo administration (270%). NOx was lower postintervention as compared with preintervention (p = 0.06), and MDA was relatively unchanged. The decrease in StO 2 during the bench press protocol was greater with betaine vs. placebo (p = 0.01), possibly suggesting enhanced muscle oxygen consumption. These findings indicate that betaine supplementation results in a moderate increase in total repetitions and volume load in the bench press exercise, without favorably impacting other performance measures.
... Out of the 23 remaining studies, 6 did not meet the specified inclusion criteria (two studies used acute betaine supplementation) (Armstrong et al., 2008;Dantas et al., 2021) three studies used multi-ingredient supplementation (Kraemer et al., 2007;Schwarz et al., 2019;William Kedia et al., 2014) and no exercise test was performed in the other one (Willingham, 2021). Consequently, 17 studies aligned with the inclusion criteria and were incorporated into the systematic review (Apicella, 2011;Arazi et al., 2022;Cholewa et al., 2013Cholewa et al., , 2018Del Favero et al., 2012;Hoffman et al., 2009Hoffman et al., , 2011Lee et al., 2010;Moro et al., 2020;Pryor et al., 2012;Trepanowski et al., 2011;Waldman et al., 2023;Yang et al., 2020Yang et al., , 2022Zawieja et al., 2023). The process of final study selection is depicted in the PRISMA flow diagram (Figure 1). ...
... Included studies used a variety of exercise performance tests. VJ was measured in eight studies (Cholewa et al., 2013(Cholewa et al., , 2018Hoffman et al., 2009;Lee et al., 2010;Trepanowski et al., 2011;Yang et al., 2022); one repetition maximum (1RM) in BP in 5 studies (Cholewa et al., 2013(Cholewa et al., , 2018Del Favero et al., 2012;Yang et al., 2022); 1RM in squat (SQ) in 4 studies (Cholewa et al., 2013(Cholewa et al., , 2018Del Favero et al., 2012;Yang et al., 2022); BP endurance in four studies (Arazi et al., 2022;Hoffman et al., 2009;Lee et al., 2010;Trepanowski et al., 2011); and cycling sprints in four studies (Hoffman et al., 2009;Pryor et al., 2012;Waldman et al., 2023;Zawieja et al., 2023); isometric BP (Apicella, 2011;Lee et al., 2010;Trepanowski et al., 2011); and BP throw (Hoffman et al., 2009;Lee et al., 2010;Trepanowski et al., 2011) in 3 studies each; 1RM in leg press (LP) ; isometric SQ (Apicella, 2011;Lee et al., 2010); LP endurance (Arazi et al., 2022;; SQ endurance (Hoffman et al., 2009;Lee et al., 2010) in 2 studies each. The remaining performance tests were used in only one study each (power output in 6 rep x 60% 1RM in BP and SQ) (Del Favero et al., 2012) isokinetic peak concentric (CON) and eccentric (ECC) force in chest press (Hoffman et al., 2011) isokinetic muscle endurance in chest press 5 sets x 6 reps x 80% of peak CON and ECC force (Hoffman et al., 2011) 3 reps SQ jump (Lee et al., 2010) 3RM in SQ, 2 km rowing, Bergeron beep test (Moro et al., 2020) change of direction, 10 m sprint, 30 m sprint, repeated sprints, 30-15 intermittent fitness test (for VO 2 max) isometric force in LP (Trepanowski et al., 2011) graded exercise test (Waldman et al., 2023) exhaustive endurance exercise (Yang et al., 2020) overhead Medicine-Ball Throw Test, 1RM in overhead press, sumo deadlift and Fight Gone Bad (Zawieja et al., 2023). ...
... Included studies used a variety of exercise performance tests. VJ was measured in eight studies (Cholewa et al., 2013(Cholewa et al., , 2018Hoffman et al., 2009;Lee et al., 2010;Trepanowski et al., 2011;Yang et al., 2022); one repetition maximum (1RM) in BP in 5 studies (Cholewa et al., 2013(Cholewa et al., , 2018Del Favero et al., 2012;Yang et al., 2022); 1RM in squat (SQ) in 4 studies (Cholewa et al., 2013(Cholewa et al., , 2018Del Favero et al., 2012;Yang et al., 2022); BP endurance in four studies (Arazi et al., 2022;Hoffman et al., 2009;Lee et al., 2010;Trepanowski et al., 2011); and cycling sprints in four studies (Hoffman et al., 2009;Pryor et al., 2012;Waldman et al., 2023;Zawieja et al., 2023); isometric BP (Apicella, 2011;Lee et al., 2010;Trepanowski et al., 2011); and BP throw (Hoffman et al., 2009;Lee et al., 2010;Trepanowski et al., 2011) in 3 studies each; 1RM in leg press (LP) ; isometric SQ (Apicella, 2011;Lee et al., 2010); LP endurance (Arazi et al., 2022;; SQ endurance (Hoffman et al., 2009;Lee et al., 2010) in 2 studies each. The remaining performance tests were used in only one study each (power output in 6 rep x 60% 1RM in BP and SQ) (Del Favero et al., 2012) isokinetic peak concentric (CON) and eccentric (ECC) force in chest press (Hoffman et al., 2011) isokinetic muscle endurance in chest press 5 sets x 6 reps x 80% of peak CON and ECC force (Hoffman et al., 2011) 3 reps SQ jump (Lee et al., 2010) 3RM in SQ, 2 km rowing, Bergeron beep test (Moro et al., 2020) change of direction, 10 m sprint, 30 m sprint, repeated sprints, 30-15 intermittent fitness test (for VO 2 max) isometric force in LP (Trepanowski et al., 2011) graded exercise test (Waldman et al., 2023) exhaustive endurance exercise (Yang et al., 2020) overhead Medicine-Ball Throw Test, 1RM in overhead press, sumo deadlift and Fight Gone Bad (Zawieja et al., 2023). ...
Betaine supplementation, a dietary practice that possesses potential effects on exercise performance, has undergone extensive study. This study aimed to systematically review and meta-analyse betaine supple-mentation's effects on exercise performance. We searched PubMed, Web of Science, Scopus, and Google Scholar, focusing on studies comparing chronic betaine to a placebo in healthy humans aged 15-60 years, measuring exercise outcomes. Studies with acute betaine supplementation, no control group, or animals were excluded. Quality assessment was done using the Cochrane Risk of Bias Tool, and a random-effects model was employed for the meta-analysis. The review included 17 studies with 317 participants (21% female). The results revealed a significant effect size of 0.47 (95% CI 0.04 to 0.89) for maximal strength (1RM, 3RM, maximal isokinetic or isometric force), particularly in the lower body (SMD: 0.49, 95% CI 0.01 to 0.98). No significant effects were found for upper body strength, cycling sprint power, bench press throws power, or muscular endurance. However, vertical jumping performance improved significantly (SMD: 0.36, 95% CI 0.03 to 0.69) after excluding a low-quality study. In conclusion, betaine supplementation for at least 7 days significantly enhances muscular strength, especially lower body strength, and shows potential in improving vertical jumping performance. ARTICLE HISTORY
... Therefore, betaine supplementation may have ergogenic effects on muscular performance of strength and power via maintaining cell completeness, increasing creatine level, and positive responses of the metabolic hormones. Previous human studies provided 1.25 g of betaine mixed in 240-300 mL of sports drink twice per day for 7 consecutive days [24], 10 days [25], or 14-15 days [17,18,26,27] to investigate the effects of betaine supplementation on exercise performance. Some studies reported that betaine supplementation would not enhance exercise performance [25][26][27]. ...
... Previous human studies provided 1.25 g of betaine mixed in 240-300 mL of sports drink twice per day for 7 consecutive days [24], 10 days [25], or 14-15 days [17,18,26,27] to investigate the effects of betaine supplementation on exercise performance. Some studies reported that betaine supplementation would not enhance exercise performance [25][26][27]. Moreover, the participants in those studies are untrained or recreationally trained individuals [17,18,[24][25][26][27][28][29]. ...
... Some studies reported that betaine supplementation would not enhance exercise performance [25][26][27]. Moreover, the participants in those studies are untrained or recreationally trained individuals [17,18,[24][25][26][27][28][29]. Previous studies reported that 2 g/day for 10 days and 2.5 g/day for 14 days of betaine supplementation does not affect strength or power performance in untrained subjects [25,27]. ...
Simple Summary
Betaine supplementation has ergogenic potential for exercise performance, but the effect of betaine supplementation in combination with training for 6 weeks is still unclear. The present study aimed to investigate the effects of betaine supplementation on muscular power and maximal strength in collegiate male athletes. The participants in the study received either 5 g/day of betaine or placebo for 6 weeks, during which they maintained their regular exercise training. The overhead medicine-ball throw, countermovement jump, and one repetition-maximum of a bench press, overhead press, half squat, and sumo dead lift by the participants were assessed before and after betaine supplementation. Blood lipids were also analyzed before and after betaine supplementation. We found that receiving 5 g of betaine supplementation daily during the 6-week preparatory period had extra benefits on the power of the upper body and maximal strength on the half squat and overhead press. Betaine seems to be a useful nutritional strategy to improve and maintain performance during 6-week preparatory periods in collegiate athletes.
Abstract
The purpose of this study was to investigate the effects of 6-week betaine supplementation during a preparatory period of collegiate athletes on muscular power and strength. Sixteen male collegiate athletes received 5 g/day of betaine (betaine group, n = 9) or carboxymethyl cellulose (placebo group, n = 7) for 6 weeks. All participants engaged in their regular training during the experimental period. The overhead medicine-ball throw (OMBT), countermovement jump, and maximal strength (one repetition maximum, 1-RM) on the bench press, overhead press, half squat, and sumo dead lift by the participants were assessed before and after betaine supplementation. Blood lipids were also analyzed before and after betaine supplementation. After supplementation, there were no significant differences between betaine and placebo groups on any variables. Compared to presupplementation, the performance of OMBT and 1-RM of overhead press and half squat in the betaine group had significantly improved (p < 0.05). By contrast, no significant differences were observed in the placebo group before and after supplementation. Blood analysis revealed no negative effect on blood lipid profiles. Betaine seems to be a useful nutritional strategy to improve and maintain performance during 6-week preparatory periods in collegiate athletes.
... Subsequently, other investigators examined performance benefits from sub-chronic (2 weeks) betaine supplementation in RE. The results of these studies provide equivocal evidence, with some reporting improvements in strength and power [12,13], and others reporting no improvements in these performance parameters [8,14,15]. Nevertheless, it has been suggested that betaine may have a potential ergogenic effect in RE protocols with high metabolic stress [2]. For example, Hoffman et al. [8] showed that 15 days of betaine supplementation (2.5 g/day) improved squat exercise repetitions to fatigue with 75% of 1RM, without similar improvement in the bench press performance. ...
... In this trial, participants also completed more repetitions at or above 90% power output. In support of these results, reductions in muscle fatigue [16] and increases in bench press total volume (~6.5%) and repetitions to fatigue [15] have been reported after a sub-chronic period (i.e. 14-15 days) of betaine ingestion. ...
... To date, the small body of research involving betaine and RE has focused primarily on performance factors (i.e. strength, power, endurance) [8,14,16,17,13], with very little attention given to indices of endocrine function [6,12,15]. Furthermore, the effect of betaine and RE in adolescent athletes is unknown. Preliminary research has shown that betaine supplementation at 2.5 to 3 g/day for 14 days in trained men led to a non-significant change in blood lactate [15], and a significant increase in growth hormone (GH) and IGF-1 [6,12] in response to acute bouts of RE. ...
Objective:
This study examined the effects of short-term betaine supplementation on muscle endurance, plasma lactate, testosterone and cortisol levels, and the testosterone to cortisol (T/C) ratio in response to acute resistance exercise (RE).
Method:
Using a double-blind, crossover study design, 10 handball players (age ± SD = 16 ± 1 yrs) without prior-structured RE experience performed a high-intensity RE session (leg press followed by bench press; 5 sets to volitional fatigue using 80% baseline 1 repetition maximum (1RM)), before and after 14 days of either placebo (maltodextrin) or betaine (2.5 g·d-1) supplementation. A 30-day washout period separated each treatment. 48 h prior to testing sessions, participants recorded their food intake and did not perform strenuous exercise. Venous blood was sampled before supplementation, and before and after each RE session.
Results:
After betaine supplementation, participants performed more repetitions (p < 0.001) during the leg press (Betaine: 35.8 ± 4.3; Placebo: 24.8 ± 3.6, Cohen's d = 2.77) and bench press (Betaine: 36.3 ± 2.6; Placebo: 26.1 ± 3.5, Cohen's d = 3.34). Betaine resulted in lower post-exercise cortisol (Betaine: 7.6 ± 1.7; Placebo: 13 ± 3.4 µg.dL-1, p = 0.003, generalized eta squared ( η G 2 ) = 0.49) and lactate (Betaine: 5.2 ± 0.3; Placebo: 6 ± 0.3 mmol.L-1, p < 0.001, η G 2 = 0.96) and higher total testosterone (Betaine: 15.2 ± 2.2; Placebo: 8.7 ± 1.7 ng.mL-1, p < 0.001, η G 2 = 0.87) and T/C ratio (Betaine: 0.21 ± 0.05; Placebo: 0.07 ± 0.02, p < 0.001, = 0.82).
Conclusions:
Two weeks of betaine supplementation improved upper- and lower-body muscle endurance and influenced indices of endocrine function following an acute session of high-intensity RE in adolescent handball players.
... Nevertheless, urinary excretion is low (;4%) and is primarily in the form of betaine's metabolic byproduct, dimethylglycine (78). Although other compounds exist, most research settings use betaine anhydrous either in isolation or in combination with a carbohydrate sports drink (4,13,40,87). ...
... Previous authors have noted that betaine preferentially potentiates performance in the upper extremities; however, current evidence suggests no such trend (11). Varying indices of strength, specifically related to muscular endurance, seem to occur in both the upper and lower body, but the origin of this discrepancy is unclear (30, 87). Betaine supplementation in the realm of performance is both recent Strength and Conditioning Journal | www.nsca-scj.com ...
... Betaine Supplementation Targeting Human Performance and/or Body Composition(12,13,30,40,56,66,67,87) Strength and Conditioning Journal | www.nsca-scj.com ...
Blood flow restriction (BFR) training and betaine supplementation are emerging training tools with growing evidence, potentially providing a synergistic stimulus to augment skeletal muscle adaptation. Betaine may facilitate stretch-mediated anabolism secondary to BFR-induced extracellular-to-intracellular fluid influx, whereby their combination may promote a new, low-barrier avenue for athletes and clinical practitioners to elicit hypertrophy and strength. This review aims to (a) demonstrate existing evidence on BFR- and betaine-mediated skeletal muscle growth, (b) provide rationale for their combination as a superior anabolic stimulus, and (c) advocate for athletes and the elderly as prime demographics for a potentially valuable BFR-betaine synergistic therapy.
... Betaine has been shown to defend citrate synthase against thermodenaturation and therefore may have increased aerobic energy production via improved Krebs cycle function [26]. In support of this hypothesis, Trepanowski et al. [27] reported that 14 days of betaine treatment resulted in a greater average exercise muscle tissue oxygen saturation (StO 2 ) difference after high-volume bench press exercise. ...
... ↔ Back squat or bench power, 1RM, or muscle creation content Trepanowski et al. [27] Resistance-trained men (N = 13) 2.5 g of betaine mixed in 500 mL of Gatorade or a placebo (500 mL of Gatorade) for 14 days, with a 21-day washout period. Muscular power and isometric force and upper-body muscular endurance (10 sets of bench press exercise to failure) were assessed. ...
... Trepanowski et al. [27] then investigated the effects of 15 days of 2.5 g/day of betaine supplementation on strength, power, and strength-endurance performance in 13 recreationally resistance-trained males using a double-blind, crossover design. Subjects were tested at baseline and after 15 days of treatment ingestion by the following tests: the best of three vertical jump attempts, the best of three bench press throw attempts, maximal isometric leg press force, maximal isometric bench press force, and 10 sets to volitional fatigue of 50% 1RM Hammer Strength bench press. ...
... The applicant provided a number of human studies on betaine. Several studies in healthy subjects investigated the effect of betaine on plasma homocysteine concentrations (Brouwer et al., 2000;Olthof et al., 2003) or on physical exercise (Armstrong et al., 2008;Hoffman et al., 2009;Lee et al., 2010a;Trepanowski et al., 2011;del Favero et al., 2012;Pryor et al., 2012) at a single dose of 5 g/day (Armstrong et al., 2008), doses up to 2.5 g/day for periods up to 15 days (Hoffman et al., 2009;Lee et al., 2010a;Trepanowski et al., 2011;del Favero et al., 2012;Pryor et al., 2012) or at 6 g/day for 6 weeks (Brouwer et al., 2000;Olthof et al., 2003). These studies did not investigate safety-related endpoints, although one short-period study, in which 13 men received 2.5 g of betaine for 14 days, reported that no adverse effects were noted with either betaine or placebo supplementation and that treatment with betaine was well tolerated (Trepanowski et al., 2011). ...
... The applicant provided a number of human studies on betaine. Several studies in healthy subjects investigated the effect of betaine on plasma homocysteine concentrations (Brouwer et al., 2000;Olthof et al., 2003) or on physical exercise (Armstrong et al., 2008;Hoffman et al., 2009;Lee et al., 2010a;Trepanowski et al., 2011;del Favero et al., 2012;Pryor et al., 2012) at a single dose of 5 g/day (Armstrong et al., 2008), doses up to 2.5 g/day for periods up to 15 days (Hoffman et al., 2009;Lee et al., 2010a;Trepanowski et al., 2011;del Favero et al., 2012;Pryor et al., 2012) or at 6 g/day for 6 weeks (Brouwer et al., 2000;Olthof et al., 2003). These studies did not investigate safety-related endpoints, although one short-period study, in which 13 men received 2.5 g of betaine for 14 days, reported that no adverse effects were noted with either betaine or placebo supplementation and that treatment with betaine was well tolerated (Trepanowski et al., 2011). ...
... Several studies in healthy subjects investigated the effect of betaine on plasma homocysteine concentrations (Brouwer et al., 2000;Olthof et al., 2003) or on physical exercise (Armstrong et al., 2008;Hoffman et al., 2009;Lee et al., 2010a;Trepanowski et al., 2011;del Favero et al., 2012;Pryor et al., 2012) at a single dose of 5 g/day (Armstrong et al., 2008), doses up to 2.5 g/day for periods up to 15 days (Hoffman et al., 2009;Lee et al., 2010a;Trepanowski et al., 2011;del Favero et al., 2012;Pryor et al., 2012) or at 6 g/day for 6 weeks (Brouwer et al., 2000;Olthof et al., 2003). These studies did not investigate safety-related endpoints, although one short-period study, in which 13 men received 2.5 g of betaine for 14 days, reported that no adverse effects were noted with either betaine or placebo supplementation and that treatment with betaine was well tolerated (Trepanowski et al., 2011). ...
Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on betaine as a novel food (NF) pursuant to Regulation (EC) No 258/97. The information provided on the composition, the specifications, the batch-to-batch variability, stability and production process of the NF is sufficient and does not raise concerns about the safety of the NF. The NF is proposed to be used in foods intended to meet additional requirements for intense muscular effort with a maximum intake of 2.5 g/day of betaine for sports people above 10 years of age. Based on the lowest BMDL05, which was derived from a chronic toxicity study in rats in which a dose-related increase in platelet counts was observed, and the anticipated daily intake of the NF in the target population, the Margins of Exposure are 3.6 and 5, which are generally regarded as not sufficient. However, the total exposure to betaine from the diet (about 830 mg/day) is not known to be associated with adverse effects. Moreover, no adverse effects on platelet counts were noted in human intervention studies with exposure levels of 4 g/day of betaine for up to 6 months. A significant increase in total and low-density lipoprotein (LDL)-cholesterol concentrations was noted at intakes of 4 g/day of betaine in overweight subjects with metabolic syndrome but not in healthy subjects, nor at intakes of 3 g/day. Thus, considering 4 g/day of betaine as a reference point and applying an uncertainty factor of 10 to account for interindividual variability, an amount of 400 mg/day of betaine (i.e. 6 mg/kg body weight (bw) per day for adults) in addition to the background exposure is considered as safe. The Panel considers that the NF is safe to be used at maximum intake of 6 mg/kg bw per day in the target population.
... In addition, 2.5 g is a dosage that has been shown to significantly elevate plasma BET levels and is therefore a scientifically an appropriate level of supplementation (33). In 4 of the studies, (18,23,30,35) the supplement was administered twice daily, 1.25 g each time. However, in 1 study (17) the supplement was given as a single 2.5 g dosage of BET. ...
... To measure power, studies used vertical jump (VJ) tests (7,18,35), bench press throw (BPT) (18,23,35), bench press (BP) and back squat (BS) power output (13), Wingate anaerobic power tests (WAnT) (18), and sprint tests using an ergometer (30). Bench press throw has been recommended as the exercise for the most accurate assessment of upperbody power (16). ...
... To measure power, studies used vertical jump (VJ) tests (7,18,35), bench press throw (BPT) (18,23,35), bench press (BP) and back squat (BS) power output (13), Wingate anaerobic power tests (WAnT) (18), and sprint tests using an ergometer (30). Bench press throw has been recommended as the exercise for the most accurate assessment of upperbody power (16). ...
Betaine has recently gotten much attention for its potential role as an ergogenic aid and has become a common ingredient in peri-workout dietary supplements. The purpose of this systematic review of the literature was to investigate the effects of betaine supplementation on muscular strength and power. A computerized literature search of 3 databases (PubMed, MEDLINE, and Scopus) was performed. Included in the review were randomized controlled trials that measured muscle strength, power, and/or endurance in healthy participants. Quality was assessed using the PEDro scale. Seven trials were identified, and quality assessment showed all were of 'excellent quality.' Only two of the studies reported increases in strength and/or power after supplementation with BET. The remaining five studies showed no change in any strength or power outcome measures with BET supplementation. This review highlights the lack of evidence for a clear ergogenic effect of BET supplementation on strength and power performance. However, since two studies did identify increases of up to 24.61% on strength and power as a result of BET supplementation, additional studies are necessary to evaluate its effectiveness.
... Enhancing performance in the canine athlete through dietary measures has been constantly sought as some supplements have shown modest performance enhancement in rodents and human subjects (4)(5)(6)(7) . A number of studies involving sled dogs and racing Greyhounds have been published showing that dietary supplements enriched with antioxidants such as vitamins E, C and β-carotene fail to ameliorate rises in creatine kinase (CK) as a marker of muscle permeability changes (8)(9)(10) . ...
... Antioxidants, such as vitamins E and C may, in fact, have detrimental effects on performance in racing Greyhounds (12,13) . Although these vitamins and antioxidants have not proven particularly useful, the effects of compounds such as betaine during physical heat stress and resveratrol for improved mitochondrial function in rodents and human subjects hold promise (4)(5)(6)(7) . ...
... When examining the constituents in the premix, studies have shown increased antioxidant capacity in serum or tissue; however, they have never been shown to alter muscle metabolism, energetics or permeability as measured by alterations in CK. Betaine has been shown to improve intracellular pH and osmolality and has been correlated to improved heat tolerance in agricultural animals and exercise performance in human athletes (5,6) . Betaine is traditionally used as a choline substitute in animal feeds, but has not been evaluated as a performance enhancing supplement for dogs. ...
Enhancing performance through dietary measures is constantly sought as some supplements have shown modest performance enhancement in rodents and human subjects. To evaluate a proprietary dietary supplement, a study was undertaken to assess the effect of diet and exercise on blood physiological parameters during a tracking American Fox Hound field championship. Ten dogs were assigned to two different groups. Group A received a commercial kibble and Group B received the same diet with the addition of a supplement added to the dietary premix for 4 weeks before the field event. Blood was collected at rest, immediately following days 1 and 2 of the event and 48 h after day 2. Blood chemistry, complete blood cell counts and cortisol concentrations were analysed. Competition performance was also documented for all dogs using a points system for tracking events. Many chemistry parameters and blood cell counts changed significantly due to exercise. Differences between the dietary groups showed that Group B had significantly lower aspartate aminotransferase on days 1 and 2 of exercise and lower creatine kinase on day 2. Based on tracking scores, dogs in Group B out-performed dogs in Group A. This study suggests that endurance hunting dogs develop changes in serum markers of musculoskeletal integrity that might be mitigated by the addition of the supplement, resulting in better performance. Although intriguing, follow-up controlled studies are needed to ensure that the enhanced performance was not biased due to lack of randomisation.
... BET is endogenously produced during times of stress (i.e., dehydration or hypertonic state during exercise) to protect the cell. BET does this through maintenance of cellular hydration, which enhances muscle cell survival and protein synthesis (41,78,81). Ultimately, these properties of BET may help to protect muscle tissue from exerciseinduced damage. ...
... However, direct enhancement of these mechanisms with BET supplementation has not thoroughly been examined. Trepanowski et al. reported significantly higher squat repetitions and lifting volume but no effects on muscular strength or power with 2.5 g/d of BET for 2 weeks in resistance-trained young men (78). However, these results were not a consequence of increased protein metabolism; rather, the authors reported that changes were likely due to an increase in oxygen saturation and an attenuation of blood lactate levels (78 Therefore, there may be a higher propensity of power improvements in untrained individuals, likely mediated by improved oxygen saturation and lactate levels. ...
... Trepanowski et al. reported significantly higher squat repetitions and lifting volume but no effects on muscular strength or power with 2.5 g/d of BET for 2 weeks in resistance-trained young men (78). However, these results were not a consequence of increased protein metabolism; rather, the authors reported that changes were likely due to an increase in oxygen saturation and an attenuation of blood lactate levels (78 Therefore, there may be a higher propensity of power improvements in untrained individuals, likely mediated by improved oxygen saturation and lactate levels. ...
THIS REVIEW SUMMARIZES THE EMPIRICAL RESEARCH OF THE EFFECTIVENESS, SAFETY, AND DOSAGES OF THE LESSER-KNOWN, BUT COMMONLY ADDED, SUPPORTIVE INGREDIENTS IN MULTI-INGREDIENT PERFORMANCE SUPPLEMENTS (MIPS). PRIMARY INGREDIENTS THAT ARE WELL KNOWN AND PREVIOUSLY REVIEWED (I.E., CAFFEINE, CREATINE, BETA-ALANINE) ARE EXCLUDED FROM THIS REVIEW. THE IMPROVEMENTS REPORTED ARE COMMONLY MEDIATED BY SECONDARY MECHANISMS SUCH AS IMPROVED BLOOD FLOW, PROTEIN BALANCE, METABOLISM, AND ANTIOXIDANT STATUS. OVERWHELMING EVIDENCE EXISTS SUGGESTING THAT THE SUPPORTIVE INGREDIENTS IN MIPS ARE SAFE TO USE; HOWEVER, THE AMOUNT PRESENT IN MOST MIPS IS LIKELY TOO SMALL TO ELICIT STRENGTH, POWER, OR RECOVERY RESPONSES.
... The increased VO2 consumption during the final sprint in the betaine group may have been attributed to increased protein stability and muscle oxygen consumption. Trepanowski et al. (2011) demonstrated 14 days of betaine ingestion resulted in greater post-exercise muscle tissue oxygen saturations compared to placebo. Betaine has been shown to defend citrate synthase against thermodenaturation, and thereby may have enhanced Kreb's cycle efficiency (Caldas et al. 1999). ...
... Our group demonstrated that betaine supplementation improved bench press work capacity during cycles of high (2 weeks, each of 3 sets of 8-10 and 12-15 repetitions, respectively), but not low (4 sets of 4-6 repetitions) volume training (Cholewa et al. 2013). The discrepancy in findings may have been due to the sets and intensity prescribed: betaine improved work capacity when multiple sets to fatigue with \75 % 1 RM were prescribed (Cholewa et al. 2013;Trepanowski et al. 2011), whereas no improvements were seen with 1 and 3 sets to fatigue at 75 and 85 % 1 RM, respectively (Hoffman et al. 2009;Lee et al. 2010). Betaine may, therefore, pose the most ergogenic potential in exercise protocols generating high levels of metabolic stress, such as those employing shorter rest periods and higher volumes. ...
... The mechanisms of action whereby betaine improves performance have also yet to be identified. Due to the increases in power and force production during short duration exercises requiring high rates of phosphagen metabolism and because dietary betaine supplementation increases serum SAM availability in healthy men (Craig 2004), several researchers have suggested betaine may improve performance via enhanced creatine synthesis (Fig. 1, Hoffman Lee et al. 2010;Trepanowski et al. 2011). Betaine supplementation increases muscle PCr in animals (Wise et al. 1997); however, 10 days of 2 g/day betaine supplementation did not enhance muscle PCr content in humans (Del Favero et al. 2011). ...
Betaine is a methyl derivative of glycine first isolated from sugar beets. Betaine consumed from food sources and through dietary supplements presents similar bioavailability and is metabolized to di-methylglycine and sarcosine in the liver. The ergogenic and clinical effects of betaine have been investigated with doses ranging from 500 to 9,000 mg/day. Some studies using animal models and human subjects suggest that betaine supplementation could promote adiposity reductions and/or lean mass gains. Moreover, previous investigations report positive effects of betaine on sports performance in both endurance- and resistance-type exercise, despite some conflicting results. The mechanisms underlying these effects are poorly understood, but could involve the stimulation of lipolysis and inhibition of lipogenesis via gene expression and subsequent activity of lipolytic-/lipogenic-related proteins, stimulation of autocrine/endocrine IGF-1 release and insulin receptor signaling pathways, stimulation of growth hormone secretion, increased creatine synthesis, increases in protein synthesis via intracellular hyper-hydration, as well as exerting psychological effects such as attenuating sensations of fatigue. However, the exact mechanisms behind betaine action and the long-term effects of supplementation on humans remain to be elucidated. This review aims to describe evidence for the use of betaine as an ergogenic and esthetic aid, and discuss the potential mechanisms underlying these effects.
... Betaine (trimethylglycine) is an organic osmolyte found in many foods, including spinach, beets, and whole grains [1]. Administration of supplemental betaine for 10–15 days has enhanced performance in several studies but with varying results: Lee et al. [2] reported increased power output and force production, whereas others [3,4] reported improvements in muscular endurance but not power. On the other hand, Del Favero et al. [5] reported no improvements in power output, strength, or body composition with 10 days of betaine treatment; however, subjects were instructed to avoid training and supplementation was ceased 5 days prior to performance testing. ...
... The improvements in bench press work capacity differ from previous studies where betaine did not improve single-set repetitions to fatigue at 75% [3] or 3 sets of repetitions to fatigue at 85% 1 RM [2] . In contrast, betaine improved work capacity for 10 sets of repetitions to fatigue at 50% 1 RM [4]. Given improved work capacity with higher volume resistance training prescriptions, and the lack of improvement during micro-cycle 2 which imposed less of a metabolic demand (4 sets of 4–6Figure 3 Bar graph for arm cross sectional area (cm 2 ) for placebo (n = 12) and betaine (n = 11) for pre-and post-treatment. ...
... The improvements in work capacity at micro-cycle three but not micro-cycle one or two also contradict our hypothesis that betaine may be most ergogenic when combined with exercise protocols producing higher levels of metabolic stress. Given the improvement in bench press work capacity that also occurred at micro-cycle three but not two, and the lack of improvement with only 2 weeks of sup- plementation [2,4], it may also be that the effects of increased intramuscular betaine manifest over a longer period of time, and therefore require at least a 4–6 week ingestion period. There were no differences between groups for back squat 1 RM improvements, and despite increases in bench press training volume with betaine, bench press 1 RM did not improve. ...
This study investigated the effects of long term betaine supplementation on body composition, performance, and homocysteine thiolactone (HCTL) in experienced strength trained men.
Twenty-three subjects were matched for training experience (4.8 +/- 2.3 years) and body fat percentage (BF%: 16.9 +/- 8.0%), randomly assigned to either a placebo (PL; n = 12) or betaine group (BET; n = 11; 2.5 g/day), and completed a 6 week periodized training program consisting of 3 two-week micro-cycles. Bench press and back squat training volumes were recorded and changes in training volume were assessed at each micro-cycle. Fasting urine was collected at baseline (BL), weeks 2, 4 and 6, and assayed for HCTL. Subjects were tested prior to and following 6 weeks of treatment. Arm and thigh cross sectional area (CSA) was estimated via girth and skin fold measurements. Body density was estimated via skin fold calipers and used to estimate BF%, fat mass (FM), and lean body mass (LBM). Performance was assessed via vertical jump (VJ), bench press 1 RM (BP), and back squat 1 RM (BS).
Arm CSA increased significantly (p < .05) in BET but not PL. No differences existed between group and time for changes in thigh CSA. Back squat training volume increased significantly (p < .05) for both groups throughout training. Bench press training volume was significantly (p < .05) improved for BET compared to PL at microcycles one and three. Body composition (BF%, FM, LBM) improved significantly (p < .05) in BET but not PL. No differences were found in performance variables (BP, BS, VJ) between groups, except there was a trend (p = .07) for increased VJ power in BET versus PL. A significant interaction (p < .05) existed for HCTL, with increases from BL to week 2 in PL, but not BET. Additionally, HCTL remained elevated at week 4 in PL, but not BET.
Six-weeks of betaine supplementation improved body composition, arm size, bench press work capacity, attenuated the rise in urinary HCTL, and tended to improve power (p = .07) but not strength.
... Of the studies included in the review, only two assessed blood lactate before and after exercise, demonstrating a reduction in lactate levels even with an increase in the number of repetitions, reflecting the difference in lactate production and elimination rates, as well as a positive effect on exercise time and condition for lactate during the leg press 1-RM test (Machek, et al. 2022). A study by Trepanowski et al. (2011) indicates a lower accumulation of blood lactate induced by exercise during betaine supplementation versus placebo supplementation. The authors suggest that the lower lactate accumulation, associated with betaine's cellular hydration maintenance effect, may have contributed to exercise performance (Trepanowski, et al. 2011). ...
... A study by Trepanowski et al. (2011) indicates a lower accumulation of blood lactate induced by exercise during betaine supplementation versus placebo supplementation. The authors suggest that the lower lactate accumulation, associated with betaine's cellular hydration maintenance effect, may have contributed to exercise performance (Trepanowski, et al. 2011). Arazi et al. (2022) speculate that one possible explanation for post-exercise blood lactate levels being lower may be the ability of betaine supplementation to improve mitochondrial respiration, resulting in increased lactate oxidation. ...
Objectivos: Esta revisão sistemática investigou a influência da suplementação com betaína na fadiga muscular durante o exercício. Metodologia: Para o efeito foram utilizadas as diretrizes PRISMA e o estudo foi registado no PROSPERO (CRD42023469111). As pesquisas foram realizadas utilizando palavras-chave específicas de acordo com a estratégia PICOS no dia 12 de março de 2024 nas bases de dados PubMed, Cochrane Library, Web of Science, Embase e SCOPUS. Incluímos ensaios clínicos randomizados (ECR) em adultos de ambos os sexos que utilizaram a betaína como suplemento, em comparação com o placebo, para melhorar a fadiga muscular durante o exercício físico. Foram excluídos os estudos em animais e os estudos com uso concomitante de betaína e outros suplementos. A fadiga muscular foi avaliada pelo teste de uma repetição máxima e lactato sanguíneo durante exercícios leg-press, ou agachamento e supino. O risco de viés dos estudos incluídos foi avaliado pela ferramenta Cochrane RoB2 e a certeza da evidência pelo GRADE. Resultados: Foram incluídos cinco ECR, nos quais foram avaliados um total de 93 participantes; todos eram do sexo masculino, sendo que 57 indivíduos foram designados para o grupo de intervenção com uma média de idades de 19,18±2,67 anos, e 58 indivíduos do grupo de controlo com uma média de idades de 19,66±2,44 anos. A betaína promoveu mais repetições até à fadiga muscular no leg-press ou agachamento (n = 3) e no supino (n = 2), com níveis mais baixos de lactato sérico em dois estudos. Conclusões: A betaína pode ser considerada um potencial recurso ergogénico para melhorar a fadiga muscular, proporcionar um maior número de repetições nos exercícios e eliminar o lactato sanguíneo.
... The only studies that have described muscle oxygenation in the deltoid muscle during a bench press exercise using NIRS (albeit with a different device: InSpectra TM Tissue Oxygenation Monitor, Hutchinson Technology, Hutchinson, MN, USA) have been cross-over, placebo-controlled trials examining the impact of a dietary supplement [20,22]. Both studies had male participants perform 10 sets of bench press to muscular failure using a load equal to 50% of 1-RM. ...
... Both studies had male participants perform 10 sets of bench press to muscular failure using a load equal to 50% of 1-RM. When examining the mean difference between SmO 2 start and SmO 2 stop values for each set during the placebo trials, Trepanowski et al. [22] reported ∆%SmO 2 of approximately 35%, and Bloomer et al. [20] reported ∆%SmO 2 of approximately 47%. Therefore, these studies reported lower ∆%SmO 2 during each set as compared to those reported in our current study (~72.7%). ...
