Skills and Expertise
Applied Science and Performance Institute
Research Items (85)
Studies utilizing beta-hydroxy-beta-methylbutyrate (HMB) supplementation in trained populations are limited. No long-term studies utilizing HMB free acid (HMB-FA) have been conducted. Therefore, we investigated the effects of 12 weeks of HMB-FA supplementation on skeletal muscle hypertrophy, body composition, strength, and power in trained individuals. We also determined the effects of HMB-FA on muscle damage and performance during an overreaching cycle. A three-phase double-blind, placebo- and diet-controlled randomized intervention study was conducted. Phase 1 was an 8-week-periodized resistance-training program; Phase 2 was a 2-week overreaching cycle; and Phase 3 was a 2-week taper. Muscle mass, strength, and power were examined at weeks 0, 4, 8, and 12 to assess the chronic effects of HMB-FA; and assessment of these, as well as cortisol, testosterone, and creatine kinase (CK) was performed at weeks 9 and 10 of the overreaching cycle. HMB-FA resulted in increased total strength (bench press, squat, and deadlift combined) over the 12-week training (77.1 ± 18.4 vs. 25.3 ± 22.0 kg, p < 0.001); a greater increase in vertical jump power (991 ± 168 vs. 630 ± 167 W, p < 0.001); and increased lean body mass gain (7.4 ± 4.2 vs. 2.1 ± 6.1 kg, p < 0.001) in HMB-FA- and placebo-supplemented groups, respectively. During the overreaching cycle, HMB-FA attenuated increases in CK (-6 ± 91 vs. 277 ± 229 IU/l, p < 0.001) and cortisol (-0.2 ± 2.9 vs. 4.5 ± 1.7 μg/dl, p < 0.003) in the HMB-FA- and placebo-supplemented groups, respectively. These results suggest that HMB-FA enhances hypertrophy, strength, and power following chronic resistance training, and prevents decrements in performance following the overreaching.
We previously demonstrated that static stretching was associated with a decrease in running economy and distance run during a 30-minute time trial in trained runners. Recently, the detrimental effects of static stretching on economy were found to be limited to the first few minutes of an endurance bout. However, economy remains to be studied for its direct effects on performance during shorter endurance events. PURPOSE: To investigate the effects of static stretching on one mile up hill run performance, electromyography, ground contact time, and flexibility. METHODS: Ten trained male distance runners aged 24±5 yr with an average VO2max of 64.9 ± 6.5 mL·kg·min were recruited. Subjects reported to the laboratory on 3 separate days interspersed by 72 hours. On day 1, anthropometrics and VO2max were determined on a motor driven treadmill. On days 2 and 3, subjects performed a 5-minute treadmill warm-up and either performed a series of 6 lower body stretches for 3, 30-second repetitions or sat still for 10 minutes. Time to complete a 1-mile run under stretching and non-stretching conditions took place in randomized order. For the performance run, subjects were instructed to run as fast as possible at a set incline of 5 % until a distance of 1 mile was completed. Flexibility from the sit and reach test, electromyography, ground contact time and performance, determined by time to complete the 1-mile run, were recorded following each condition. RESULTS: Time to complete the run was significantly less (6:51 ± 0:28 min) in the non-stretching condition as compared to the stretching condition (7:04 ± 0:32 min). A significant condition-by-time interaction for muscle activation existed, with no change in the non-stretching condition (pre 91.3 ± 11.6 mV to post 92.2 ± 12.9 mV), but increased in the stretching condition (pre 91.0 ± 11.6 mV to post 105.3 ± 12.9 mV). A significant condition-by-time interaction for GCT was also present, with no changes in the non-stretching condition (pre 211.4 ± 20.8 ms to post 212.5 ± 21.7 ms), but increased in the stretching trial (pre 210.7 ± 19.6 ms to post 237.21 ± 22.4 ms). A significant condition-by-time interaction for flexibility was found, which was increased in the stretching condition (pre 33.1 ± 2 to post 38.8 ± 2), but unchanged in the non-stretching condition (pre 33.5.± 2 to post 35.2 ± 2). CONCLUSIONS: Our findings indicate that static stretching decreases performance in short endurance bouts (∼8 %), while increasing GCT and muscle activation. PRACTICAL APPLICATIONS: Coaches and athletes may be at risk for decreased performance following a static stretching bout. Therefore, static stretching should be avoided prior to a short endurance bout.
- Feb 2013
Vascular blood flow restriction (vBFR) training stimulates muscle hypertrophy by increasing muscle activation and muscle swelling. Previous studies used expensive pneumatic cuffs, which may not be practical for regular use. PURPOSE:: To investigate the acute effects of low intensity practical BFR (LI-pBFR) on muscle activation, muscle swelling and damage. METHODS:: Twelve trained male participants completed a 30, 15, 15, 15 repetition scheme at 30% of their leg press 1-RM under control and LI-BFR conditions. Under the LI-BFR trial, knee wraps were applied to the thighs at a pressure which resulted in venous, not arterial, occlusion. In the control trial, wraps were applied with zero pressure. Ultrasound determined muscle thickness was recorded at baseline, 0 minutes post with wraps, 0, 5 and 10 minutes post without wraps. Muscle activation was recorded during warm ups and on the final set of 15 repetitions. Indices of muscle damage (soreness, power, and muscle swelling) were also recorded. RESULTS:: There was a condition by time effect for muscle thickness (p < 0.0001, ES = 0.5), in which muscle thickness increased in the LI-pBFR condition 0 minutes post with wraps and through 5 minutes post without wraps. No changes occurred in the control. There was a condition by time effect for muscle activation (p < .05, ES = 0.2). LI-pBFR had greater activation than the control. There were no condition by time effects on indices of muscle damage. DISCUSSION:: Our data indicates that practical BFR significantly increases muscle activation and muscle thickness without increasing indices of damage.
The purpose of the present study was to determine the effects of short-term supplementation with the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) on indices of muscle damage, protein breakdown, recovery and hormone status following a high-volume resistance training session in trained athletes. A total of twenty resistance-trained males were recruited to participate in a high-volume resistance training session centred on full squats, bench presses and dead lifts. Subjects were randomly assigned to receive either 3 g/d of HMB-FA or a placebo. Immediately before the exercise session and 48 h post-exercise, serum creatine kinase (CK), urinary 3-methylhistadine (3-MH), testosterone, cortisol and perceived recovery status (PRS) scale measurements were taken. The results showed that CK increased to a greater extent in the placebo (329 %) than in the HMB-FA group (104 %) (P = 0·004, d = 1·6). There was also a significant change for PRS, which decreased to a greater extent in the placebo (9·1 (sem 0·4) to 4·6 (sem 0·5)) than in the HMB-FA group (9·1 (sem 0·3) to 6·3 (sem 0·3)) (P = 0·005, d = - 0·48). Muscle protein breakdown, measured by 3-MH analysis, numerically decreased with HMB-FA supplementation and approached significance (P = 0·08, d = 0·12). There were no acute changes in plasma total or free testosterone, cortisol or C-reactive protein. In conclusion, these results suggest that an HMB-FA supplement given to trained athletes before exercise can blunt increases in muscle damage and prevent declines in perceived readiness to train following a high-volume, muscle-damaging resistance-training session.
Background: Muscle mass is an important determinant of metabolic health and physical function. It has previously been demonstrated that the postprandial rise in circulating essential amino acids (EAA) acts as the main stimulus for muscle protein synthesis (MPS). This study investigated postprandial plasma amino acid (AA) responses of 2 different forms of whey protein isolate (WPI) with iso-caloric and iso-nitrogenous profiles to investigate plasma concentrations of EAA. Methods: In all, 12 healthy men (n = 12) between 19 and 32 years of age were recruited for a randomized, cross-over design, which involved consumption of protein supplements on 2 testing days separated by a 6-day washout period between conditions. On each testing day, subjects consumed either 29.6 g of WPI or WPI + io (whey protein isolate plus Ingredient Optimized Protein ® ) mixed with 236 mL of water. Plasma EAA and branch chain amino acid (BCAA) concentrations were assessed from whole body donated by subjects at pre-consumption and 30, 60, 90, 120, and 180 minutes post consumption. Results: Plasma levels of total EAA concentration was significantly greater in WPI + io at 30, 60, 90, and 120 minutes post consumption ( P
Introduction Krill oil supplementation has been shown to improve postexercise immune function; however, its effect on muscle hypertrophy is currently unknown. Therefore, the aim of present study was to investigate the ability of krill oil to stimulate mTOR signaling and its ability to augment resistance training-induced changes in body composition and performance. Methods C2C12 myoblasts cells were stimulated with krill oil or soy-derived phosphatidylcholine (S-PC), and then, the ratio of P-p70-389 to total p70 was used as readout for mTOR signaling. In double-blind, placebo-controlled study, resistance trained subjects consumed either 3 g krill oil daily or placebo, and each took part in an 8-week periodized resistance training program. Body composition, maximal strength, peak power, and rate of perceived recovery were assessed collectively at the end of weeks 0 and 8. In addition, safety parameters (comprehensive metabolic panel (CMP), complete blood count (CBC), and urine analysis (UA)) and cognitive performance were measured pre- and posttesting. Results Krill oil significantly stimulated mTOR signaling in comparison to S-PC and control. No differences for markers on the CMP, CBC, or UA were observed. Krill oil significantly increased lean body mass from baseline (p=0.021, 1.4 kg, +2.1%); however, there were no statistically significant differences between groups for any measures taken. Conclusion Krill oil activates mTOR signaling. Krill oil supplementation in athletes is safe, and its effect on resistance exercise deserves further research.