Research examining the changes in muscle oxygen saturation across multiple sets of resistance exercise is limited. The purpose of this study was to describe the physiological response of muscle oxygenation parameters during upper-body resistance exercise and examine the differential effects of relevant participant characteristics on resistance training performance and muscle oxygen saturation dynamics. Sixty-one recreationally trained men (n = 44; 21.8 ± 2.6 years) and women (n = 17; 20.2 ± 1.8 years) completed five-repetition maximum sets of barbell bench presses at a load equal to 75% 1-RM with a 2 min rest interval. Muscle oxygen saturation (SmO2) dynamics within the anterior deltoid were monitored using a portable near-infrared spectroscopy sensor. The percent change in SmO2 (∆%SmO2), the muscle oxygen re-saturation rate (SmO2RecSlope), and the highest measured SmO2 value during recovery periods (SmO2Peak) were measured. Two-way (sex [men, women] x time [sets 1–5]) repeated measures analyses of variance (ANOVA) were performed on muscle saturation variables. To examine the effect of relevant controlling variables, separate analyses of covariance (ANCOVA) with repeated measures were also performed. No differences were seen with ∆%SmO2 across sets. The main effects for sets occurred for SmO2RecSlope, whereby a decline was noted on sets 4 and 5 (p = 0.001) compared to set 1. Additionally, SmO2Peak was the lowest on set 5 (p < 0.001) compared to all other sets. Moreover, body mass (p = 0.013), diastolic blood pressure (p = 0.044), and mean arterial pressure (p = 0.033) for ∆%SmO2 were the only significant covariates noted amongst the muscle oxygenation variables. In conclusion, no sex differences and only a few set differences in muscle oxygen saturation dynamics were seen without employing any covariates. Body mass, diastolic blood pressure, and mean arterial pressure were identified as factors that could influence observed responses.
... Thus, BRJ ingestion caused elevation of both nutrients in plasma, with a higher increase of circulating betaine. One study showed that betaine supplementation of 6 g per day for 7 days induced a near-threefold increase in blood NOx (41), but this observation was not confirmed by later studies (42,43). Chronic intake of betaine at 2.5 g per day for 14 days (42,43), as well as acute intake of betaine at 1.25 and 5.00 g (42), has not been shown to modify plasma NOx levels. ...
... One study showed that betaine supplementation of 6 g per day for 7 days induced a near-threefold increase in blood NOx (41), but this observation was not confirmed by later studies (42,43). Chronic intake of betaine at 2.5 g per day for 14 days (42,43), as well as acute intake of betaine at 1.25 and 5.00 g (42), has not been shown to modify plasma NOx levels. Therefore, it seems plausible that other nutrients present in BRJ (14), rather than betaine, can cause higher plasma NOx elevation. ...
Background: Modification of the nitrate (NO3)-nitrite (NO2)-nitric oxide (NO) pathway can be induced by oral intake of inorganic NO3 (NIT) or NO3-rich products, such as beetroot juice (BRJ).
Objectives: The primary aim of this study was to evaluate the plasma changes in betaine, choline, trimethylamine (TMA), trimethylamine N-oxide (TMAO), and NO3/NO2 (NOx) concentrations over 4 h after single oral ingestion of NIT or BRJ. The flow-mediated skin fluorescence (FMSF) method was applied to measure the changes in nicotinamide adenine dinucleotide reduced form (NADH) in response to transient ischemia and reperfusion. We hypothesized that various sources of NO3 may differently affect endothelial and mitochondrial functions in healthy human subjects.
Methods: In a randomized crossover trial, 8 healthy young adults ingested 800 mg NO3 from either NIT or BRJ on 2 separate days with ≥3 d apart. Venous blood samples were collected every hour, and FMSF determination was applied bihourly.
Results: Plasma betaine and choline concentrations peaked at 1 h after BRJ ingestion, and remained significantly higher than baseline values at all time points (P < 0.001 and P < 0.001, compared to preingestion values). Over time, BRJ was more effective in increasing NOx compared with NIT (fixed-trial effect P < 0.001). Baseline fluorescence decreased after both NIT and BRJ consumption (fixed-time effect P = 0.005). Transient ischemia and reperfusion response increased because of NO3 consumption (fixed-time effect P = 0.003), with no differences between trials (P = 0.451; P = 0.912; P = 0.819 at 0, 2, and 4 h, respectively).
Conclusions: Acute ingestion of BRJ elevated plasma betaine and choline, but not TMA and TMAO. Moreover, plasma NOx levels were higher in the BRJ trial than in the NIT trial. Various sources of NO3 positively affected endothelial and mitochondrial functions. This trial was registered at clinicaltrials.gov as NCT05004935.
... On the other hand, 6 weeks of betaine supplementation did not improve CrossFit specific anaerobic performance or 2 km row time in recreational CrossFit athletes [38], neither 2 weeks of supplementation improved anaerobic Wingate performance in untrained men [39]. Additionally, some [38][39][40][41], but not all [42] studies, have shown improvements in muscular strength and power with betaine supplementation. ...
... In regards to potential mechanisms, intracellular betaine defends citrate synthase, the first rate limiting enzyme in the Krebs cycle [77], against thermos-denaturation [78]. This likely leads to greater muscle oxygen consumption, as evidenced by the reported reduced muscle tissue oxygen saturation despite increased muscular endurance with betaine supplementation [41], and may partially explain the increase in aerobic performance observed in this study. ...
Objective
Various nutritional strategies are adopted for athletes to maintain and to improve performance during the competition season. Betaine may enhance performance during a competitive season by increasing the testosterone to cortisol ratio and reducing systemic inflammation. The aim of this study was to investigate the effect of betaine supplementation on the bio-motor abilities in young professional soccer players.
Methods
Twenty-nine young professional soccer players (age, 15.5±0.3 years) were matched by position and randomly assigned to one of two groups for 14 weeks: betaine (BG, 2 g/day; n =14) or placebo (PG n =15). Diet was standardized by a nutritionist, and measures of muscular power (countermovement jump: CMJ), change of direction: modified 5-0-5), acceleration (10 m sprint), sprint performance (30 m sprint time: SpT), muscular strength (leg press and bench press one repetition maximum: 1-RM), repeated sprint ability (running-based anaerobic sprint test: RAST), and aerobic capacity (30-15 intermittent fitness test) were assessed in the pre (P1), mid (P2) and post (P3) season over the course of 5 days. All subjects participated in one soccer match and five training sessions per week.
Results
Significant ( p < 0.05) group x time interactions were found for maximal oxygen uptake (VO 2max ), anaerobic peak power, and muscular strength favoring BG at P2 and P3 compared to P1. There were meaningful ( p < 0.05) group x time interactions for CMJ, SpT, and peak power during the RAST that favored the BG.
Conclusions
14-week of betaine supplementation increased predicted 1-RM, VO 2max , and repeated sprint ability performance in youth professional soccer players. Betaine supplementation seems to be a useful nutritional strategy to improve and to maintain performance during a competitive soccer season.
... On the other hand, 6 weeks of betaine supplementation did not improve CrossFit speci c anaerobic performance or 2 km row time in recreational CrossFit athletes [34], neither did 2 weeks of supplementation improve anaerobic Wingate performance in untrained men [35]. Additionally, some [34][35][36][37], but not all [38] studies, have shown improvements in muscular strength and power with betaine supplementation. ...
... In these studies, the training was composed of moderate loads and higher repetitions (~ 10), and given heavier loads (> 85% . This likely leads to greater muscle oxygen consumption, as evidenced by the reported reduced muscle tissue oxygen saturation despite increased muscular endurance with betaine supplementation [37], and may partially explain the increase in aerobic capacity observed in this study. ...
Objective
Various nutritional strategies are adopted for athletes to maintain and improve performance during the competition season. Betaine may enhance performance during a competitive season by increasing the testosterone to cortisol ratio and reducing systemic inflammation. The aim of this study was to investigate the effect of betaine supplementation on the bio-motor abilities in young soccer players.
Methods
Twenty-nine professional young soccer players (age, 15.5 ± 0.3 years) were matched by position and randomly assigned to one of two groups for 14 weeks: betaine (BG, 2 g/day; n = 14) or placebo (PG n = 15). Diet was standardized by a nutritionist, and measures of muscular power (countermovement jump: CMJ), change of direction (modified 5-0-5), acceleration (10 m sprint), sprint performance (30 m sprint time: SpT), muscular strength (leg press and bench press 1-RM), repeated sprint ability (running-based anaerobic sprint test: RAST), and aerobic capacity (30 − 15 intermittent fitness test) were assessed in the pre (P1), mid (P2), and post (P3) season over the course of 5 days. All subjects participated in one soccer match and five training sessions per week.
Results
Significant (p < 0.05) group x time interactions were found for maximal oxygen uptake (VO2max), anaerobic peak power, and muscular strength favoring BG at P2 and P3 compared to P1. There were meaningful (p < 0.05) group x time interactions for CMJ, SpT, and peak power during the RAST that favored the BG.
Conclusion
14-week of betaine supplementation increased 1-RM, VO2max, and repeated sprint ability performance in youth professional soccer players. Betaine supplementation seems to be a useful nutritional strategy to improve and maintain performance during a competitive soccer season.
... Betaine also has the potential to prime the glycolytic pathway by increasing NAD+ by accepting nucleophilic H+ from NADH, yielding DMG, CH 4 , and the oxidation of NADH to NAD+ (20). However, research on this has been contradictory as Armstrong et al. (2) found an increase in lactate during sprinting, whereas Trepanowski et al. (42) found no difference in lactate during high repetition bench press. It has been reported that betaine administration elevates blood levels of nitric oxide (NO) (25). ...
... A follow-up study by Hoffman et al. (23) found betaine supplementation did not promote significant increases in either peak or concentric force during the isokinetic chest press (23). These findings were consistent with a study by Trepanowski et al. (42) that investigated the effects of betaine supplementation on bench press power and isometric force, leg press isometric force, vertical jump height, and chest press repetitions to fatigue. That study also found no significant improvements from betaine for exercise performance variables; however, there was a moderate increase in total repetitions, total repetitions to fatigue, and volume load in the bench press (42). ...
Dietary supplements are commonly used by athletes to optimize body composition and/or performance in sport. Trimethylglycine, better known as betaine, is a popular ingredient in sports supplements that has been claimed to enhance performance and lean mass. This article aims to review the current state of the literature as to the potential ergogenic effects of betaine on muscular strength, power, and body composition and draw evidence-based conclusions as to its use as a sports supplement. Animal models indicate beneficial effects of betaine on improvements in body composition; the literature investigating these effects in humans is promising but limited. There are various mechanisms by which betaine may facilitate increases in muscle strength and power; however, the current literature does not seem to support a beneficial effect on these outcomes. Given that betaine does not seem to be associated with any side effects, its short-term use may be worth considering for athletes seeking improved body composition until further research provides more definitive evidence on the topic. The lack of data on long-term safety warrants caution for its continued use.
... Arterial oxygen saturation is directly linked to the amount of oxygen being circulated to working muscle (Neto et al., 2014). Oxygen saturation levels can provide insight into the availability of oxygen to the working muscle post exercise (Trepanowski et al., 2011) and efficiency of respiration (Poets & Veloso, 2020). Slow breathing has been shown to increase arterial oxygen saturation and improve performance (Bernardi et al., 1998). ...
... Al., 2017). The MLAT used in this study may not be applicable to basketball but produced effects consistent with high intensity exercise (Trepanowski et al., 2011;Sim, Wallman, Fairchild & Guelfi, 2013;Read et. al., 2014;Keir et al., 2015;Osawa, Shiose & Takahashi, 2017). ...
Slow breathing interventions have been utilized since around 5000Bc (Nivethitha, Mooventhan & Manjunath, 2016). More recently breathing therapies have found a slow breathing intervention can influence vagal tone and the baroreflex (Russo, Santarelli & O'Rourke, 2017). At the elite level of sport coaches and athletes apply a variety of techniques and strategies to gain an advantage in performance and recovery (Dupuy, Douzi, Theurot, Bosquet & Dugué, 2018). A study was conducted to mimic the demands of basketball to see if a slow breathing intervention could produce an improvement in performance and recovery. Participants (n=10) completed 4 rounds of a modified lane agility test (MLAT). The experimental group performed a slow breathing intervention (4 second inhale 8 second exhale) in between rounds. Data collected regarding heart rate, oxyhaemoglobin saturation, RPE, MLAT and blood lactate was analysed using Rstudio (R version 3.5.1). significant difference was determined using two-way ANOVAS and t-tests. Cohen's d was used to measure effect size between groups. All statistical analysis was performed using 95% CI (p=≤0.05). The study found that the slow breathing intervention produced a moderate to very large (d=0.91 to 2.50) effect on reducing blood lactate levels at multiple measurement points. These findings provide a proof of concept for future research and suggest slow breathing intervention may be effective in improving recovery and performance.
... Participants were also asked not to discuss their treatments with other volunteers. The rationale behind the selection of 2.5 g/day as the treatment dosage is based on previous findings demonstrating that this is a sufficient dose to increase betaine plasma levels and to promote strength performance [25,26]. Other authors referred that a dosage of 34.8-36.3 ...
... The first study that proposed an ergogenic role of betaine in muscle endurance and performance was conducted in patients with poliomyelitis in 1952 [14]. Later, Armstrong et al. [18] observed a positive effect on oxygen consumption and lactate concentration after betaine administration, results confirmed by others after high-intensity end strenuous endurance exercise [26,37]. It seems that betaine increase Krebs cycle function, reducing the thermodegradation of citric synthase and thus improving aerobic capacity [38]. ...
We aim to investigate the effect of 6 weeks of betaine supplementation on body composition and muscle performance during CrossFit© training. Twenty-nine subjects matched for training status (4.16 0.95 day/week) and body fat mass (12.66 4.08%) were randomly assigned to a betaine (BET; N = 14) or placebo group (PLA; N = 15). Body composition and cellular hydration were estimated with skinfolds measurement and bioelectrical impendence before and after 6 weeks of training. Muscle performance was assessed using three different tests: 3-RM back-squat for muscle strength, 2 km rowing test for aerobic capacity and Bergeron Beep Test for anaerobic capacity. Muscle strength assessed during back squat significantly increased in BET (p = 0.04) but not in the PLA group, however, there were no statistical differences between groups. Although not significant, fat mass was reduced in BET compared to PLA. Overall, body composition and cell hydration measurements did not change in response to training or betaine supplementation. Short-term (6 weeks) betaine supplementation supports muscle strength but was not ergogenic for trained subjects to aerobic and anaerobic performance in the CrossFit©-specific test.
... In a follow-up study, the same group (58) found no effect of 15 days of betaine supplementation (2.5 g/d) on peak concentric or eccentric power during an isokinetic chest press in active college-aged men. These results are in agreement with Trepanowski et al. (123) who observed no significant improvements in lower-(vertical jump) or upper-body (bench press throw) muscular power after 14 days of betaine supplementation (2.5 g/d) in resistance-trained men. Nevertheless, a significant increase Promotes a transient, but not sustained, muscle protein synthesis response compared with a complete protein source May accelerate recovery and reduce muscle damage (yet, studies have not compared with a complete protein source) The use of isolated BCAAs or leucine for increasing gains in strength and hypertrophy is not supported in the current research BCAA supplements likely offer limited utility compared with complete protein sources When ingesting an optimal amount of protein ($1.6 g/kg/d), BCAA supplementation would likely offer negligible effects on body composition and strength HMB 3 g/d Increased muscle protein synthesis ...
... in total repetitions and total volume load was noted during a 10-set bench press protocol after betaine supplementation (123). A lack of significant increase in measures of muscular strength (bench press and squat 1RM) and power (maximal-velocity repetitions for the bench press and squat exercises using 60% 1RM) has also been observed in untrained men supplemented with 2 g/d of betaine for 10 days (29). ...
Several dietary supplements have been proposed as a means of improving muscle strength and hypertrophy when combined with resistance training. However, few have received sufficient attention from sports scientists to produce robust evidence for being well recommended. A growing body of literature has emerged for several dietary ingredients with the potential to promote muscular adaptations. Therefore, the aim of this review is to provide an evidence-based review of the efficacy of emerging nutritional supplements to allow athletes, coaches, and practitioners to make an informed decision when considering their use as a means of improving muscle strength and hypertrophy.
... The second day of testing was completed the next day at a similar time. On this day and after completion of a standardized warm-up consisting of whole-body movement and flexibility activities, upper and lower body strength endurance were assessed using a five set to fatigue protocol at 70% 1 RM for bench press and back squat [21,22]. Repetitions completed during each set were recorded. ...
... The second day of testing was completed at a similar time and consisted of modified strength endurance according to the methods of Trepanowski et al. [22] and Ferguson et al. [21]. These tests entailed completing five sets of bench press and back squat repetitions to fatigue at a load equivalent to 70% of their 1 RM. ...
Beta-alanine (BA) is a precursor to carnosine which functions as a buffer assisting in the maintenance of intracellular pH during high-intensity efforts. Rugby is a sport characterized by multiple intermittent periods of maximal or near maximal efforts with short periods of rest/active recovery. The purpose of this pilot study was to evaluate the impact of six weeks of beta-alanine supplementation on anaerobic performance measures in collegiate rugby players. Twenty-one male, collegiate rugby players were recruited, while fifteen completed post-testing (Mean ± SD; Age: 21.0 ± 1.8 years, Height: 179 ± 6.3 cm, Body Mass: 91.8 ± 13.3 kg, % Body Fat: 21.3 ± 4.4). Supplementation was randomized in a double-blind, placebo-controlled manner between 6.4 g/d of beta-alanine and 6.4 g/d of maltodextrin placebo. Body composition, upper and lower-body maximal strength and muscular endurance, intermittent sprint performance, and post-exercise lactate, heart rate, and rating of perceived exertion were assessed before and after supplementation. Data were analyzed using a 2 × 2 (group × time) mixed factorial analysis of variance (ANOVA) with repeated measures on time. No significant interaction effects were noted for body mass, fat mass, fat-free mass, and percent bodyfat (p > 0.05). No performance effects resulting from beta-alanine supplementation were detected. Results from this initial pilot investigation suggest that BA exerts little to no impact on body composition parameters, muscular strength, muscular endurance, or intermittent sprinting performance. With the limited research exploring the impact of BA in this sporting context, these initial findings offer little support for BA use, but more research is needed to fully understand the potential impact of BA on various aspects of resistance exercise performance.
... Betaine (trimethylglycine) is a naturally-occurring derivative of the amino acid glycine which may improve exercise performance by increasing rates of creatine synthesis, elevating levels of blood nitric oxide, and promoting fluid and thermal homeostasis [29,30]. Chronic supplementation with 1.25-2.5 g per day of betaine has been demonstrated to enhance repetitions to fatigue and total volume load completed during resistance exercise [29,30], with improvements in power and force production also reported [31]. ...
... Betaine (trimethylglycine) is a naturally-occurring derivative of the amino acid glycine which may improve exercise performance by increasing rates of creatine synthesis, elevating levels of blood nitric oxide, and promoting fluid and thermal homeostasis [29,30]. Chronic supplementation with 1.25-2.5 g per day of betaine has been demonstrated to enhance repetitions to fatigue and total volume load completed during resistance exercise [29,30], with improvements in power and force production also reported [31]. However, the dosages used in these investigations are far higher than those found in a typical MIPS. ...