Dietary fibre refers to nutrients in the diet that gastrointestinal enzymes do not digest. If properly labelled, dietary fibres should not significantly elevate blood glucose or insulin and should ferment in the large intestine. Because of the recent rise in low-carbohydrate products on the market, consumers use these various fibres without adequate knowledge concerning whether or not these ingredients affect any blood parameters and constitute a dietary fibre. The aim of this study was to examine the impact of isomaltooligosaccharides (IMO) as compared to soluble corn fibre (SCF) consumption on blood glucose, insulin and breath hydrogen responses in healthy young men and women. After an overnight fast, nine individuals consumed 25 g of either placebo (PLA), IMO or SCF. Breath hydrogen was significantly higher in the SCF condition than in the IMO and PLA at 90, 120, 150 and 180 min (p < 0.0001). Blood glucose and insulin were higher in the IMO condition (p < 0.0001) at 30 min compared to the SCF or PLA conditions, which were not significantly different from each other. These data suggest that IMO does not constitute a dietary fibre and instead should be explored as a slow-digesting carbohydrate.
Adopting low carbohydrate, ketogenic diets remains a controversial issue for individuals who resistance train given that this form of dieting has been speculated to reduce skeletal muscle glycogen levels and stifle muscle anabolism. We sought to characterize the effects of a 12-week ketogenic diet (KD) on body composition, metabolic, and performance parameters in participants who trained recreationally at a local CrossFit facility. Twelve participants (nine males and three females, 31 ± 2 years of age, 80.3 ± 5.1 kg body mass, 22.9 ± 2.3% body fat, 1.37 back squat: body mass ratio) were divided into a control group (CTL; n = 5) and a KD group (n = 7). KD participants were given dietary guidelines to follow over 12 weeks while CTL participants were instructed to continue their normal diet throughout the study, and all participants continued their CrossFit training routine for 12 weeks. Pre, 2.5-week, and 12-week anaerobic performance tests were conducted, and pre- and 12-week tests were performed for body composition using dual X-ray absorptiometry (DXA) and ultrasound, resting energy expenditure (REE), blood-serum health markers, and aerobic capacity. Additionally, blood beta hydroxybutyrate (BHB) levels were measured weekly. Blood BHB levels were 2.8- to 9.5-fold higher in KD versus CTL throughout confirming a state of nutritional ketosis. DXA fat mass decreased by 12.4% in KD (p = 0.053). DXA total lean body mass changes were not different between groups, although DXA dual-leg lean mass decreased in the KD group by 1.4% (p = 0.068), and vastus lateralis thickness values decreased in the KD group by ~8% (p = 0.065). Changes in fasting glucose, HDL cholesterol, and triglycerides were similar between groups, although LDL cholesterol increased ~35% in KD (p = 0.048). Between-group changes in REE, one-repetition maximum (1-RM) back squat, 400 m run times, and VO2peak were similar between groups. While our n-sizes were limited, these preliminary data suggest that adopting a ketogenic diet causes marked reductions in whole-body adiposity while not impacting performance measures in recreationally-trained CrossFit trainees. Whether decrements in dual-leg muscle mass and vastus lateralis thickness in KD participants were due to fluid shifts remain unresolved, and increased LDL-C in these individuals warrants further investigation.
We determined the short- and long-term effects of a ketogenic diet (KD) or ketone salt (KS) supplementation on multi-organ oxidative stress and mitochondrial markers. For short-term feedings, 4 month-old male rats were provided isocaloric amounts of KD (n = 10), standard chow (SC) (n = 10) or SC + KS (~1.2 g/day, n = 10). For long-term feedings, 4 month-old male rats were provided KD (n = 8), SC (n = 7) or SC + KS (n = 7) for 8 months and rotarod tested every 2 months. Blood, brain (whole cortex), liver and gastrocnemius muscle were harvested from all rats for biochemical analyses. Additionally, mitochondria from the brain, muscle and liver tissue of long-term-fed rats were analyzed for mitochondrial quantity (maximal citrate synthase activity), quality (state 3 and 4 respiration) and reactive oxygen species (ROS) assays. Liver antioxidant capacity trended higher in short-term KD- and SC + KS-fed versus SC-fed rats, and short-term KD-fed rats exhibited significantly greater serum ketones compared to SC + KS-fed rats indicating that the diet (not KS supplementation) induced ketonemia. In long term-fed rats: (a) serum ketones were significantly greater in KD- versus SC- and SC + KS-fed rats; (b) liver antioxidant capacity and glutathione peroxidase protein was significantly greater in KD- versus SC-fed rats, respectively, while liver protein carbonyls were lowest in KD-fed rats; and (c) gastrocnemius mitochondrial ROS production was significantly greater in KD-fed rats versus other groups, and this paralleled lower mitochondrial glutathione levels. Additionally, the gastrocnemius pyruvate-malate mitochondrial respiratory control ratio was significantly impaired in long-term KD-fed rats, and gastrocnemius mitochondrial quantity was lowest in these animals. Rotarod performance was greatest in KD-fed rats versus all other groups at 2, 4 and 8 months, although there was a significant age-related decline in performance existed in KD-fed rats which was not evident in the other two groups. In conclusion, short- and long-term KD improves select markers of liver oxidative stress compared to SC feeding, although long-term KD feeding may negatively affect skeletal muscle mitochondrial physiology.