In recent years, a new class of dietary supplements called multi-ingredient pre-workout supplements (MIPS) has increased in popularity. These supplements are intended to be taken prior to exercise and typically contain a blend of ingredients such as caffeine, creatine, beta-alanine, amino acids, and nitric oxide agents, the combination of which may elicit a synergistic effect on acute exercise performance and subsequent training adaptations compared to single ingredients alone. Therefore, the purpose of this article was to review the theoretical rationale and available scientific evidence assessing the potential ergogenic value of acute and chronic ingestion of MIPS, to address potential safety concerns surrounding MIPS supplementation, and to highlight potential areas for future research. Though direct comparisons between formulations of MIPS or between a MIPS and a single ingredient are challenging and often impossible due to the widespread use of "proprietary blends" that do not disclose specific amounts of ingredients in a given formulation, a substantial body of evidence suggests that the acute pre-exercise consumption of MIPS may positively influence muscular endurance and subjective mood, though mixed results have been reported regarding the acute effect of MIPS on force and power production. The chronic consumption of MIPS in conjunction with a periodized resistance training program appears to augment beneficial changes in body composition through increased lean mass accretion. However, the impact of long-term MIPS supplementation on force production, muscular endurance, aerobic performance, and subjective measures is less clear. MIPS ingestion appears to be relatively safe, though most studies that have assessed the safety of MIPS are relatively short (less than eight weeks) and thus more information is needed regarding the safety of long-term supplementation. As with any dietary supplement, the use of MIPS carries implications for the athlete, as many formulations may intentionally contain banned substances as ingredients or unintentionally as contaminants. We suggest that athletes thoroughly investigate the ingredients present in a given MIPS prior to consumption. In conclusion, it appears that multi-ingredient pre-workout supplements have promise as an ergogenic aid for active individuals, though further information is required regarding long-term efficacy and safety in a wider variety of populations.
... Betaine is high in other foods such as wheat bran, wheat germ, spinach, beets, and wheat bread, although exact values will vary highly with different sources and cooking methods [2]. The average betaine intakes in adult humans are approximately 100-400 mg/day [3], however the ergogenic and clinical effects of betaine have been investigated with doses ranging from 500 to 20,000 mg/day [4][5][6][7][8]. ...
... Since most studies that have reported improvements in performance have employed exercise tests that involved repeated higher intensity efforts [6,20], therefore we previously hypothesized that betaine may be most ergogenic in testing and training protocols that impose a high metabolic demand [1]. Metabolic stress increases the cellular uptake of betaine which results in increased cytoplasmic osmolality, biopolymer hydration, and helps to maintain biochemical function during stress by protecting ATPase and myosin heavy-chain proteins again urea denaturation [18], attenuating reductions in the affinity of Ca 2+ for troponin [52], and defending citrate synthase against thermodenaturation [53]. ...
Background:
Betaine supplementation has been shown to improve body composition and some metrics of muscular performance in young men; but, whether betaine enhances body composition or performance in female subjects is currently unknown. Therefore, the purpose of this study was to investigate the interaction between resistance training adaptation and chronic betaine supplementation in females.
Methods:
Twenty-three young women (21.0 ± 1.4 years, 165.9 ± 6.4 cm, 68.6 ± 11.8 kg) without prior structured resistance training experience volunteered for this study. Body composition (BodPod), rectus femoris muscle thickness (B-mode Ultrasound), vertical jump, back squat 1RM and bench press 1RM were assessed pre- and post-training. Following 1 week of familiarization training, subjects were matched for body composition and squat strength, and randomly assigned to either a betaine (2.5 g/day; n = 11) or placebo (n = 12) group that completed 3 sets of 6-7 exercises per day performed to momentary muscular failure. Training was divided into two lower and one upper body training sessions per week performed on non-consecutive days for 8 weeks, and weekly volume load was used to analyze work capacity.
Results:
Significant main effects of time were found for changes in lean mass (2.4 ± 1.8 kg), muscle thickness (0.13 ± 0.08 cm), vertical jump (1.8 ± 1.6 cm), squat 1RM (39.8 ± 14.0 kg), and bench press 1 RM (9.1 ± 7.3 kg); however, there were no significant interactions. A trend (p = .056) was found for greater weekly training volumes for betaine versus placebo. Significant interactions were found for changes in body fat percentage and fat mass: body fat percentage and fat mass decreased significantly more in betaine (- 3.3 ± 1.7%; - 2.0 ± 1.1 kg) compared to placebo (- 1.7 ± 1.6%; - 0.8 ± 1.3 kg), respectively.
Conclusions:
The results of this study indicated that betaine supplementation may enhance reductions in fat mass, but not absolute strength, that accompany a resistance training program in untrained collegiate females.
... In skeletal muscle, previous reports show that betaine increases skeletal muscle creatine content and enhances muscle strength and power performance during exercise [13][14][15]. Huang et al. further find that betaine could reduce muscle fatty acid oxidation and elevate intramuscular fat (IMF) content in finishing pig [16]. In addition, another study reveals that long-term betaine supplementation enhances muscle lipid deposition while not altering other physiological characteristics of Alentejano pig [17]. ...
... In addition, we found that betaine treatment could alter lipid metabolism in skeletal muscle cell. Since betaine can improve muscle strength and power performance during exercise by increasing skeletal muscle creatine content [13,14], our results suggest that it is necessary to investigate the concentration and treatment time of betaine when used to improve exercise performance. ...
Betaine, a neutral zwitterionic compound, could regulate intramuscular fat (IMF) deposition and meat quality. However, the efficacy is controversial. Moreover, the regulatory mechanism of betaine on lipid metabolism in skeletal muscle cells remains unclear. Therefore, in this study, we examined the effects and regulatory mechanism of betaine on lipid accumulation in adipogenic-differentiated C2C12 cells. We found that adipogenic-induced C2C12 cells treated with 10 mM betaine for 24 and 48 h had more lipid accumulation than the control group. Real-time PCR and Western blot results revealed that betaine treatment did not alter the expression of lipolysis and lipid oxidation-related genes, but dramatically increased the expression of peroxisome proliferator-activated receptor γ (PPARγ) and its target genes such as fatty acid binding protein 4 (aP2), fatty acid synthase (FAS) and lipoprteinlipase (LPL). Furthermore, betaine combined with PPARγ inhibitor GW9662 treatment showed that betaine elevated C2C12 lipid accumulation through upregulation of PPARγ. Mechanistically, we found that betaine promoted PPARγ expression and lipid accumulation through inhibition of extracellular regulated protein kinases1/2 (ERK1/2) signalling pathway. These results demonstrate that betaine acts through ERK1/2-PPARγ signalling pathway to regulate lipid metabolism in adipogenic-differentiated skeletal muscle cells, which could provide some useful information for controlling muscle lipid accumulation by manipulating ERK1/2 and PPARγ signalling pathway.
... For example, betaine has been shown to favorably enhance performance outcomes. 6 However, the additive or synergistic effects of the constituents contained within BRJ have not been extensively studied. Nevertheless, both anecdotal and scholarly evidence supports the use of BRJ to produce faster finish times, 7,8 increase time to exhaustion, [9][10][11] reduce steadystate oxygen (O 2 ) consumption, 9,10 increase peak power, 7,12 and increase work rate at the gas exchange threshold 12 (see Table 1). ...
... 11 In addition, only three studies to date have been published that investigate the use of betaine (a major BRJ constituent) on resistance exercise performance. 6,28,29 The findings from these betaine studies are equivocal, with the overarching theme being a modest improvement in resistance exercise performance. ...
Increased sales and consumption of organic and natural foods reflect consumers heightened interest in promoting health and improving athletic performance. Of these products, beetroot and its constituents have become increasingly popular in the arena of exercise performance, mainly due to the high concentrations of nitrate. Studies have indicated beetroot juice (BRJ) may improve exercise time to exhaustion, running performance, and increase muscular efficiency during moderate intensity exercise. The purpose of this review is to examine the efficacy of BRJ to serve as an ergogenic aid in athletic performance. It appears that BRJ may provide modest performance enhancement; however, more research is needed to clearly identify mechanisms of action and proper dosing patterns to maximize the performance benefits of BRJ.
... Betaine (trimethyglycine: TMG) is another widely used dietary supplement that has also been shown to enhance exercise performance in resistance-trained individuals. A recent randomized, double-blind study reported significant increases in total repetitions (P=0.01) and total volume load (P=0.02) in a 10-set bench press protocol with betaine supplementation [12]. Mechanistically, significant reductions (P=0.01) in muscle tissue oxygen saturation during the bench press protocol in the betaine supplementation group were found, suggesting that enhanced muscle oxygen consumption and/or extraction might be the result of betaine use. ...
... Moreover, caffeine stimulates the CNS by antagonizing adenosine receptors, thereby inhibiting the negative effects adenosine induces on neurotransmission, arousal, and pain perception [16,17]. In short, caffeine is commonly used and accepted for its ability to promote wakefulness, enhance focus and concentration and to prevent the central perception of fatigue [12]. ...
In this prospective, randomized, double-blind, trial conducted in two parts, we examined the effects of a multi-ingredient pre-exercise workout supplement blend of creatine, betaine and a dendrobium extract (MMP) on safety, performance, and body composition in healthy men and women undergoing a supervised program of resistance exercise. Part 1 was an acute hemodynamic safety study wherein forty young, healthy men and women (26.2 ± 5.3 years, 70.4 ± 3.3 inches, 83.7 ± 14.9 kg, 26.0 ± 3.2 kg●m(-2)) ingest one dose of either the MMP or comparator in a randomized, double-blind, comparator controlled, crossover fashion before having their resting heart rate, blood, ECG and comprehensive blood chemistry and blood counts completed. Systolic (SBP) and diastolic (DBP) blood pressures were generally raised (3.0-5.4 mm Hg, p<0.01) following supplementation with MPP whereas in the comparator group SBP was marginally reduced by 0.3 to 1.2 mm Hg, p>0.05 at all time points) and DBP was increased (3.0 - 3.9 mm Hg, p<0.05 at all time points). No changes in EKG-corrected QT interval were observed, and no serious adverse events were reported. Part 2 was a six-week training study wherein forty-three young, healthy men and women (24.3 ± 2.9 years, 70.5 ± 3.1 inches, 83.8 ± 9.6 kg, 26.1 ± 2.7 kg●m(-2)) supplemented with daily pre-workout doses of either the MPP or a comparator in a randomized, double-blind, comparator-controlled fashion while following a standardized resistance training program for six weeks. MPP and the comparator were isocaloric and delivered the same amount of caffeine. Significant improvements in visual analog scale (VAS) scores for energy (p<0.024) and concentration (p<0.041) were found along with consistently higher levels of focus accompanied by less fatigue when MPP was consumed in comparison to comparator during upper body muscular strength-endurance tests at weeks 3 and 6. MPP supplementation for 6 weeks did not improve dual-energy x-ray absorptiometry (DEXA) measures of body composition or objective assessments of exercise performance. Overall, MPP use and administration was well tolerated. Self-reported scores for energy and concentration were significantly greater. Over a six-week training and supplementation period, MPP use was not associated with improvements in performance or body composition. Future studies should confirm these effects over a more prolonged training period.
... In addition to clinical therapeutic settings, betaine supplementation has been used in athletic performance studies to explore the impact of betaine on exercise physiology. These studies report a variety of benefits and improved athletic performance, including improved anaerobic and aerobic metabolism, athletic performance, muscle endurance, and body composition (Trepanowski et al., 2011;Cholewa et al., 2013Cholewa et al., , 2014Nobari et al., 2021b;Arazi et al., 2022;Machek et al., 2022) in numerous individual and team sports, e.g., running, cycling, soccer. Consistent with clinical research, these athletic performance studies do not report negative or adverse consequences to betaine supplementation. ...
Betaine supplementation in the context of human nutrition, athletic performance, and clinical therapy demonstrate that the osmolyte and methyl donor, betaine, is cytoprotective and beneficial to human health. These studies also demonstrate that betaine supplementation in healthy humans is straight-forward with no reported adverse effects. Here, we explore betaine uptake in the central nervous system (CNS) and contribute to evidence that betaine may be uniquely protective to the brain. We specifically describe the therapeutic potential of betaine and explore the potential implications of betaine on inhibition mediated by GABA and glycine neurotransmission. The influence of betaine on neurophysiology complement betaine’s role as an osmolyte and metabolite and is consistent with clinical evidence of betaine-mediated improvements to cognitive function (reported in elderly populations) and its anti-convulsant properties. Betaine’s therapeutic potential in neurological disorders including epilepsy and neurodegenerative diseases combined with benefits of betaine supplementation on athletic performance support the unique application of betaine as a prophylaxis to concussion. As an example, we identify young athletes (15–24 years old), especially females, for prophylactic betaine supplementation to promote brain health and resilience in a cohort at high risk for concussion and for developing Alzheimer’s disease.
... Betaine supplementation has also been used to improve exercise outcomes in a handful of RCTs in healthy populations with differential effects in male and female subjects. In healthy males, betaine improved endurance and exercise quality [32e34] possibly through enhanced oxygen consumption [33], but did not affect serum lipid profile [35]. In healthy, strength-trained male subjects, betaine supplementation increased arm size and bench press work capacity compared to placebo [34]. ...
Background and Aims
Betaine supplementation has been shown to enhance hepatic lipid metabolism in obese mice and improve exercise performance in healthy populations. We examined effects of betaine supplementation, alone or in combination with treadmill exercise, on the metabolic consequences of high fat diet (HFD)-induced obesity in mice.
Methods and Results
Male C57BL/6J mice were fed chow or HFD. After 15 weeks, HFD mice were split into: HFD, HFD with betaine (1.5% w/v), HFD with treadmill exercise, and HFD with both betaine and exercise (15m/min for 45min, 6 days/week; n=12/group) for 10 weeks. Compared to HFD mice, body weight was significantly reduced in exercise and exercise-betaine mice, but not in mice given betaine alone. Similarly, adiposity was reduced by exercise but not by betaine alone. HFD-induced glucose intolerance was slightly improved by exercise, but not with betaine alone.
Significantly greater benefits were observed in exercise-betaine mice, compared to exercise alone, such that GTT-outcomes were similar to controls. This was associated with reduced insulin levels during ipGTT, suggesting enhanced insulin sensitivity. Modest benefits were observed in fatty acid metabolism genes in skeletal muscle, whilst limited effects were observed in the liver. HFD-induced increases in hepatic Mpc1 (mitochondrial pyruvate carrier 1) were normalised by all treatments, suggesting potential links to altered glucose metabolism.
Conclusions
Our data show that drinking 1.5% betaine was sufficient to augment metabolic benefits of exercise in obese mice. These processes appear to be facilitated by altered glucose metabolism, with limited effects on hepatic lipid metabolism.
... Commercial beetroot juice tested in studies (38,83) has ascorbic acid as a natural preservative. Previous studies have demonstrated positive effects of betalains themselves on sports performance (84,85). Thus, it is difficult to conclude that the effect of nitrate ingestion through vegetables with high nitrate content and their derivative products is exclusively due to the nitrate, but rather due to the synergy between these compounds (29,86). ...
To identify how variables such as exercise condition, supplementation strategy, participant characteristics and demographics, and practices that control oral microbiota diversity could modify the effect of inorganic nitrate ingestion (as nitrate salt supplements, beetroot juice, and nitrate-rich vegetables) on exercise performance, we conducted a systematic review with meta-analysis. Studies were identified in PubMed, Embase, and Cochrane databases. Eligibility criteria included randomized controlled trials assessing inorganic nitrate on exercise performance in healthy adults. To assess the variation in effect size, we used meta-regression models for continuous variables and subgroup analysis for categorical variables. One hundred and twenty-three studies were included in this meta-analysis totaling 1705 participants. Nitrate was effective for improving exercise performance (Standardized Mean Difference (SMD):0.101; 95% confidence intervals (95%CI):0.051,0.151, P < 0.001, I2 = 0%), although nitrate salts supplementation was not as effective (P = 0.629) as ingestion via beetroot juice (P < 0.001) or a high nitrate diet (P = 0.005). Practices that control oral microbiota diversity influenced the nitrate effect, with practices harmful to oral bacteria decreasing the ergogenic effect of nitrate. Nitrate ingestion was most effective for exercise lasting between 2 and 10min (P < 0.001). An inverse dose-response relationship between the fraction of inspired oxygen and the effect size (coefficient: -0.045;95%CI: -0.085, -0.005, P = 0.028) suggests that nitrate was more effective in increasingly hypoxic conditions. There was a dose-response relation for acute administration (P = 0.049). The most effective acute dose was between 5–14.9mmol provided ≥150min prior to exercise (P < 0.001). An inverse dose-response for protocols ≥ 2days was observed (P = 0.025), with the optimal dose between 5–9.9mmol∙day−1 (P < 0.001). Nitrate, via beetroot juice or a high nitrate diet, improved exercise performance, particular those lasting between 2–10min. Ingestion of 5–14.9mmol⋅day−1 taken at least 150min prior to exercise appears optimal for performance gains, while athletes should be aware that practices which control oral microbiota diversity may decrease the effect of nitrate.
... Chronic (6 to 10 weeks) betaine supplementation with 2.5 g/ day has been reported to enhance improvements in lean mass 6 and reductions in fat mass 7 that accompany resistance training. Sub-chronic (up to two weeks) betaine supplementation has been shown to improve upper and low body force output 8 , power output 8 , power output during cycle sprinting 9 , strength 10 , and muscular endurance 11 . However, within these aforementioned studies, improvements across variables and between studies is not consistent. ...
Objective: To analyse the acute effect of betaine supplementation on muscular endurance in weight training practitioners. Design: An experimental, crossover, randomized and double-blind study. Methods: The sample composed of 10 male subjects practicing resistance training (age: 23.71 ± 4.23 years old). Participants performed 2 sessions (i.e., Betaine x Placebo) with 3 sets of repetitions until failure with 70% of 1RM. The participants were provided 3 minutes of recovery between sets and 48 hours between sessions. The 24H food recall was evaluated before each exercise session. Results: There were no significant differences in carbohydrates (p = 0.732), protein (p = 0.684), fat (p = 0.271), or in total energy consumption (p = 0.865). A time effect occurred for the training session (F (2,18) = 54.626, p < 0.0001, η² = 0.859), with a linear reduction in the number of repetitions performed throughout the series for both conditions (1set > 2set > 3set). However, there was no interaction (F (2,18) = 0.625, p= 0.546, η² = 0.065) or condition effect (F(1,9) = 0.045, p = 0.837, η² = 0.005). Conclusion: Acute betaine supplementation had no effect on muscular endurance performance in the bench press.
... BET has been suggested to have effects on mitochondrial function. Endurance performance and resistance-based exercises such as running, squat repetitions, bench press throw, and vertical jumps, which are metabolically demanding tasks, were improved after BET administration [199][200][201][202]. Although the exact underlying mechanism was not investigated in those studies, one can speculate that the improved performance may be the result of enhanced mitochondrial energy metabolism. ...