Alterations in transcriptional and translational mechanisms occur during skeletal muscle aging and such changes may contribute to age-related atrophy. Herein, we examined markers related to global transcriptional output (i.e., myonuclear number, total mRNA and RNA pol II levels), translational efficiency [i.e., eukaryotic initiation and elongation factor levels and muscle protein synthesis (MPS) levels] and translational capacity (ribosome density) in the slow-twitch soleus and fast-twitch plantaris muscles of male Fischer 344 rats aged 3, 6, 12, 18, and 24 months (n = 9–10 per group). We also examined alterations in markers of proteolysis and oxidative stress in these muscles (i.e., 20S proteasome activity, poly-ubiquinated protein levels and 4-HNE levels). Notable plantaris muscle observations included: (a) fiber cross sectional area (CSA) was 59% (p < 0.05) and 48% (p < 0.05) greater in 12 month vs. 3 month and 24 month rats, respectively, suggesting a peak lifetime value near 12 months and age-related atrophy by 24 months, (b) MPS levels were greatest in 18 month rats (p < 0.05) despite the onset of atrophy, (c) while regulators of ribosome biogenesis [c-Myc and upstream binding factor (UBF) protein levels] generally increased with age, ribosome density linearly decreased from 3 months of age and RNA polymerase (Pol) I protein levels were lowest in 24 month rats, and d) 20S proteasome activity was robustly up-regulated in 6 and 24 month rats (p < 0.05). Notable soleus muscle observations included: (a) fiber CSA was greatest in 6 month rats and was maintained in older age groups, and (b) 20S proteasome activity was modestly but significantly greater in 24 month vs. 3/12/18 month rats (p < 0.05), and (c) total mRNA levels (suggestive of transcriptional output) trended downward in older rats despite non-significant between-group differences in myonuclear number and/or RNA Pol II protein levels. Collectively, these findings suggest that plantaris, not soleus, atrophy occurs following 12 months of age in male Fisher rats and this may be due to translational deficits (i.e., changes in MPS and ribosome density) and/or increases in proteolysis rather than increased oxidative stress and/or alterations in global transcriptional mechanisms.
The purpose of this study was to determine the effects of post-workout consumption of beef protein isolate (Beef), hydrolyzed chicken protein (Chx) or whey protein concentrate (WPC), compared to a control on lean mass and strength during 8 weeks of resistance training. Forty-one males and females were randomized into four groups: WPC (m=5, f=5; Age (yrs)=19 ± 2, Height (cm)=171 ± 10, Mass (kg)= 74.60 ± 14.19), Beef (m=5, f=5; Age (yrs)=22 ± 4, Height (cm)=170 ± 7, Mass (kg)=70.13 ± 8.16), ChxC(m=5, f=6; Age (yrs)=21 ± 2, Height (cm)=169 ± 9, Mass (kg)=74.52 ± 13.83) and Maltodextrin (control) (m=4, f=6; Age (yrs)= 21 ± 2, Height (cm)=170 ± 9, Mass (kg)= 73.18 ± 10.96). Subjects partook in an 8-week periodized resistance-training program. Forty-six grams of protein or a control were consumed immediately following training or at similar times on off-days. Dual energy x-ray absorptiometry (DXA) was used to determine changes in body composition. Maximum strength were assessed by one repetition maximum (1RM) for bench press (upper body) and deadlift (lower body). Power output was measured using cycle ergometer. WPC (52.48 ± 11.15 to 54.96 ± 11.85), Beef (51.68 ± 7.61kg to 54.65 ± 8.67kg) and Chx (52.97 ± 12.12kg to 54.89 ± 13.43kg) each led to a significant increase in lean body mass compared with baseline (p<0.0001) while the control condition did not (53.14 ± 11.35kg to 54.19 ± 10.74kg). Fat loss was also significantly decreased at 8 weeks compared to baseline for all protein sources (WPC: 18.70 ± 7.38kg to 17.16 ± 7.18kg; Beef: 16.43 ± 5.71kg to 14.65 ± 5.41kg; Chx: 17.58 ± 5.57kg to 15.87 ± 6.07kg), but not the control condition (16.29 ± 7.14kg to 14.95 ± 7.72) (p<0.0001). One repetition maximum for both deadlift and bench-press were significantly increased for all treatment groups when compared to baseline. No differences in strength were noted between conditions. Overall, the results of this study demonstrate that consuming quality sources of protein from meat or WPC lead to significant benefits in body composition compared to control.