Numerous naturally occurring molecules have been studied for their beneficial health effects. Many compounds have received considerable attention for their potential medical uses. Among them, several substances have been found to improve mitochondrial function. This review focuses on resveratrol, (–)-epicatechin, and betaine and summarizes the published data pertaining to their effects on cytochrome c oxidase (COX) which is the terminal enzyme of the mitochondrial electron transport chain and is considered to play an important role in the regulation of mitochondrial respiration. In a variety of experimental model systems, these compounds have been shown to improve mitochondrial biogenesis in addition to increased COX amount and/or its enzymatic activity. Given that they are inexpensive, safe in a wide range of concentrations, and effectively improve mitochondrial and COX function, these compounds could be attractive enough for possible therapeutic or health improvement strategies.
... To provide an estimate of oxygen saturation in the active musculature, a near-infrared spectroscopy (NIRS) device (MOXY, Hutchinson, MO, USA) was affixed to the anterior deltoid similar to previous work utilizing NIRS technology to monitor the bench press exercise [33]. Specifically, the surface of the skin was prepped with an alcohol swap and excess hair was removed if necessary. ...
The purpose of this study was to assess the impact of short-term dietary nitrate supplementation, in the form of red spinach extract (RSE), on bench press performance, muscle oxygenation, and cognitive function in resistance-trained males. Ten resistance-trained males participated in this randomized, cross-over, placebo-controlled, double-blind investigation. Each participant completed 7 days of either RSE (2 g; 180 mg NO3−) or a maltodextrin placebo (PL) in a counterbalanced fashion with a 14-day washout between treatments. During experimental visits, participants were provided their 8th and last dose of RSE or PL 40 min before completing 5 sets of the barbell bench press exercise to failure at 75% of a predetermined 1-repetition maximum with 2 min rest intervals. Mean and peak power were recorded via a linear transducer. Near-infrared spectroscopy (NIRS) was implemented to estimate muscle oxygenation, a Stroop Test was used to assess cognitive function, and subjective performance ratings were obtained in relation to the acute resistance exercise sessions. Data were analyzed via separate repeated measures analyses of variance. There were no time by group interactions for bench press repetitions (p = 0.549), peak power (p = 0.061), or mean power (p = 0.877) across the 5 sets of bench press. Additionally, no significant differences (p > 0.05) were observed for any measure of muscle oxygenation, Stroop performance, or subjective performance ratings. It appears that 7 days of RSE supplementation did not alter performance, muscle oxygenation, nor Stroop scores during or following the bench press exercise in resistance-trained males.
... Six to 10 weeks of betaine supplementation along with resistance training has been shown to decrease fat mass [15,16] and increase lean mass in previous studies [15]. Up to 2 weeks of betaine supplementation has shown improvements in upper and lower body force and power output [17], power output during cycle sprinting [18], strength [19], and muscular endurance [20]. These results provide a rationale whereby betaine supplementation may improve soccer performance by enhancing the power to mass ratio. ...
Objective
Betaine supplementation may enhance body composition outcomes when supplemented chronically during an exercise program. The purpose of this study was to evaluate the effect of betaine supplementation on development-related hormones, body composition, and anthropometrics in professional youth soccer players during a competitive season.
Methods
Twenty-nine players (age, 15.45 ± 0.25 years) were matched based upon position and then randomly assigned to a betaine group (2 g/day; n = 14, BG) or placebo group (PG, n = 15). All subjects participated in team practices, conditioning, and games. If a subject did not participate in a game, a conditioning protocol was used to ensure workload was standardized throughout the 14-week season. Growth hormone (GH), insulin-like growth factor-1 (IGF-1), testosterone, cortisol, height, weight, and body composition were assessed at pre-season (P1), mid-season (P2) and post-season (P3). Anthropometric variables were also measured following a one-year follow-up (F).
Results
Significant ( p < 0.05) group x time interactions were found for testosterone and testosterone to cortisol ratio (T/C). Both variables were greater in BG at P2 and P3 compared to P1, however, the testosterone was less in the PG at P3 compared to P2. There was no significant group by time interactions for GH, IGF-1, lean body mass, or body fat. There was a significant ( p < 0.05) group x time interaction in height and weight at F, with the greater increases in BG compared to PG.
Conclusion
Betaine supplementation increased testosterone levels and T/C ratio in youth professional soccer players during a competitive season. Betaine supplementation had no negative effects on growth (height and weight) and may attenuate reductions in testosterone due to intense training during puberty.
... Craig [12] indicated that active coupled sodium and chloride ions and passive sodium ion independent transport systems promote the cellular absorption of betaine. Based on this finding, most studies regarding betaine supplementation have used betaine mixed in a sports beverage, with the sports beverage employed as the placebo [23,24,[41][42][43]. Notably, sodium and chloride ions are essential electrolytes present in the blood and extracellular fluids. ...
This study evaluated the effects of 2 weeks of betaine supplementation on apoptosis, oxidative stress, and aerobic capacity after exhaustive endurance exercise (EEE). A double-blind, crossover, and counterbalanced design was adopted, with 10 healthy male participants asked to consume betaine (1.25 g of betaine mixed with 300 mL of sports beverage, twice per day for 2 weeks) or placebo (300 mL of sports beverage). All participants performed a graded exercise test on a treadmill to determine the maximal oxygen consumption (VO2max) before supplementation and then performed the EEE test at an intensity of 80% VO2max after 2 weeks of supplementation. The time to exhaustion, peak oxygen consumption, maximal heart rate, and average heart rate were recorded during the EEE test. Venous blood samples were drawn before, immediately after, and 3 h after the EEE test to assess apoptosis and the mitochondrial transmembrane potential (MTP) decline of lymphocytes as well as the concentrations of thiobarbituric acid reactive substance and protein carbonyl. The results indicated that lymphocyte apoptosis was significantly higher immediately after and 3 h after EEE than before exercise in participants in the placebo trial. However, lymphocyte apoptosis exhibited no significant differences among the three time points in participants in the betaine trial. Moreover, apoptosis in the betaine trial was significantly lower immediately after and 3 h after exercise compared with the placebo trial. No differences were noted for other variables. Thus, 2 weeks of betaine supplementation can effectively attenuate lymphocyte apoptosis, which is elevated by EEE. However, betaine supplementation exhibited no effects on MTP decline, oxidative stress, or aerobic capacity.
... When betaine was associated with wheel running exercise, we observed lower serum lipid peroxidation, compared with betaine alone. In previous human study, it has been noted that chronic betaine supplementation didn't induce changes in MDA concentrations [34]. Betaine does not directly interact with oxidants but interacts with S-adenosyl methionine (SAM), which has a direct antioxidant activity. ...
Purpose
The effect of 6 weeks of betaine (3.88 ± 0.49 g by kg of body weight per day) or C-phycocyanin (0.34 ± 0.0 g by kg of body weight per day) supplementation alone or in association with voluntary wheel running was tested on redox status.
Methods
Thirty Sprague-Dawley rats were randomly assigned to 6 groups: control, wheel activity, betaine with and without wheel activity, C-phycocyanin with and without wheel activity. At the end of the treatment, gastrocnemius, plasma and serum were collected on sacrificed animals. The levels of antioxidant activities (superoxide dismutase, catalase, glutathione peroxidase, total glutathione) and the myokine irisin were evaluated. Furthermore, the oxidative stress was quantified through the thiobarbituric acid reaction, and inflammation through Cyclooxygenase-2.
Results
Median running distance ranged from 4 to 6 km.day⁻¹ for the entire duration of the study, whatever the group. Results showed no effect of wheel running on antioxidant markers and oxidative stress, but an increased inflammation. Elevated activity of antioxidant enzymes was observed in betaine- or C-phycocyanin–treated rats both in plasma and gastrocnemius; however the Thiobarbituric acid reactive substance levels remained stable. For the wheel-running-coupled-to-diet group, the reduction of serum lipid peroxidation was stronger than the reduction observed in the diet-alone group. In any of the 6 groups, there were no correlations between irisin concentrations and lipid peroxidation or antioxidant parameters.
Conclusion
The diet supplementations alone appear to have stronger effects on redox balance than the exercise training alone. It could be interesting to evaluate whether betaine or C-phycocyanin could modulate the oxidative stress and inflammation, which occurs during pathologies such as cancer.
... Alternatively, systemic betaine augmentation has been linked to improved clinical outcomes in cognitive disorders such as epilepsy, Alzheimer's and other forms of dementia/cognitive deficits [11][12][13][14][15][16][17]. Betaine supplementation has also been shown to enhance athletic performance and protect against dehydration in the exercise physiology literature [18][19][20][21][22][23][24][25]. Taken together, these data suggest that betaine may have substantial therapeutic potential. ...
Betaine (N-trimethylglycine), a common osmolyte, has received attention because of the number of clinical reports associating betaine supplementation with improved cognition, neuroprotection and exercise physiology. However, tissue analyses report little accumulation of betaine in brain tissue despite the presence of betaine/GABA transporters (BGT1) at the blood brain barrier and in nervous tissue, calling into question whether betaine influences neuronal function directly or indirectly. Therefore, the focus of this study was to determine what capacity nervous tissue has to accumulate betaine, specifically in the hippocampus, a region of the brain associated with learning and memory and one that is particularly susceptible to damage (e.g., seizure activity). Here we report that hippocampal slices actively accumulate betaine in a time, dose and osmolality dependent manner, resulting in peak intracellular concentrations four times extracellular concentrations within 8 h. Our data also indicate that betaine uptake differentially influences the accumulation of other osmolytes. Under isosmotic conditions, betaine uptake minimally impacted some osmolytes (e.g., glycerylphosphorylcholine and glutamate) while significantly reducing others (taurine, creatine, and myo-inositol). Under osmotic stress (hyperosmotic) conditions, we observed dramatic changes in osmolytes like glycine and glutamine—key players in inhibitory neurotransmission—and little change in osmolytes such as taurine, creatine and myo-inositol when betaine was available. These data suggest that betaine may influence pathways of inhibitory neurotransmitter production/recycling in addition to serving as an osmolyte and metabolic intermediate. In sum, our data provide detailed characterization of betaine uptake in the hippocampus that implicates betaine in the modulation of hippocampal neurophysiology and neuroprotection.
... Betaine is commonly added to animal feeds to improve lean meat yield and quality in pigs and chickens (11,12) . Previous human studies have also indicated a potential ergogenic value of betaine on athletic performance in endurance-and strengthbased exercises (13,14) . However, evidence of its effect on human lean mass (LM) is limited. ...
Previous studies have demonstrated that betaine supplements increase lean body mass in livestock and improve muscle performance in human beings, but evidence for its effect on human lean mass is limited. Our study assessed the association of circulating betaine with lean mass and its composition in Chinese adults. A community-based study was conducted on 1996 Guangzhou residents (weight/mass: 1381/615) aged 50–75 years between 2008 and 2010. An interviewer-administered questionnaire was used to collect general baseline information. Fasting serum betaine was assessed using HPLC-MS. A total of 1590 participants completed the body composition analysis performed using dual-energy X-ray absorptiometry during a mean of 3·2 years of follow-up. After adjustment for age, regression analyses demonstrated a positive association of serum betaine with percentage of lean mass (LM%) of the entire body, trunk and limbs in men (all
P
<0·05) and LM% of the trunk in women (
P
=0·016). Each
sd
increase in serum betaine was associated with increases in LM% of 0·609 (whole body), 0·811 (trunk), 0·422 (limbs), 0·632 (arms) and 0·346 (legs) in men and 0·350 (trunk) in women. Multiple logistic regression analysis revealed that the prevalence of lower LM% decreased by 17 % (whole body) and 14 % (trunk) in women and 23 % (whole body), 28 % (trunk), 22 % (arms) and 26 % (percentage skeletal muscle index) in men with each
sd
increment in serum betaine. Elevated circulating betaine was associated with a higher LM% and lower prevalence of lower LM% in middle-aged and elderly Chinese adults, particularly men.
... Betaine holds an important role in the liver, and has a potential therapeutic use in the treatment of fatty liver disease as well as homocysteinemia, a risk factor for CVD [36,37]. In addition, some studies have demonstrated that betaine supplements improve muscle performance [38]. PC biosynthesis is required for VLDL production, both through the CDPcholine (Kennedy) pathway and the phosphatidylethanolamine N-methyltransferase (PEMT) pathway. ...
Background
Herring roe is an underutilized source of n-3 polyunsaturated fatty acids (PUFAs) for human consumption with high phospholipid (PL) content. Studies have shown that PL may improve bioavailability of n-3 PUFAs. Arctic Nutrition’s herring roe product MOPL™30 is a PL: docosahexaenoic acid (DHA)-rich fish oil mixture, with a DHA:eicosapentaenoic acid (EPA) ratio of about 3:1, which is also rich in choline. In this pilot study, we determined if MOPL30 could favorably affect plasma lipid parameters and glucose tolerance in healthy young adults.
Methods
Twenty female and one male adults, between 22 and 26 years of age, participated in the study. Participants took encapsulated MOPL30, 2.4 g/d EPA + DHA, for 14 days, and completed a three-day weighed food record before and during the capsule intake. Plasma lipids and their fatty acid (FA) composition, plasma and red blood cell (RBC) phosphatidylcholine (PC) FA composition, acylcarnitines, choline, betaine and insulin were measured before and after supplementation (n = 21), and one and four weeks after discontinuation of supplementation (n = 14). An oral glucose tolerance test was performed before and after supplementation.
Results
Fasting plasma triacylglycerol and non-esterified fatty acids decreased and HDL-cholesterol increased after 14 days of MOPL30 intake (p < 0.05). The dietary records showed that PUFA intake prior to and during capsule intake was not different. Fasting plasma glucose was unchanged from before to after supplementation. However, during oral glucose tolerance testing, blood glucose at both 10 and 120 min was significantly lower after supplementation with MOPL30 compared to baseline measurements. Plasma free choline and betaine were increased, and the n-6/n-3 polyunsaturated (PUFA) ratio in plasma and RBC PC were decreased post-supplementation. Four weeks after discontinuation of MOPL30, most parameters had returned to baseline, but a delayed effect was observed on n-6 PUFAs.
Conclusions
Herring roe rich in PL improved the plasma lipid profile and glycemic control in young adults with an overall healthy lifestyle.
The most important pathway in the development of folate-related pathologies is an increase in the level of homocysteine (HC). HC, a cytotoxic and neurotoxic amino acid (when its level is ≥12 μmol/L), is 1 of the most widely studied compounds in cardiology, neurobiology, oncology, and embryology for the last 20 years. Given its toxicity, the processes of endogenous detoxification of HC are of particular interest to medicine. To date, the most studied pathway is that of remethylation (the conversion of HC to methionine), with the participation of B12- and B9-dependent methionine synthase. Less studied is remethylation with the participation of the choline derivatives betaine and betaine-HC-S-methyltransferase (BHMT). Therefore, the aim of this review was to conduct a theoretical analysis of available information regarding the contribution of betaine metabolism, its enzyme, and its genetic polymorphism to folate metabolism disturbances, and the development of folate-related pathologies. This review emphasizes the potential clinical significance of 2 factors that can influence the remethylation reaction of HC: the use of betaine and identifying the BHMT gene variants and their impact on the risk for developing certain folate-related pathologies, and treatment options. Moreover, with a high level of methylation of the BHMT gene and in the presence of its low-function variants (eg, rs3733890), it is necessary to use betaine as an additional methyl donor, especially during folate therapy. More clinical research is needed to identify the effects of the different BHMT gene variants on the individual risk for folate-related pathologies to better assess the clinical significance, the need for genetic testing, and betaine consumption.
In this chapter is presented part of the results of a project of the Greek Ministry of Rural Development and Foods (MRDF). This project aimed at the investigation of the freshwater quality (surface and groundwater) in River Water Basins EL07 and ELO4 located in Sterea Hellas, central Greece. This includes the identification of pollution sources as well as the proposal of measures for protection and restoration of water quality, according to the provisions of Community Directive 2000/60 and national regulations. The water properties discussed in this chapter are pH, electrical conductivity, and the inorganic nitrogen ions nitrite, nitrate, and ammonium. The entire area was divided into 11 catchments from which, for two consecutive years (2017–2018), water samples were taken at specified intervals from rivers, lakes, canals, and wells. These samples were analyzed in situ and in the laboratory, evaluated as to their suitability for drinking and irrigation, according to European Union and national regulations. The values of the parameters studied ranged widely among rivers, lakes, groundwater, and drainage canals, reflecting the various prevailing conditions in the different water sources and the special characteristics of the sampling positions. The median values of all the properties studied are lying within the normal and acceptable levels. However, in some places, extreme values, unacceptable for any use were recorded. The pH was higher in lake water, followed by rivers, canals, and groundwaters; electrical conductivity was found to be higher in river and canal waters, followed by canals and groundwaters; nitrite was higher in groundwaters followed by canals, rivers, and lake waters, while nitrate was higher in groundwaters followed by all other categories, and ammonium was higher in canals, followed by lakes, rivers, and groundwaters.
The sources of contamination on a case-by-case basis appear to be anthropogenic, such as poor agricultural practices and, in particular, unsound management of inputs (fertilizers and pesticides), the dumping into drainage canals of untreated municipal or/and industrial waste, livestock farming (as it was found in the catchments, Sperceios – C1, Kifisos – C5, and Asopos – C6). And there are natural sources, such as seawater intrusion and the chemical composition of the rocks of the study area (especially in the catchments: Sperceios – C1, Amfissa – C4, Messapios-Lilantas – C8, Nireas-Kireas-Voudoros-Kimasi – C9, Kallas – C10). The most significant suggested measurement of water contamination are the tracing of contamination sources to identify their origin (agricultural, livestock, urban, industrial), the implementation of good agricultural practices (especially in applying appropriate irrigation methods that reduce nutrient leaching into the aquifer), and the estimation of the nutrient needs by soil and plant analysis or by using precision agriculture practices, both of which permit the differentiation of the amount of nitrogen fertilizers needs by taking into account the significant variability of the soil properties. Furthermore, suggestions include the continuous monitoring of surface and groundwater through certain environmental indicators (for example nitrate content), and taking protection measures of water drilling and application of their protection zones following the River Basin Management Plans, which propose detailed measures based on the article 4 of the Water Framework Directive 2000/60.
Previous studies evaluating the effects of betaine supplementation on body composition offer contradictory findings. This systematic review and meta-analysis assessed the effects of betaine supplementation on body composition indices (body mass [BM], body mass index [BMI], body fat percentage [BFP], fat mass [FM], fat-free mass [FFM]), and dietary intakes. Studies examining the effects of betaine supplementation on body composition and dietary intakes published up to August 2021 were identified through PubMed, the Cochrane Library, Web of Science, Embase, SCOPUS, and Ovid databases. Betaine supplementation failed to significantly affect BM [(WMD:-0.40 kg, 95% CI:-1.46 to 0.64), p=0.447], BMI [(WMD:-0.05 kg/m 2 , 95% CI:-0.36 to 0.25) , p=0.719], BFP [(WMD: 0.26%, 95% CI:-0.82 to 1.36) , p=0.663], FM [(WMD:-0.57 kg, 95% CI:-2.14 to 0.99) , p=0.473], and FFM [(WMD: 0.61 kg, 95% CI:-1.27 to 2.49), p=0.527]. Subgroup analyses based on participant's age (<40 and >40 years), sex, BMI, trial duration (<8 and ≥8 weeks), betaine supplementation dosage (<4 and ≥4 g), and health status (healthy or unhealthy) demonstrated similar results. Other than a potential negligible increase in protein intake (WMD: 3.56 g, 95% CI: 0.24 to 6.88, p=0.035), no changes in dietary intakes were observed following betaine supplementation compared to control. The present systematic review and meta-analysis does not show any beneficial effects of betaine supplementation on body composition indices (BM, BMI, BFP, FM, and FFM).
Controversy regarding the effects of betaine supplementation on cardiovascular markers has persisted for decades. This systematic review and meta-analysis compared the effects of betaine sup-plementation on cardiovascular disease (CVD) markers. Studies examining betaine supplementation on CVD markers published up to February 2021 were identified through PubMed, the Cochrane Library, Web of Science, Embase, and SCOPUS. Betaine supplementation had a significant effect on concentrations of betaine (MD: 82.14 lmol/L, 95% CI: 67.09 to 97.20), total cholesterol (TC) (MD: 14.12 mg/dl, 95% CI%: 9.23 to 19.02), low-density lipoprotein (LDL) (MD: 10.26 mg/dl, 95% CI: 6.14 to 14.38)], homocysteine (WMD: À1.30 micromol/L, 95% CI: À1.61 to À0.98), dimethylglycine (DMG) (MD: 21.33 micromol/L, 95% CI: 13.87 to 28.80), and methionine (MD: 2.06 micromol/L, 95% CI: 0.23 to 3.88). Moreover, our analysis indicated that betaine supplementation did not affect serum concentrations of triglyceride (TG), high-density lipoprotein (HDL), fasting blood glucose (FBG), C-reactive protein (CRP), liver enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT)], and blood pressure. Our subgroup analysis suggested that a maximum dose of 4 g/d might have homocysteine-lowering effects without any adverse effect on lipid profiles reported with doses of !4 g/d. In conclusion, the present systematic review and meta-analysis supports the advantage of a lower dose of betaine supplementation (<4 g/d) on homocyst-eine concentrations without the lipid-augmenting effect observed with a higher dosage.
PURPOSE: The purpose of this study was to investigate the effect of acute resistance exercise intensity on pain perception, muscle mechanical properties, oxygen saturation (OS) and lactate in taekwondo athletes.METHODS: A total of 21 national and university taekwondo athletes participated in the study. The participants were randomly classified into 70% of one repetition maximum (1 RM) (70% group, n=7), 30% of 1 RM (30% group, n=7), and 30% all-out group of 1 RM (30%A group, n=7). We measured resting pain perception, muscle mechanical properties, lactate, heart rate (HR) and OS, and those were measured immediately after exercise (IAE), 5- and 15-minute after recovery according to exercise intensity.RESULTS: The 70% group showed that heat pain threshold (HPT) became numerically sensitive IAE compared to rest. Pain visual analog scale (VAS) and HR increased significantly IAE compared to rest, and lactate increased significantly IAE, 5- and 15-minute after exercise compared to rest, respectively. Dynamic stiffness (DS) decreased significantly in 15-minute after the exercise compared to IAE. In 30% group case, pain VAS and HR increased significantly IAE compared to rest, and lactate increased significantly IAE, 5- and 15-minute after exercise compared to rest, respectively. DS decreased significantly in 15-minute after the exercise compared to IAE. The 30%A group showed that pain VAS and HR increased significantly IAE compared to rest. Lactate increased significantly IAE, 5-and 15-minute after exercise compared to rest, respectively. DS decreased significantly in immediately and 5-minute after the exercise compared to rest, respectively. Frequency increased IAE compared to rest.CONCLUSIONS: HPT, pain VAS, lactate, HR, and OS were found to be no difference between resistance exercise intensity. The intensity of 1 RM 30% all-out has been shown to contribute to muscle-adaptation effects of resistance exercise by further increasing muscle tension and dynamic stiffness as much as 70% of 1 RM.
Post-exercise carbohydrate repletion of skeletal muscle glycogen utilising maltodextrin, with or without highly digestible protein, can improve performance in humans which has been extrapolated to dogs. There is limited metabolic evidence regarding substrate utilisation during exercise with and without supplementation other than serum hormone status and serum amino acid responses. The objectives of this study were 2-fold; (1) to examine the metabolomic changes associated with a weight-pulling exercise; and (2) to examine the effects of maltodextrin/protein supplementation on serum metabolomics during recovery. Serum was collected from 12 dogs (6 control and 6 treatment) at different time points (pre-exercise, 0 min post-exercise, 30 min post, 3 h post) and liquid chromatography-mass spectrometry (LC-MS) was performed identifying 242 metabolites. A two-way analysis of variance for time and treatment with false discovery rate correction was performed using MetaboAnalyst 3.0. There were 9 metabolites found to be significantly increased or decreased immediately after exercise from baseline representing primarily citric acid cycle metabolites. Treatment differences at 30 min post-exercise showed increases in 8 metabolites including amino acids and carbohydrate intermediates with supplementation. Thirty-seven metabolites were significantly different at 3 h post-exercise, with most metabolites being related to amino acid increases, as well as decreases in fatty acid metabolites with supplementation. Definite alterations in metabolites suggesting that post-exercise supplementation with maltodextrin and protein supports glucose metabolism and alters fatty acid metabolism or clearance during recovery from a weight-pulling exercise.
Studies have established that supplementation of nitrate increases nitrous oxide which in turn improves exercise performance. The current study aimed to investigate the effects of nitrate ingestion on performance of bench press resistance exercise till failure. Twelve recreationally active (age, 21 ± 2yrs, height, 177.2 ± 4.0 cm, weight, 82.49 ± 9.78 kg) resistance trained males participated in the study. The study utilised a double blind randomized cross-over design, where participants ingested either 70 ml of "BEET It Sport ®" nitrate shot containing 6.4 millimoles (mmol/L) or 400 mg of nitrate; or a blackcurrant placebo drink. Participants completed a resistance exercise session, consisting of bench press exercise at an intensity of 60% of their established 1 repetition maximum (1-RM), for three sets until failure with 2 minute rest interval between sets. The repetitions completed, total weight lifted, local and general rate of perceived exertion (RPE), and blood lactate were all measured. The results showed a significant difference in repetitions to failure (p < 0.001) and total weight lifted (p < 0.001). However there were no significant difference between blood lactate over the two trials (p = 0.238), and no difference in Local (p = 0.807) or general (p = 0.420) indicators of fatigue as measured by RPE. This study demonstrates that nitrate supplementation has the potential to improve resistance training performance and work output compared to a placebo.
This chapter characterises betaine and its authorised health claim in respect to dietary sources, scientific substantiation, benefits for consumers, interaction with the EU legislation and safety. The European Commission has authorised a health claim for betaine on the contribution to normal homocysteine metabolism. Betaine is obtained from natural dietary sources and is also allowed in food supplements in the EU, and this is examined from the view of condition of use, e.g. the adequate daily intake of betaine. The aim is to characterise the value of betaine related to benefits and health risks for the general population. A question is raised concerning consumer understanding of the authorised heath claim and especially the word homocysteine.
Betaine has been widely used in animal and human nutrition to promote muscle growth and performance, yet it remains unknown whether maternal betaine supplementation during gestation affects the metabolic characteristics of neonatal skeletal muscles. In the present study, feeding sows with betaine-supplemented diets throughout gestation significantly up-regulated the expression of mtDNA-encoded OXPHOS genes (P<0.05) including COX1, COX2 and ND5, in the muscle of newborn piglets, which was associated with enhanced mitochondrial COX enzyme activity (P<0.05). Concurrently, maternal betaine supplementation increased plasma betaine concentration and muscle expression of methyl transfer enzymes (P<0.05), BHMT and GNMT in offspring piglets. Nevertheless, Dnmt3a was down-regulated at the level of both mRNA and protein, which was associated with hypomethylated mtDNA D-loop region (P<0.05). These results suggest that maternal betaine supplementation during gestation enhances expression of mtDNA-encoded genes through D-loop DNA hypomethylation in skeletal muscle of newborn piglets.
The aim of this study was to investigate the acid-base balance parameters in blood of sportsmen by physical activity. Before exercise lactate concentration in blood was normal. Carbon dioxide pressure (рСО2), bicarbonate concentration (НСО3 -), base excess (BE), were increased immediately after physical activity lactate concentration increased, while pH, BE, НСО3 -, рСО2 decreased in capillary blood of sportsmen. These changes show the development of lactate-acidosis which is partly compensated with bicarbonate buffering system and respiratory alkalosis. During postexercise recovery lactate concentration decreased, while рСО2, НСО3 -, BE increased. The results of this study can be used for diagnostics of acid-base disorders and their medical treatment for preservation of sportsmen physical capacity.
Betaine is distributed widely in animals, plants, and microorganisms, and rich dietary sources include seafood, especially marine invertebrates (≈1%); wheat germ or bran (≈1%); and spinach (≈0.7%). The principal physiologic role of betaine is as an osmolyte and methyl donor (transmethylation). As an osmolyte, betaine protects cells, proteins, and enzymes from environmental stress (eg, low water, high salinity, or extreme temperature). As a methyl donor, betaine participates in the methionine cycle—primarily in the human liver and kidneys. Inadequate dietary intake of methyl groups leads to hypomethylation in many important pathways, including 1) disturbed hepatic protein (methionine) metabolism as determined by elevated plasma homocysteine concentrations and decreased S-adenosylmethionine concentrations, and 2) inadequate hepatic fat metabolism, which leads to steatosis (fatty accumulation) and subsequent plasma dyslipidemia. This alteration in liver metabolism may contribute to various diseases, including coronary, cerebral, hepatic, and vascular diseases. Betaine has been shown to protect internal organs, improve vascular risk factors, and enhance performance. Databases of betaine content in food are being developed for correlation with population health studies. The growing body of evidence shows that betaine is an important nutrient for the prevention of chronic disease.
In the last decade the study of the human brain and muscle energetics underwent a radical change, thanks to the progressive introduction of noninvasive techniques, including near-infrared (NIR) spectroscopy (NIRS). This review summarizes the most recent literature about the principles, techniques, advantages, limitations, and applications of NIRS in exercise physiology and neuroscience. The main NIRS instrumentations and measurable parameters will be reported. NIR light (700-1000 nm) penetrates superficial layers (skin, subcutaneous fat, skull, etc.) and is either absorbed by chromophores (oxy- and deoxyhemoglobin and myoglobin) or scattered within the tissue. NIRS is a noninvasive and relatively low-cost optical technique that is becoming a widely used instrument for measuring tissue O-2 saturation, changes in hemoglobin volume and, indirectly, brain/muscle blood flow and muscle O-2 consumption. Tissue O-2 saturation represents a dynamic balance between O-2 supply and O-2 consumption in the small vessels such as the capillary arteriolar and venular bed. The possibility of measuring the cortical activation in response to different stimuli, and the changes in the cortical cytochrome oxidase redox state upon O-2 delivery changes, will also be mentioned.
We investigated the ergogenic effects of betaine (B) supplementation on strength and power performance.
Twelve men (mean +/- SD age, 21 +/- 3 yr; mass, 79.1 +/- 10.7 kg) with a minimum of 3 months resistance training completed two 14-day experimental trials separated by a 14-day washout period, in a balanced, randomized, double-blind, repeated measures, crossover design. Prior to and following 14 days of twice daily B or placebo (P) supplementation, subjects completed two consecutive days (D1 and D2) of a standardized high intensity strength/power resistance exercise challenge (REC). Performance included bench, squat, and jump tests.
Following 14-days of B supplementation, D1 and D2 bench throw power (1779 +/- 90 and 1788 +/- 34 W, respectively) and isometric bench press force (2922 +/- 297 and 2503 +/- 28 N, respectively) were increased (p < 0.05) during REC compared to pre-supplementation values (1534 +/- 30 and 1498 +/- 29 W, respectively; 2345 +/- 64 and 2423 +/- 84 N, respectively) and corresponding P values (1374 +/- 128 and 1523 +/- 39 W; 2175 +/- 92 and 2128 +/- 56 N, respectively). Compared to pre-supplementation, vertical jump power and isometric squat force increased (p < 0.05) on D1 and D2 following B supplementation. However, there were no differences in jump squat power or the number of bench press or squat repetitions.
B supplementation increased power, force and maintenance of these measures in selected performance measures, and these were more apparent in the smaller upper-body muscle groups.
Intense exercise induces increased blood neutrophil counts and decreased lymphocyte counts, and leads to inflammation and immunosuppression. It was previously reported that cystine and theanine (CT) supplementation by long-distance runners before a training camp suppressed the changes of these blood parameters observed in un-supplemented control subjects after the camp. The purpose of the present study was to determine the effects of CT supplementation on the inflammatory response and immune state before and after intense endurance exercise in long-distance runners at a training camp.
Sixteen long-distance runners were allocated to one of two groups given CT supplements (700 mg cystine + 280 mg theanine daily) or placebo (8 in each group) for 7 days prior to and during a 9-day training camp. Daily run training averaged 19.9 km/day prior to the camp and 28.6 km/day during the camp. On the initial and final days of the camp, blood samples were collected before and after 15 km morning interval running workouts (1000 m x 15 times) and analyzed for neutrophil and lymphocyte counts and myoglobin.
The relative change in exercise-induced blood neutrophil count (% of pre-exercise values) was significantly lower in the CT group than in the placebo group (163.3 +/- 43.2% vs. 200.4 +/- 19.6%, p = 0.044) on the initial day of camp, but not on the last day. The decline in lymphocyte count (% of pre-exercise values) was significantly less in the CT group than in the placebo group (60.2 +/- 19.2% vs. 36.2 +/- 12.0%, p = 0.010) on the initial day of camp, but not on the last day. In blood myoglobin, there was a trend toward lower % of pre-exercise values in the CT group (p < 0.09) on both measurement days.
CT supplementation significantly attenuated the increase in neutrophil count and the reduction in lymphocyte count induced by intense endurance exercise. These results suggest that CT supplementation may suppress the exercise-induced fluctuation of the blood immunocompetent cells and may help to reduce the alteration of the immune state.
Research has indicated that low-to-moderate dosages of caffeine supplementation are ergogenic for sustained endurance efforts as well as high-intensity exercise. The effects of caffeine supplementation on strength-power performance are equivocal, with some studies indicating a benefit and others demonstrating no change in performance. The majority of research that has examined the effects of caffeine supplementation on strength-power performance has been carried out in both trained and untrained men. Therefore, the purpose of this study was to determine the acute effects of caffeine supplementation on strength and muscular endurance in resistance-trained women.
In a randomized manner, 15 women consumed caffeine (6 mg/kg) or placebo (PL) seven days apart. Sixty min following supplementation, participants performed a one-repetition maximum (1RM) barbell bench press test and repetitions to failure at 60% of 1RM. Heart rate (HR) and blood pressure (BP) were assessed at rest, 60 minutes post-consumption, and immediately following completion of repetitions to failure.
Repeated measures ANOVA indicated a significantly greater bench press maximum with caffeine (p </= 0.05) (52.9 +/- 11.1 kg vs. 52.1 +/- 11.7 kg) with no significant differences between conditions in 60% 1RM repetitions (p = 0.81). Systolic blood pressure was significantly greater post-exercise, with caffeine (p < 0.05) (116.8 +/- 5.3 mmHg vs. 112.9 +/- 4.9 mmHg).
These findings indicate a moderate dose of caffeine may be sufficient for enhancing strength performance in resistance-trained women.
We compared Glycine Propionyl-L-Carnitine (GlycoCarn(R)) and three different pre-workout nutritional supplements on measures of skeletal muscle oxygen saturation (StO2), blood nitrate/nitrite (NOx), lactate (HLa), malondialdehyde (MDA), and exercise performance in men.
Using a randomized, double-blind, cross-over design, 19 resistance trained men performed tests of muscular power (bench press throws) and endurance (10 sets of bench press to muscular failure). A placebo, GlycoCarn(R), or one of three dietary supplements (SUPP1, SUPP2, SUPP3) was consumed prior to exercise, with one week separating conditions. Blood was collected before receiving the condition and immediately after exercise. StO2 was measured during the endurance test using Near Infrared Spectroscopy. Heart rate (HR) and rating of perceived exertion (RPE) were determined at the end of each set.
A condition effect was noted for StO2 at the start of exercise (p = 0.02), with GlycoCarn(R) higher than SUPP2. A condition effect was also noted for StO2 at the end of exercise (p = 0.003), with SUPP1 lower than all other conditions. No statistically significant interaction, condition, or time effects were noted for NOx or MDA (p > 0.05); however, MDA decreased 13.7% with GlycoCarn(R) and increased in all other conditions. Only a time effect was noted for HLa (p < 0.0001), with values increasing from pre- to post-exercise. No effects were noted for HR, RPE, or for any exercise performance variables (p > 0.05); however, GlycoCarn(R) resulted in a statistically insignificant greater total volume load compared to the placebo (3.3%), SUPP1 (4.2%), SUPP2 (2.5%), and SUPP3 (4.6%).
None of the products tested resulted in favorable changes in our chosen outcome measures, with the exception of GlycoCarn(R) in terms of higher StO2 at the start of exercise. GlycoCarn(R) resulted in a 13.7% decrease in MDA from pre- to post-exercise and yielded a non-significant but greater total volume load compared to all other conditions. These data indicate that 1) a single ingredient (GlycoCarn(R)) can provide similar practical benefit than finished products containing multiple ingredients, and 2) while we do not have data in relation to post-exercise recovery parameters, the tested products are ineffective in terms of increasing blood flow and improving acute upper body exercise performance.
The purpose of this study was to examine the effect of a commercially available energy drink on time to exhaustion during treadmill exercise. In addition, subjective measures of energy, focus, and fatigue were examined
Fifteen subjects (9 men and 6 women; 20.9 +/- 1.0 y; 172.1 +/- 9.1 cm; 71.0 +/- 9.4 kg; 16.9 +/- 9.7% body fat) underwent two testing sessions administered in a randomized, double-blind fashion. Subjects reported to the laboratory in a 3-hr post-absorptive state and were provided either the supplement (SUP; commercially marketed as Amino Impact) or placebo (P). During each laboratory visit subjects performed a treadmill run (70% VO2 max) to exhaustion. Mean VO2 was measured during each endurance exercise protocol. Subjects were required to complete visual analog scales for subjective measures of energy, focus and fatigue at the onset of exercise (PRE), 10-mins into their run (EX10) and immediately post-exercise (IP).