- Apr 2017
Methods: Twenty-five college aged men were divided into a KD or traditional WD from weeks 1-10, with a reintroduction of carbohydrates from weeks 10-11, while participating in a resistance-training program. Body composition, strength, power, and blood lipid profiles were determined at week 0, 10 and 11. A comprehensive metabolic panel and testosterone levels were also measured at weeks 0 and 11. Results: Lean body mass (LBM) increased in both KD and WD groups (2.4% and 4.4%, p<0.01) at week 10. However, only the KD group showed an increase in LBM between weeks 10-11 (4.8%, p<0.0001). Finally, fat mass decreased in both the KD group (-2.2 kg ± 1.2 kg) and WD groups (- 1.5 ± 1.6 kg). Strength and power increased to the same extent in the WD and KD conditions from weeks 1-11. No changes in any serum lipid measures occurred from weeks 1-10, however a rapid reintroduction of carbohydrate from weeks 10-11 raised plasma TG levels in the KD group. Total testosterone increased significantly from Weeks 0-11 in the KD diet (118 ng/dl) as compared to the WD (-36 ng/dl) from pre to post while insulin did not change. Conclusions: The KD can be used in combination with resistance training to cause favorable changes in body composition, performance and hormonal profiles in resistance-trained males.
- Mar 2017
We examined if 6 weeks of progressive resistance-loaded voluntary wheel running in rats induced plantaris, soleus, and/or gastrocnemius hypertrophy and/or affected markers of translational efficiency, ribosome biogenesis, and markers of proteolysis. For 6 weeks, 8 male Sprague-Dawley rats (~9-10 weeks of age, ~300-325 g) rats were assigned to the progressive resistance-loaded voluntary wheel running model (EX), and ten rats were not trained (SED). For EX rats, the wheel-loading paradigm was as follows - days 1-7: free-wheel resistance, days 8-15: wheel resistance set to 20%-25% body mass, days 16-24: 40% body mass, days 25-32: 60% body mass, days 33-42: 40% body mass. Following the intervention, muscles were analysed for markers of translational efficiency, ribosome biogenesis, and muscle proteolysis. Raw gastrocnemius mass (+13%, p < .01), relative (body mass-corrected) gastrocnemius mass (+16%, p < .001), raw plantaris mass (+13%, p < .05), and relative plantaris mass (+15%, p < .01) were greater in EX vs. SED rats. In spite of gastrocnemius hypertrophy, EX animals presented a 54% decrease in basal muscle protein synthesis levels (p < .01), a 125% increase in pan 4EBP1 levels (p < .001) and a 31% decrease in pan eIF4E levels (p < .05). However, in relation to SED animals, EX animals presented a 70% increase in gastrocnemius c-Myc protein levels (p < .05). Most markers of translational efficiency and ribosome biogenesis were not altered in the plantaris or soleus muscles of EX vs. SED animals. Gastrocnemius F-box protein 32 and poly-ubiquinated protein levels were approximately 150% and 200% greater in SED vs. EX rats (p < .001). These data suggest that the employed resistance training model increases hind limb muscle hypertrophy, and this may be mainly facilitated through reductions in skeletal muscle proteolysis, rather than alterations in ribosome biogenesis or translational efficiency.
PurposeThe optimal health benefits of curcumin are limited by its low solubility in water and corresponding poor intestinal absorption. Cyclodextrins (CD) can form inclusion complexes on a molecular basis with lipophilic compounds, thereby improving aqueous solubility, dispersibility, and absorption. In this study, we investigated the bioavailability of a new γ-cyclodextrin curcumin formulation (CW8). This formulation was compared to a standardized unformulated curcumin extract (StdC) and two commercially available formulations with purported increased bioavailability: a curcumin phytosome formulation (CSL) and a formulation of curcumin with essential oils of turmeric extracted from the rhizome (CEO). Methods Twelve healthy human volunteers participated in a double-blinded, cross-over study. The plasma concentrations of the individual curcuminoids that are present in turmeric (namely curcumin, demethoxycurcumin, and bisdemethoxycurcumin) were determined at baseline and at various intervals after oral administration over a 12-h period. ResultsCW8 showed the highest plasma concentrations of curcumin, demethoxycurcumin, and total curcuminoids, whereas CSL administration resulted in the highest levels of bisdemethoxycurcumin. CW8 (39-fold) showed significantly increased relative bioavailability of total curcuminoids (AUC0−12) in comparison with the unformulated StdC. Conclusion The data presented suggest that γ-cyclodextrin curcumin formulation (CW8) significantly improves the absorption of curcuminoids in healthy humans.
- Jan 2017
Objective: Oral adenosine-5'-triphosphate (ATP) administration has failed to increase plasma ATP levels; however, chronic supplementation with ATP has shown to increase power, strength, lean body mass, and blood flow in trained athletes. The purpose of this study was to investigate the effects of ATP supplementation on postexercise ATP levels and on muscle activation and excitability and power following a repeated sprint bout. Methods: In a double-blind, placebo-controlled, randomized design, 42 healthy male individuals were given either 400 mg of ATP as disodium salt or placebo for 2 weeks prior to an exercise bout. During the exercise bout, muscle activation and excitability (ME, ratio of power output to muscle activation) and Wingate test peak power were measured during all sprints. ATP and metabolites were measured at baseline, after supplementation, and immediately following exercise. Results: Oral ATP supplementation prevented a drop in ATP, adenosine-5'-diphosphate (ADP), and adenosine-5'-monophosphate (AMP) levels postexercise (p < 0.05). No group by time interaction was observed for muscle activation. Following the supplementation period, muscle excitability significantly decreased in later bouts 8, 9, and 10 in the placebo group (-30.5, -28.3, and -27.9%, respectively; p < 0.02), whereas ATP supplementation prevented the decline in later bouts. ATP significantly increased Wingate peak power in later bouts compared to baseline (bout 8: +18.3%, bout 10: +16.3%). Conclusions: Oral ATP administration prevents exercise-induced declines in ATP and its metabolite and enhances peak power and muscular excitability, which may be beneficial for sports requiring repeated high-intensity sprinting bouts.
Purpose: Ketogenic diets (KD) can facilitate weight loss, but their effects on skeletal muscle remain equivocal. In this experiment we investigated the effects of two diets on skeletal muscle mitochondrial coupling, mitochondrial complex activity, markers of oxidative stress, and gene expression in sedentary and resistance exercised rats. Methods: Male Sprague-Dawley rats (9–10 weeks of age, 300–325 g) were fed isocaloric amounts of either a KD (17 g/day, 5.2 kcal/g, 20.2% protein, 10.3% CHO, 69.5% fat, n = 16) or a Western diet (WD) (20 g/day, 4.5 kcal/g, 15.2% protein, 42.7% CHO, 42.0% fat, n = 16) for 6 weeks. During these 6 weeks animals were either sedentary (SED, n = 8 per diet group) or voluntarily exercised using resistance-loaded running wheels (EXE, n = 8 per diet group). Gastrocnemius was excised and used for mitochondrial isolation and biochemical analyses. Results: In the presence of a complex II substrate, the respiratory control ratio (RCR) of isolated gastrocnemius mitochondria was higher (p < 0.05) in animals fed the KD compared to animals fed the WD. Complex I and IV enzyme activity was higher (p < 0.05) in EXE animals regardless of diet. SOD2 protein levels and GLUT4 and PGC1α mRNA expression were higher (p < 0.05) in EXE animals regardless of diet. Conclusion: Our data indicate that skeletal muscle mitochondrial coupling of complex II substrates is more efficient in chronically resistance trained rodents fed a KD. These findings may provide merit for further investigation, perhaps on humans.
Effects of MusclePharm Assault BlackTM on lower extremity spinal excitability and postactivation potentiation: A pilot study Brian Wallace*, Haley Bergstrom, Kelly Wallace Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA Email: email@example.com; firstname.lastname@example.org Background: Caffeine has been shown to increase muscular strength, power, and endurance, and is the main active ingredient in the dietary supplement Assault BlackTM (MusclePharm, Denver, CO, USA). Muscle performance can be enhanced via post-activation potentiation (PAP). PAP is achieved through the modulation of neuromuscular function via increased spinal excitability of motor units as measured by the Hoffmann Reflex (Hmax/Mmax ratio), or from increased calcium sensitivity as a result of myosin light chain phosphorylation (Mmax force), following a conditioning activity such as heavy resistance exercise or a maximum voluntary isometric contraction (MVIC). The purpose of this study was to investigate the effect of Assault BlackTM on PAP of the soleus. Methods: Five men and three women (26.5 ± 6.4 years, 173.5 ± 13.9 cm, 79.9 ± 20.7 kg) with at least one year of continuous strength training experience volunteered. Men and women were required to back squat at least 1.5 and 1.0 times bodyweight, respectively. A randomized crossover design was utilized, where subjects received either the supplement or a placebo on alternating visits. Men received 1.5 servings and women received 1 serving of the supplement. Each serving contained 300mg caffeine. Twenty minutes after consumption of the beverage subjects were positioned on a Biodex System 4 isokinetic dynamometer (Biodex Medical Systems, Shirley, NY) with standardized positioning. Their foot was attached to the foot plate where plantarflexion force was recorded. A Hmax-Mmax stimulus response curve was obtained by delivering 1ms duration twitches of increasing intensity to the soleus via square-wave impulses sent to the tibial nerve (Model DS7AH, Digitimer, Ltd., UK). Electromyography (EMG) recorded action potentials of the soleus (Bagnoli-8, Delsys, Inc., Boston, MA). Electrode placements were marked to ensure consistent placement for the subsequent visit. Ten minutes after the stimulus response curve was obtained, subjects performed a 10 second MVIC plantarflexion conditioning activity. Ten seconds thereafter, they received a stimulation at the intensity which elicited a maximum amplitude M-wave (Mmax), +20%, followed ten seconds thereafter by a twitch at the intensity that elicited a maximum H-wave (Hmax). The H/M ratio, force in response to the Mmax and Hmax twitches, and MVIC peak force were analyzed in SPSS (version 22) using paired t-tests. The level of significance was p<0.05. Results: The supplement significantly increased PAP as measured by both increased spinal excitability (mean difference: 10.29 ± 10.91%, p=0.03) and increased muscular calcium sensitivity (2.30 ± 2.74 Nm, p=0.04). The net PAP response to the conditioning activity, which is a combination of the neural and muscular contributions measured by force at Hmax, was not different (-0.73 ± 3.78 Nm, p=0.60). Subjects’ peak MVIC force was equal between conditions (p=0.23). Conclusions: Ingesting Assault BlackTM lead to significantly greater spinal excitability and phosphorylation induced PAP, but not net PAP. After a conditioning activity spinal excitability has been shown to be moderated for several minutes before increasing. A longer period of time may be necessary for net potentiation to become apparent. Acknowledgement: This study was funded by MusclePharm through the ISSN Unrestricted Educational Grant.