Time to exhaustion was significantly greater (p = 0.012) during SUP than P. Subjects consuming the supplement were able to run 12.5% longer than during the placebo treatment. Subjects consuming SUP reported significantly greater focus (p = 0.031), energy (p = 0.016), and less fatigue (p = 0.005) at PRE. Significant differences between groups were seen at EX10 for focus (p = 0.026) and energy (p = 0.004), but not fatigue (p = 0.123). No differences were seen at IP for either focus (p = 0.215), energy (p = 0.717) or fatigue (p = 0.430).
Results of this study indicate that the supplement Amino Impact can significantly increase time to exhaustion during a moderate intensity endurance run and improve subjective feelings of focus, energy and fatigue.
Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients.
The purpose of this study was to examine the efficacy of 15 days of betaine supplementation on muscle endurance, power performance and rate of fatigue in active college-aged men.
Twenty-four male subjects were randomly assigned to one of two groups. The first group (BET; 20.4 +/- 1.3 years; height: 176.8 +/- 6.6 cm; body mass: 77.8 +/- 13.4 kg) consumed the supplement daily, and the second group (PL; 21.4 +/- 4.7 years; height: 181.3 +/- 5.9 cm; body mass: 83.3 +/- 5.2 kg) consumed a placebo. Subjects were tested prior to the onset of supplementation (T1) and 7 (T2) and 14 days (T3) following supplementation. Each testing period occurred over a 2-day period. During day one of testing subjects performed a vertical jump power (VJP) and a bench press throw (BPT) power test. In addition, subjects were required to perform as many repetitions as possible with 75% of their 1-RM in both the squat and bench press exercises. Both peak and mean power was assessed on each repetition. On day two of testing subjects performed two 30-sec Wingate anaerobic power tests (WAnT), each test separated by a 5-min active rest.
No differences were seen at T2 or T3 in the repetitions performed to exhaustion or in the number of repetitions performed at 90% of both peak and mean power between the groups in the bench press exercise. The number of repetitions performed in the squat exercise for BET was significantly greater (p < 0.05) than that seen for PL at T2. The number of repetitions performed at 90% or greater of peak power in the squat exercise was significantly greater for BET at both T2 and T3 than PL. No differences in any power assessment (VJP, BPT, WAnT) was seen between the groups
Two-weeks of betaine supplementation in active, college males appeared to improve muscle endurance of the squat exercise, and increase the quality of repetitions performed.
We examined the influence of L-carnitine L-tartrate (LCLT) on markers of purine catabolism, free radical formation, and muscle tissue disruption after squat exercise. With the use of a balanced, crossover design (1 wk washout), 10 resistance-trained men consumed a placebo or LCLT supplement (2 g L-carnitine/day) for 3 wk before obtaining blood samples on six consecutive days (D1 to D6). Blood was also sampled before and after a squat protocol (5 sets, 15-20 repetitions) on D2. Muscle tissue disruption at the midthigh was assessed using magnetic resonance imaging (MRI) before exercise and on D3 and D6. Exercise-induced increases in plasma markers of purine catabolism (hypoxanthine, xanthine oxidase, and serum uric acid) and circulating cytosolic proteins (myoglobin, fatty acid-binding protein, and creatine kinase) were significantly (P < or = 0.05) attenuated by LCLT. Exercise-induced increases in plasma malondialdehyde returned to resting values sooner during LCLT compared with placebo. The amount of muscle disruption from MRI scans during LCLT was 41-45% of the placebo area. These data indicate that LCLT supplementation is effective in assisting recovery from high-repetition squat exercise.
Betaine is distributed widely in animals, plants, and microorganisms, and rich dietary sources include seafood, especially marine invertebrates ( approximately 1%); wheat germ or bran ( approximately 1%); and spinach ( approximately 0.7%). The principal physiologic role of betaine is as an osmolyte and methyl donor (transmethylation). As an osmolyte, betaine protects cells, proteins, and enzymes from environmental stress (eg, low water, high salinity, or extreme temperature). As a methyl donor, betaine participates in the methionine cycle-primarily in the human liver and kidneys. Inadequate dietary intake of methyl groups leads to hypomethylation in many important pathways, including 1) disturbed hepatic protein (methionine) metabolism as determined by elevated plasma homocysteine concentrations and decreased S-adenosylmethionine concentrations, and 2) inadequate hepatic fat metabolism, which leads to steatosis (fatty accumulation) and subsequent plasma dyslipidemia. This alteration in liver metabolism may contribute to various diseases, including coronary, cerebral, hepatic, and vascular diseases. Betaine has been shown to protect internal organs, improve vascular risk factors, and enhance performance. Databases of betaine content in food are being developed for correlation with population health studies. The growing body of evidence shows that betaine is an important nutrient for the prevention of chronic disease.
In the last decade the study of the human brain and muscle energetics underwent a radical change, thanks to the progressive introduction of noninvasive techniques, including near-infrared (NIR) spectroscopy (NIRS). This review summarizes the most recent literature about the principles, techniques, advantages, limitations, and applications of NIRS in exercise physiology and neuroscience. The main NIRS instrumentations and measurable parameters will be reported. NIR light (700-1000 m) penetrates superficial layers (skin, subcutaneous fat, skull, etc.) and is either absorbed by chromophores (oxy- and deoxyhemoglobin and myoglobin) or scattered within the tissue. NIRS is a noninvasive and relatively low-cost optical technique that is becoming a widely used instrument for measuring tissue O2 saturation, changes in hemoglobin volume and, indirectly, brain/muscle blood flow and muscle O2 consumption. Tissue O2 saturation represents a dynamic balance between O2 supply and O2 consumption in the small vessels such as the capillary, arteriolar, and venular bed. The possibility of measuring the cortical activation in response to different stimuli, and the changes in the cortical cytochrome oxidase redox state upon O2 delivery changes, will also be mentioned.
To interpret or to predict the responses of biopolymer processes in vivo and in vitro to changes in solute concentration and to coupled changes in water activity (osmotic stress), a quantitative understanding of the thermodynamic consequences of interactions of solutes and water with biopolymer surfaces is required. To this end, we report isoosmolal preferential interaction coefficients (Gamma(mu1) determined by vapor pressure osmometry (VPO) over a wide range of concentrations for interactions between native bovine serum albumin (BSA) and six small solutes. These include Escherichia coli cytoplasmic osmolytes [potassium glutamate (K(+)Glu(-)), trehalose], E. coli osmoprotectants (proline, glycine betaine), and also glycerol and trimethylamine N-oxide (TMAO). For all six solutes, Gamma(mu1) and the corresponding dialysis preferential interaction coefficient Gamma(mu1),(mu3) (both calculated from the VPO data) are negative; Gamma(mu1), (mu3) is proportional to bulk solute molality (m(bulk)3) at least up to 1 m (molal). Negative values of Gamma(mu1),(mu3) indicate preferential exclusion of these solutes from a BSA solution at dialysis equilibrium and correspond to local concentrations of these solutes in the vicinity of BSA which are lower than their bulk concentrations. Of the solutes investigated, betaine is the most excluded (Gamma(mu1),(mu3)/m(bulk)3 = -49 +/- 1 m(-1)); glycerol is the least excluded (Gamma(mu1),(mu3)/m(bulk)3 = -10 +/- 1 m(-1)). Between these extremes, the magnitude of Gamma(mu1),(mu3)/m(bulk)3 decreases in the order glycine betaine > proline >TMAO > trehalose approximately K(+)Glu(-) > glycerol. The order of exclusion of E. coli osmolytes from BSA surface correlates with their effectiveness as osmoprotectants, which increase the growth rate of E. coli at high external osmolality. For the most excluded solute (betaine), Gamma(mu1),(mu3) provides a minimum estimate of the hydration of native BSA of approximately 2.8 x 10(3) H(2)O/BSA, which corresponds to slightly less than a monolayer (estimated to be approximately 3.2 x 10(3) H(2)O). Consequently, of the solutes investigated here, only betaine might be suitable for use in osmotic stress experiments in vitro as a direct probe to quantify changes in hydration of protein surface in biopolymer processes. More generally, however, our results and analysis lead to the proposal that any of these solutes can be used to quantify changes in water-accessible surface area (ASA) in biopolymer processes once preferential interactions of the solute with biopolymer surface are properly taken into account.
This study examined the effects of 26 days of oral creatine monohydrate (Cr) supplementation on near-maximal muscular strength, high-intensity bench press performance, and body composition. Eighteen male powerlifters with at least 2 years resistance training experience took part in this 28-day experiment. Pre and postmeasurements (Days 1 and 28) were taken of near-maximal muscular strength, body mass, and % body fat. There were two periods of supplementation: Days 2 to 6 and Days 7 to 27. ANOVA and t-tests revealed that Cr supplementation significantly increased body mass and lean body mass with no changes in % body fat. Significant increases in 3-RM strength occurred in both groups, both absolute and relative to body mass; the increases were greater in the Cr group. The change in total repetitions also increased significantly with Cr supplementation both in absolute terms and relative to body mass, while no significant change was seen in the placebo (P) group. Creatine supplementation caused significant changes in the number of BP reps in Sets 1, 4, and 5. No changes occurred in the P group. It appears that 26 days of Cr supplementation significantly improves muscular strength and repeated near-maximal BP performance, and induces changes in body composition.
NITRIC OXIDE-STIMULATING DIETARY SUPPLEMENTS ARE ARGUABLY THE MOST WIDELY ADVERTIZED AND PROMOTED AGENTS IN THE SPORT/BODYBUILDING NUTRITION ARENA TODAY. UNFORTUNATELY, THESE PRODUCTS HAVE LITTLE SCIENTIFIC EVIDENCE FOR EFFECT, DESPITE THE MASSIVE HYPE THAT SURROUNDS THE AGGRESSIVE ADVERTISING CAMPAIGNS. WHILE SOME ANECDOTAL REPORTS SUGGEST A POTENTIAL BENEFIT FROM USING THESE PRODUCTS, ONE CANNOT RULE OUT THE POSSIBILITY OF A “PLACEBO EFFECT.” THE PURPOSE OF THIS REVIEW IS TO PRESENT INFORMATION RELATED TO THE ROLE OF NITRIC OXIDE IN SPORT PERFORMANCE AND TO PROVIDE AN OVERVIEW OF THE SCIENTIFIC RATIONALE FOR THE USE OF NUTRITIONAL SUPPLEMENTS AIMED AT INCREASING NITRIC OXIDE.
Betaine is an essential osmolyte and source of methyl groups and comes from either the diet or by the oxidation of choline. Its metabolism methylates homocysteine to methionine, also producing N,N-dimethylglycine. Betaine insufficiency is associated with the metabolic syndrome, lipid disorders and diabetes, and may have a role in vascular and other diseases. Betaine is important in development, from the pre-implantation embryo to infancy. Betaine supplementation improves animal and poultry health, but the effect of long-term supplementation on humans is not known, though reports that it improves athletic performance will stimulate further studies. Subsets of the population that may benefit from betaine supplementation could be identified by the laboratory, in particular those who excessively lose betaine through the urine.Plasma betaine is highly individual, in women typically 20–60 μmol/L and in men 25–75 μmol/L. Plasma dimethylglycine is typically < 10 μmol/L. Urine betaine excretion is minimal, even following a large betaine dose. It is constant, highly individual and normally < 35 mmol/mole creatinine. The preferred method of betaine measurement is by LC-MS/MS, which is rapid and capable of automation. Slower HPLC methods give comparable results. Proton NMR spectrometry is another option but caution is needed to avoid confusion with trimethylamine-N-oxide.
1. Basal release of nitric oxide from the vascular endothelium maintains a constant vasodilating tone. Impaired nitric oxide-mediated vasodilatation has been described in hypertension and atheromatous disease. Circulatory diseases account for considerable morbidity and almost half of all deaths in people over the age of 75 years.
2. We have therefore compared nitric oxide-dependent vasorelaxation in 12 healthy elderly subjects with 12 young volunteers matched for blood pressure, cholesterol and glucose, using forearm occlusion venous plethysmography combined with brachial artery infusions of the nitric oxide synthase inhibitor, NG-monomethyl-l-arginine (l-NMMA; 1, 2 and 4 μmol/min) with noradrenaline (60, 120 and 240 pmol/min) as a control vasoconstrictor. We also measured urinary nitrate excretion after a controlled 48 h low nitrate diet as an index of total body nitric oxide production and correlated these changes with forearm blood flow responses to l-NMMA and noradrenaline in both groups.
3. The mean age and blood pressure of the elderly subjects was 76 (range 66–82) years and 132/76 (SEM 4/3) mmHg respectively, while in the young these were 27 (20–35) years and 131/72 (4/3) mmHg respectively. l-NMMA and noradrenaline produced dose-dependent reductions in forearm blood flow in both groups. l-NMMA (4 μmol/min) produced less vasoconstriction in the elderly than in the young (−37.7 ± 2.6 versus −48.3 ± 4.2%; P = 0.017). The mean slope of the l-NMMA dose-response curves in the elderly was significantly less than the younger group (−35.2 ± 3.1 versus −63.7 ± 10.6; P = 0.041). Noradrenaline, 240 pmol/min, also produced less vasoconstriction in the elderly compared with the young (−22.8 ± 2.9 versus −35.3 ± 5.0%; P = 0.029) although the slopes of the dose—response curves did not differ significantly.
4. Urinary nitrate adjusted for creatinine clearance was also significantly higher in the younger group (460.6 ± 97.7 versus 205.9 ± 64.8 μmol/day; P = 0.042) and showed a significant correlation with the percentage change in forearm blood flow in response to the maximum dose of l-NMMA (r = 0.5, P = 0.046).
5. We conclude that nitric oxide-mediated vasodilatation in the forearm vascular bed is diminished in old age and this reflects a more generalized reduction in nitric oxide production (as measured by urinary nitrate) in the circulation of older people. The blunted response to noradrenaline points to a more generalized reduction in vascular reactivity in the elderly.
Nitric oxide dietary supplements are extremely popular within the sport and bodybuilding community. Most products contain l-arginine, for which there is no direct evidence that oral L-arginine increases circulating nitric oxide or blood flow. A new molecule (2-[nitrooxy]thyl 2-amino-3-methylbutanoate) is being marketed as a sport supplement for purposes of delivering "real nitric oxide" to the circulation. In the present study, we measured the acute effects of this supplement on blood nitrate/nitrite and hemodynamic variables. Ten resistance trained men (26 ± 4 years old; 8 ± 6 years of resistance exercise training) reported to the laboratory in random order after a 10-hour overnight fast on 2 occasions separated by 1 week and were provided the supplement (2-[nitrooxy]ethyl 2-amino-3-methylbutanoate) or placebo. Heart rate and blood pressure were recorded, and venous blood samples were collected before and at 5, 15, 30, and 60 minutes after complete breakdown of the supplement (5 minutes post intake) or placebo. Blood samples were assayed for plasma nitrate/nitrite. No interaction (p = 0.99), condition (p = 0.18), or time (p = 0.98) effects were noted for plasma nitrate/nitrite, with values remaining nearly identical across time for placebo (∼27 μmol·L(-1)) and increasing a maximum of ∼6.7% (from 32.9 to 35.1 μmol·L(-1)) at the 15-minute collection period for the supplement. In regards to hemodynamic variables, no interaction, condition, or time effects were noted for heart rate, systolic, or diastolic blood pressure (p > 0.05), with values near identical between conditions and virtually unchanged across time. These findings indicate that 2-(nitrooxy)ethyl 2-amino-3-methylbutanoate has a small effect on increasing circulating nitrate/nitrite and does not cause any change in hemodynamic variables within the 1 hour postingestion period in a sample of resistance trained men.
Maximal steady state (MSS) speed can be determined from blood lactate concentration (HLa); however, this method is not optimal. The purpose of this study was to determine whether near-infrared spectroscopy (NIRS) technology could be used to detect a breakpoint in percent oxygen saturation (StO2) of the muscle and whether the determined breakpoint exercise intensity could be used to determine MSS exercise intensity. Sixteen distance runners and triathletes (men = 9, VO2max = 64.9 +/- 4.9 ml x kg(-1) x min(-1), women = 7, VO2max = 50.8 +/- 7.0 ml x kg(-1) x min(-1)) completed an incremental exercise test. A change from linearity when plotting StO2 or HLa vs. running speed was defined as the breakpoint. The subjects then completed constant speed runs to determine maximal lactate steady state (MLSS). In 12 subjects, breakpoints were identified for both HLa and StO2 values. Predicted MLSS velocities from HLa breakpoint (12.76 +/- 1.63 km x h(-1)), StO2 breakpoint (12.84 +/- 1.58 km x h(-1)), and 4 mM HLa (13.49 +/- 1.71 km x h(-1)) methods from the incremental test did not differ from MLSS speeds (13.04 +/- 2.03 km x h(-1)). A Bland and Altman analysis of agreement between the MLSS and the StO2 breakpoint speeds resulted in a mean difference of 0.14 +/- 0.36, whereas the mean difference between MLSS and HLa breakpoint speeds was 0.19 +/- 0.43. During the incremental test, no StO2 breakpoint was determined in 2 subjects, whereas 2 subjects had no HLa breakpoint. The results of this study lead us to conclude that the NIRS determination of StO2 is a noninvasive technique that is comparable with HLa in determining MSS intensity and therefore appropriate for use in determining exercise training intensity.
Research suggests that caffeine may improve performance in aerobic exercise; the evidence for anaerobic performance is mixed. This study examined the effect of caffeine (5 mg/kg body weight [BW]) vs. placebo on performance-based anaerobic exercise tests used during the National Football League (NFL) Combine. Collegiate football athletes (n = 17; 20 +/- 2 yr; body mass index 29.4 +/- 3.6 kg/m) completed 2 study visits, 1 week apart. Participants were low caffeine users with a reported average intake of 16 +/- 20 mg/day. On the day of testing, participants ingested a caffeinated (5 mg/kg BW caffeine + 0.125 g/kg BW carbohydrate) or placebo (0.125 g/kg BW carbohydrate) beverage, ate a light meal, and completed 3 exercise tests (40-yard dash, 20-yard shuttle, and a bench press) 60 minutes later. Borg's rating of perceived exertion (RPE) was recorded after each exercise test. Heart rate (HR) and blood pressure (BP) were monitored (pre-exercise and postexercise). Data were analyzed using paired t-tests, Wilcoxon signed rank test, and repeated measures analysis of variance. No significant differences were found between treatments for the exercise tests (40-yard dash: 5.01 +/- 0.25 vs. 5.03 +/- 0.26 s, p = 0.43; 20-yard shuttle: 4.64 +/- 0.19 vs. 4.66 +/- 0.24 s, p = 0.51; bench press: 17 +/- 8 vs. 17 +/- 8 reps, p = 0.51; caffeine vs. placebo, respectively). However, 59% of the participants improved in performance with the caffeine during the bench press and the 40-yard dash. No differences were found between treatments for RPE, HR, and BP. Caffeine did not improve performance for anaerobic exercise tests used at the NFL Combine in caffeine naïve male football athletes.