Objective: Probiotics have been reported to support healthy digestive and immune function, aid in protein absorption, and decrease inflammation. Further, a trend to increase vertical jump power has been observed following co-administration of protein and probiotics in resistance-trained subjects. However, to date the potential beneficial effect of probiotics on recovery from high intensity resistance exercise have yet to be explored. Therefore, this study examined the effect of co-administration of protein and probiotics on muscle damage, recovery and performance following a damaging exercise bout. Design: Twenty nine (n=29) recreationally-trained males (mean±SD; 21.5±2.8 years; 89.7±28.2 kg; 177.4±8.0 cm) were assigned to consume either 20g of casein (PRO) or 20g of casein plus probiotic (1 billion CFU Bacillus coagulans GBI-30, 6086, PROBC) in a crossover, diet-controlled design. After two weeks of supplementation, perceptional measures, athletic performance, and muscle damage were analyzed following a damaging exercise bout. Results: The damaging exercise bout significantly increased muscle soreness, and reduced perceived recovery; however, PROBC significantly increased recovery at 24 and 72 hours, and decreased soreness at 72 hours post exercise in comparison to PRO. Perceptual measures were confirmed by increases in CK (PRO: +266.8%, p=0.0002; PROBC: +137.7%, p=0.01), with PROBC showing a trend towards reduced muscle damage (p=0.08). The muscle-damaging exercise resulted in significantly increased muscle swelling and Blood Urea Nitrogen levels in both conditions with no difference between groups. The strenuous exercise significantly reduced athletic performance in PRO (Wingate Peak Power; PRO: (-39.8 watts, - 5.3%, p=0.03)), whereas PROBC maintained performance by (+10.1 watts, +1.7%). Conclusions: The results provide evidence that probiotic supplementation in combination with protein tended to reduce indices of muscle damage, improves recovery, and maintains physical performance subsequent to damaging exercise.
Adenosine-5'-triphosphate (ATP) supplementation helps maintain performance under high fatiguing contractions and with greater fatigue recovery demands also increase. Current evidence suggests that the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) acts by speeding regenerative capacity of skeletal muscle following high intensity or prolonged exercise. Therefore, we investigated the effects of 12 weeks of HMB-FA (3g) and ATP (400mg) administration on lean mass (LBM), strength, and power in trained individuals. A 3-phase double-blind, placebo- and diet-controlled study was conducted. Phases consisted of an 8-week periodized resistance-training program (Phase 1), followed by a 2-week overreaching cycle (Phase 2), and a 2-week taper (Phase 3). Lean body mass was increased by a combination of HMB-FA/ATP by 12.7% (p < 0.001). In a similar fashion, strength gains following training were increased in HMB-FA/ATP-supplemented subjects by 23.5% (p < 0.001). Vertical jump and Wingate power were increased in the HMB-FA/ATP-supplemented group compared to the placebo-supplemented group and the 12-week increases were 21.5% and 23.7% respectively. During the overreaching cycle, strength and power declined in the placebo group (4.3 to 5.7%) while supplementation with HMB-FA/ATP resulted in continued strength gains (1.3%). In conclusion HMB-FA and ATP in combination with resistance exercise training enhanced LBM, power, and strength. In addition, HMB-FA plus ATP blunted the typical response to overreaching, resulting in a further increase in strength during that period. It appears that the combination of HMB-FA/ATP could benefit those who continuously train at high levels such as elite athletes or military personnel.
- Jun 2016
We investigated the effects different diets on adipose tissue, liver and serum morphology and biomarkers in rats that voluntarily exercised. Male Sprague-Dawley rats (~9-10 weeks of age) exercised with resistance-loaded voluntary running wheels (EX; wheels loaded with 20-60% body mass) or remained sedentary (SED) over 6 weeks. EX and SED rats were provided isocaloric amounts of either a ketogenic diet (KD; 20.2%-10.3%-69.5% protein-carbohydrate-fat), a Western diet (WD; 15.2%-42.7-42.0%), or standard chow (SC; 24.0%-58.0%-18.0%); n=8-10 in each diet for SED and EX rats. Following the intervention, body mass and feed efficiency was lowest in KD rats independent of exercise (p<0.05). Absolute and relative (body mass-adjusted) omental adipose tissue (OMAT) masses were greatest in WD rats (p<0.05) and OMAT adipocyte diameters were lowest in KD-fed rats (p<0.05). None of the assayed OMAT or subcutaneous (SQ) protein markers were affected by the diets [total acetyl coA carboxylase (ACC), CD36 and CEBPα or phosphorylated NF-κB/p65, AMPKα and hormone-sensitive lipase (HSL)], although EX unexpectedly altered some OMAT markers (i.e., higher ACC and phosphorylated NF-κB/p65, and lower phosphorylated AMPKα and phosphorylated HSL). Liver triglycerides were greatest in WD rats (p<0.05) and liver phosphorylated NF-κB/p65 was lowest in KD rats (p<0.05). Serum insulin, glucose, triglycerides and total cholesterol were greater in WD and/or SC rats compared to KD rats (p<0.05), and serum β-hydroxybutyrate was greater in KD versus SC rats (p<0.05). In conclusion, KD rats presented a healthier metabolic profile, albeit the employed exercise protocol minimally impacts any potentiating effects that KD has on fat loss.