Previous investigations have demonstrated leg strength deficits in persons with Parkinson's disease (PD) as compared to neurologically-normal adults. However, the exact mode of contraction by which strength is assessed may determine how closely such deficits are related to functional performance. The purpose of this study was to better understand the relationship of strength and functional mobility in persons with PD (n = 17, mean H&Y stage = 2.0) via comparison to a group of similar age healthy controls (n = 10) using a multi-joint isometric test of strength and various measures of functional mobility. Tests included isometric leg press maximum force relative to body mass, the Activities-specific Balance Confidence scale (ABC), postural sway under various unilateral stance and visual conditions, and the timed up and go (TUG). Relative force (p = 0.044) and ABC questionnaire mean scores (p < 0.001), showed controls performing better than PD subjects. The control group performed better than the PD group for length of path of the center of pressure except in the eyes closed positions (p < 0.05 for all). TUG time (p = 0.052) was not significantly different between the PD group and healthy controls. Leg press maximum force relative to body mass was however significantly correlated with TUG time (r = -0.68, p = 0.003) in persons with PD. There were no gender differences for any variables. These results suggest that some balance and functional mobility task performances are more worse for persons with mild-to-moderate PD than for neurologically-normal age-matched controls, which may be influenced by lessened lower extremity multi-joint strength. Strength training of the lower extremity utilizing such multi-joint actions may be beneficial for this population.
The purpose of this study was to examine the effect of 30 days of beta-alanine supplementation in collegiate football players on anaerobic performance measures. Subjects were randomly divided into a supplement (beta-alanine group [BA], 4.5 g x d(-1) of beta-alanine) or placebo (placebo group [P], 4.5 g x d(-1) of maltodextrin) group. Supplementation began 3 weeks before preseason football training camp and continued for an additional 9 days during camp. Performance measures included a 60-second Wingate anaerobic power test and 3 line drills (200-yd shuttle runs with a 2-minute rest between sprints) assessed on day 1 of training camp. Training logs recorded resistance training volumes, and subjects completed questionnaires on subjective feelings of soreness, fatigue, and practice intensity. No difference was seen in fatigue rate in the line drill, but a trend (P = .07) was observed for a lower fatigue rate for BA compared with P during the Wingate anaerobic power test. A significantly higher training volume was seen for BA in the bench press exercise, and a trend (P = .09) for a greater training volume was seen for all resistance exercise sessions. In addition, subjective feelings of fatigue were significantly lower for BA than P. In conclusion, despite a trend toward lower fatigue rates during 60 seconds of maximal exercise, 3 weeks of beta-alanine supplementation did not result in significant improvements in fatigue rates during high-intensity anaerobic exercise. However, higher training volumes and lower subjective feelings of fatigue in BA indicated that as duration of supplementation continued, the efficacy of beta-alanine supplementation in highly trained athletes became apparent.
The widely used TBA assay for lipid peroxidation was modified to minimize artefactual oxidative degradation of lipids during the assay. Formation of the TBA-MDA condensation product was studied with and without exclusion of oxygen, and the concentration effect of BHT addition was examined. Oxygen was depleted from the reaction mixture by extensive argon gassing. Exclusion of oxygen resulted in decreased TBARS production in plasma but not in standard solutions. High BHT concentrations resulted in a similar effect. At concentrations higher than 3 mmol/l BHT exclusion of oxygen had no additional effect. By measuring n-butanol extracts in a multititer plate reader this modified method was made suitable as a preliminary screening assay of human body fluids for lipid peroxidation.
This study was undertaken to investigate the influence of oral supplementation with creatine monohydrate on muscular performance during repeated sets of high-intensity resistance exercise.
Fourteen active men were randomly assigned in a double-blind fashion to either a creatine group (n = 7) or a placebo group (n = 7). Both groups performed a bench press exercise protocol (5 sets to failure using each subject's predetermined 10-repetition maximum) and a jump squat exercise protocol (5 sets of 10 repetitions using 30% of each subject's 1-repetition maximum squat) on three different occasions (T1, T2, and T3) separated by 6 days.
Before T1, both groups received no supplementation. From T1 to T2, both groups ingested placebo capsules. From T2 to T3, the creatine group ingested 25 g creatine monohydrate per day, and the placebo group ingested an equivalent amount of placebo.
Total repetitions for each set of bench presses and peak power output for each set of jump squats were determined. Other measures included assessment of diet, body mass, skinfold thickness, and preexercise and 5-minute postexercise lactate concentrations.
Lifting performance was not altered for either exercise protocol after ingestion of the placebos. Creatine supplementation resulted in a significant improvement in peak power output during all 5 sets of jump squats and a significant improvement in repetitions during all 5 sets of bench presses. After creatine supplementation, postexercise lactate concentrations were significantly higher after the bench press but not the jump squat. A significant increase in body mass of 1.4 kg (range = 0.0 to 2.7 kg) was observed after creatine ingestion.
One week of creatine supplementation (25 g/day) enhances muscular performance during repeated sets of bench press and jump squat exercise.
High plasma homocysteine is a risk for cardiovascular disease and can be lowered through supplementation with 6 g/d of betaine. However, dietary intake of betaine is approximately 0.5-2 g/d. Therefore, we investigated whether betaine supplementation in the range of dietary intake lowers plasma homocysteine concentrations in healthy adults. Four groups of 19 healthy subjects ingested three doses of betaine or placebo daily for 6 wk. A methionine loading test was performed during run in, on d 1 of betaine supplementation, and after 2 and 6 wk of betaine supplementation. Fasting plasma homocysteine after 6-wk daily intakes of 1.5, 3 and 6 g of betaine was 12% (P < 0.01), 15% (P < 0.002) and 20% (P < 0.0001) less than in the placebo group, respectively. Furthermore, the increase in plasma homocysteine after methionine loading on the 1st d of betaine supplementation was 16% (P < 0.06), 23% (P < 0.008) and 35% (P < 0.0002) less than in the placebo group, respectively, and after 6 wk of supplementation was 23% (P < 0.02), 30% (P < 0.003) and 40% (P < 0.0002) less, respectively. Thus, doses of betaine in the range of dietary intake reduce fasting and postmethionine loading plasma homocysteine concentrations. A betaine-rich diet might therefore lower cardiovascular disease risk.
Cordyceps sinensis (Cs) and Rhodiola rosea (Rr) are herbs used in traditional Chinese medicine to treat a multitude of ailments as well as to enhance performance. The purpose of this research was to examine the effects of a formula containing Cs and Rr (Cs-Rr) on circulatory dynamics, specifically muscle tissue oxygen saturation (Sto(2)), in male subjects during maximal exercise. This study followed a double blind, randomized, placebo-treatment, pre-post test design. Capsules were administered to 8 subjects who were randomly assigned to 1 of 2 groups. The treatment group received Cs-Rr, and the control group received a placebo. All subjects performed 2 exercise stress tests to volitional fatigue on a cycle load ergometer. There were no significant (p </= 0.05) differences in Sto(2) slope, Sto(2) threshold (Sto(2T)), Vo(2)max, ventilatory threshold (V(T)), or time to exhaustion (T(E)) between or within the treatment or control group. In conclusion, Cs-Rr did not significantly enhance Sto(2).
Osmotic stress restricts glycolytic flux, growth (rate and yield), D-lactate productivity, and D-lactate tolerance in Escherichia coli B strain SZ132 during batch fermentation in mineral salts medium with 10% (w/v) sugar. Addition of 1 mM: betaine, a non-metabolized protective osmolyte, doubled cell yield, increased specific productivity of D-lactate and glycolytic flux by 50%, and tripled volumetric productivity (from 8.6 to 25.7 mmol l(-1) h(-1); 0.8 to 2.3 g l(-1) h(-1)). Glycolytic flux and specific productivity in mineral salts medium with betaine exceeded that in Luria broth, substantially eliminating the need for complex nutrients during D-lactate production. In mineral salts medium supplemented with betaine, SZ132 produced approximately 1 mol D-lactate (90 g) per 100 g sugar (glucose or sucrose).
Exposure of C2C12 muscle cells to hypertonic stress induced an increase in cell content of creatine transporter mRNA and of creatine transport activity, which peaked after about 24 h incubation at 0.45 osmol (kg H(2)O)(-1). This induction of transport activity was prevented by addition of either cycloheximide, to inhibit protein synthesis, or of actinomycin D, to inhibit RNA synthesis. Creatine uptake by these cells is largely Na(+) dependent and kinetic analysis revealed that its increase under hypertonic conditions resulted from an increase in V(max) of the Na(+)-dependent component, with no significant change in the K(m) value of about 75 mumol l(-1). Quantitative real-time PCR revealed a more than threefold increase in the expression of creatine transporter mRNA in cells exposed to hypertonicity. Creatine supplementation significantly enhanced survival of C2C12 cells incubated under hypertonic conditions and its effect was similar to that obtained with the well known compatible osmolytes, betaine, taurine and myo-inositol. This effect seemed not to be linked to the energy status of the C2C12 cells because hypertonic incubation caused a decrease in their ATP content, with or without the addition of creatine at 20 mmol l(-1) to the medium. This induction of creatine transport activity by hypertonicity is not confined to muscle cells: a similar induction was shown in porcine endothelial cells.
Ageing is associated with an increase in atherothrombotic disease. Platelet-derived nitric oxide (NO) inhibits platelet activation, but the effect of age on platelet NO signaling is unknown. We investigated platelet NO biosynthesis and responsiveness in older (> 45 years old) as compared with younger (< 30 years old) healthy human subjects.
Platelet NO synthase (NOS) activity was evaluated by l-[3H]-arginine to l-[3H]-citrulline conversion, and cGMP was determined by radioimmunoassay. Platelet expression of NOS3, phosphoserine-1177-NOS3 and soluble guanylyl cyclase (sGC) were quantified by Western blotting. Circulating monocyte-platelet aggregates (MPA) were measured by flow cytometry.
Basal NOS activity was similar in both groups. By contrast, whereas both albuterol and collagen stimulated platelet NOS in younger subjects, stimulation was absent in older subjects. Platelet NOS3 expression was similar in both age groups, but NOS3 serine-1177 phosphorylation was greater in younger subjects. Basal, albuterol- and collagen-stimulated cGMP, as well as sGC expression, were all greater in younger than older subjects, and within the younger group both cGMP (basal and stimulated) and sGC expression were greater in women than in men. Circulating MPA were greater in older subjects and, whilst NOS inhibition increased MPA further in both groups, it did so to a lesser extent in the older age bracket.
These data suggest that platelet NO production and responsiveness decrease with age, and this is reflected in increased circulating MPA.
The aim of the present study was to determine the relationship between plasma levels of nitrite/nitrite (NO x ) and brachial flow‐mediated dilation (FMD) in healthy young men and women.
Brachial artery FMD was assessed non‐invasively using high‐resolution ultrasound in 36 young men and women (21 ± 3 years; 18 men and 18 women). Blood samples for NO x assays were collected from an indwelling venous catheter in the forearm following an overnight fast and a 36 h low‐nitrate diet.
Plasma levels of NO x were related to peak brachial FMD% ( r = 0.53; P = 0.001). The relationship was maintained when the brachial dilation was expressed as absolute diameter change (Δmm; r = 0.51; P = 0.002) and when it was normalized (/s) to the mean shear rate ( r = 0.50; P = 0.002).
The present study demonstrates a relationship between peak FMD in the brachial artery and plasma levels of NO x in young men and women. This relationship suggests that brachial FMD and/or plasma NO x may be used as markers of peripheral endothelial function.
Previous research has demonstrated that prior exercise may reduce the magnitude of muscle soreness and impaired function (i.e., repeated bout effect [RBE]) observed during subsequent eccentric exercise. Previous investigations have predominantly used research designs that include single-joint exercise performed by untrained individuals. It is unknown how resistance trained individuals respond to novel multi-joint eccentric actions of the upper body and whether prior exercise offers protection. Thirty-one resistance trained men (23.4 +/- 3.5 y, 177.2 +/- 5.1 cm, 86.4 +/- 16.5 kg, mean +/- SD) were randomly assigned to repeated bout ([RB] N = 15) or single bout ([CON] N = 16) conditions. Both groups performed 100 eccentric actions of the bench press ([ECC] at 70% concentric 1 repetition maximum) to induce muscle injury. Bilateral maximal isometric force, dynamic exercise performance (e.g., bench press throws), and muscle soreness were measured before, immediately after, and at 24 and 48 hours post-ECC. Total work, percent fatigue, and rating of perceived exertion (ECC) data were collected during ECC. Those assigned to RB condition exhibited less fatigue (9.5 vs. 22.6%) and lower RPE (14.8 vs. 17.1) during ECC. A significant interaction (p < 0.05) was found such that RB individuals experienced less soreness at 24 (6.5 vs. 4.9) and 48 (6.6 vs. 3.9) hours postexercise than the CON condition. No significant group differences (p < 0.05) were found for any measured performance variable. Although soreness, fatigue, and RPE suggest a RBE, this was not found in regards to exercise performance. It appears that in trained men, performing a strenuous high-volume eccentric exercise bout 2 weeks prior to an identical future bout offers no additional amelioration of impaired exercise performance.
This investigation evaluated the effects of a nutritional supplement (the organic osmolyte betaine) in rehydration solutions, with and without carbohydrate and electrolytes. Ten male runners ((mean +/- SD) age, 20 +/- 2 years; weight, 70.6 +/- 6.8 kg; maximal aerobic power, 63.5 +/- 4.1 mL O2 x kg(-1) x min(-1)) dehydrated to -2.7% of body weight. They next rehydrated to -1.4% of body weight by consuming 1 L fluid during each of four experiments (double-blind, randomized, cross-over design): flavored, non-caloric water (W); W + 5 g x L(-1) betaine (W+B); 6% carbohydrate-electrolyte fluid (C); or C + 5 g x L(-1) betaine (C+B). Subjects then performed prolonged treadmill running (75 minutes at 65%Vo2max) plus a performance sprint to volitional exhaustion (3.1-3.8 minutes at 84%Vo2max) in an environmental chamber (31.1 degrees C, 88.0 degrees F). Only W versus W+B and C versus C+B statistical comparisons were germane to the research questions. Observations indicated that rehydration with fluids containing betaine resulted in significant differences (p < 0.05) of plasma volume, oxygen consumption, plasma lactate concentration, and thermal sensation. The present experiments did not support the use of betaine to improve sprint duration, but nonsignificant trends occurred when betaine trials were compared with non-betaine trials (mean C+B > C by 32 seconds, +16%; mean W+B > W by 38 seconds, +21%). We interpret the increases of both aerobic and anaerobic metabolism (C+B > C) to mean that further investigation of betaine as a nutritional supplement, using other types of exercise, is warranted.
We have demonstrated previously that urea inhibits the activity and alters the tertiary structure of skeletal muscle myosin in a biphasic manner. This was attributed to differential effects on its globular and filamentous portion. The inhibition of catalytic activity was counteracted by methylamines. With the aim of comprehending the effects of urea on the catalytic (globular) portion of myosin, this study examines the effects of urea and the countereffects of betaine on the catalytic activity and structure of myosin subfragment-1. It is shown that urea inactivates subfragment-1 in parallel with its ability to induce exposure of the enzyme hydrophobic domains, as assessed using intrinsic and extrinsic fluorescence. Both effects are counteracted by betaine, which alone does not significantly affect subfragment-1. Urea also enhances the accessibility of thiol groups, promotes aggregation and decreases the alpha-helix content of S1, effects that are also counteracted by betaine. We conclude that urea-induced inactivation of the enzyme is caused by partial unfolding of the myosin catalytic domain.
Previous research has shown that L-carnitine L-tartrate (LCLT) supplementation beneficially affects markers of hypoxic stress following resistance exercise. However, the mechanism of this response is unclear. Therefore, the primary purpose of this study was to determine the effects of LCLT supplementation on muscle tissue oxygenation during and after multiple sets of squat exercise. Nine healthy, previously resistance-trained men (25.2 +/- 6.years, 91.2 +/- 10.2 kg, 180.2 +/- 6.3 cm) ingested 2 g.d of LCLT or an identical placebo for 23 days in a randomized, balanced, crossover, double-blind, placebo-controlled, repeated-measures study design. On day 21, forearm muscle oxygenation was measured during and after an upper arm occlusion protocol using near infrared spectroscopy (NIRS), which measures the balance of oxygen delivery in relation to oxygen consumption. On day 22, subjects performed 5 sets of 15 to 20 repetitions of squat exercise with corresponding measures of thigh muscle oxygenation, via NIRS, and serial blood draws. Compared to the placebo trial, muscle oxygenation was reduced in the LCLT trial during upper arm occlusion and following each set of resistance exercise. Despite reduced oxygenation, plasma malondealdehyde, a marker of membrane damage, was attenuated during the LCLT trial. There were no differences between trials in the vasoactive substance prostacyclin. In conclusion, because oxygen delivery was occluded during the forearm protocol, it is proposed that enhanced oxygen consumption mediated the reduced muscle oxygenation during the LCLT trial. Enhanced oxygen consumption would explain why hypoxic stress was attenuated with LCLT supplementation.
L-Carnitine L-tartrate supplementation favorably affects markers of recovery from exercise stress
- J S Volek
- Kraemer
- Wj
- Rubin
- Mr
- A L Gomez
- N A Ratamess
Volek, JS, Kraemer, WJ, Rubin, MR, Gomez, AL, Ratamess, NA, and
Gaynor, P. L-Carnitine L-tartrate supplementation favorably affects
markers of recovery from exercise stress. Am J Physiol Endocrinol
Metab 282: E474-E482, 2002.
Ferrari, M, Mottola, L, and Quaresima, V. Principles, techniques, and limitations of near infrared spectroscopy.
Hoffman, JR, Ratamess, NA, Kang, J, Rashti, SL, and Faigenbaum, AD. Effect of betaine supplementation on power performance and fatigue.
Goldstein, E, Jacobs, PL, Whitehurst, M, Penhollow, T, and Antonio, J. Caffeine enhances upper body strength in resistance-trained women.
Spiering, BA, Kraemer, WJ, Hatfield, DL, Vingren, JL, Fragala, MS, Ho, JY, Thomas, GA, Hakkinen, K, and Volek, JS. Effects of l-carnitine l-tartrate supplementation on muscle oxygenation responses to resistance exercise.
Armstrong, LE, Casa, DJ, Roti, MW, Lee, EC, Craig, SA, Sutherland, JW, Fiala, KA, and Maresh, CM. Influence of betaine consumption on strenuous running and sprinting in a hot environment.
Czapla, R, Swensen, T, and Craig, SA. Effect of betaine on cycling sprint power.
Vigneaud, V, Simmonds, S, Chandler, JP, and Cohn, M. A further investigation of the role of betaine in transmethylation reactions in vivo.
Jentzsch, AM, Bachmann, H, Furst, P, and Biesalski, HK. Improved analysis of malondialdehyde in human body fluids.