Objective: The purpose of this study was to investigate the effects of Fortetropin on skeletal muscle growth and strength in resistance-trained individuals and to investigate the anabolic and catabolic signaling effects using human and rodent models. Methods: In the rodent model, male Wistar rats (250 g) were gavage fed with either 1.2 ml of tap water control (CTL) or 0.26 g Fortetropin for 8 days. Then rats participated in a unilateral plantarflexion exercise bout. Nonexercised and exercised limbs were harvested at 180 minutes following and analyzed for gene and protein expression relative to mammalian target of rapamycin (mTOR) and ubiquitin signaling. For the human model, 45 (of whom 37 completed the study), resistance-trained college-aged males were divided equally into 3 groups receiving a placebo macronutrient matched control, 6.6 or 19.8 g of Fortetropin supplementation during 12 weeks of resistance training. Lean mass, muscle thickness, and lower and upper body strength were measured before and after 12 weeks of training. Results: The human study results indicated a Group × Time effect (p ≤ 0.05) for lean mass in which the 6.6 g (+1.7 kg) and 19.8 g (+1.68 kg) but not placebo (+0.6 kg) groups increased lean mass. Similarly, there was a Group × Time effect for muscle thickness (p ≤ 0.05), which increased in the experimental groups only. All groups increased equally in bench press and leg press strength. In the rodent model, a main effect for exercise (p ≤ 0.05) in which the control plus exercise but not Fortetropin plus exercise increased both ubiquitin monomer protein expression and polyubiquitination. mTOR signaling was elevated to a greater extent in the Fortetropin exercising conditions as indicated by greater phosphorylation status of 4EBP1, rp6, and p70S6K for both exercising conditions. Conclusions: Fortetropin supplementation increases lean body mass (LBM) and decreases markers of protein breakdown while simultaneously increasing mTOR signaling.
Background The primary purpose of this investigation was to examine the effects of arachidonic acid (ARA) supplementation on functional performance and body composition in trained males. In addition, we performed a secondary study looking at molecular responses of ARA supplementation following an acute exercise bout in rodents. Methods Thirty strength-trained males (age: 20.4 ± 2.1 yrs) were randomly divided into two groups: ARA or placebo (i.e. CTL). Then, both groups underwent an 8-week, 3-day per week, non-periodized training protocol. Quadriceps muscle thickness, whole-body composition scan (DEXA), muscle strength, and power were assessed at baseline and post-test. In the rodent model, male Wistar rats (~250 g, ~8 weeks old) were pre-fed with either ARA or water (CTL) for 8 days and were fed the final dose of ARA prior to being acutely strength trained via electrical stimulation on unilateral plantar flexions. A mixed muscle sample was removed from the exercised and non-exercised leg 3 hours post-exercise. Results Lean body mass (2.9%, p<0.0005), upper-body strength (8.7%, p<0.0001), and peak power (12.7%, p<0.0001) increased only in the ARA group. For the animal trial, GSK-β (Ser9) phosphorylation (p<0.001) independent of exercise and AMPK phosphorylation after exercise (p-AMPK less in ARA, p = 0.041) were different in ARA-fed versus CTL rats. Conclusions Our findings suggest that ARA supplementation can positively augment strength-training induced adaptations in resistance-trained males. However, chronic studies at the molecular level are required to further elucidate how ARA combined with strength training affect muscle adaptation.
Periods of intense training can elicit an acute decline in performance and body composition associated with weakened hormone profiles. This study investigated the effects of a multi-ingredient performance supplement (MIPS) on body composition and hormone levels in college athletes following a six-week training protocol. Twenty male college athletes were equally assigned to MIPS and placebo (PLA) groups for supplementation (three pills, twice daily) in conjunction with resistance training and specialized sports training (e.g., nine total sessions/week) for six weeks. Dual Energy X-ray Absorptiometry determined body composition at weeks 0 and 6. Serum samples collected at weeks 0 and 6 determined free testosterone (FT), total testosterone (TT), IGF-1 and total estrogen (TE) levels. PLA experienced a significant decline in lean body mass (LBM) (−1.5 kg; p < 0.05) whereas the MIPS sustained LBM. The MIPS increased TT 21.9% (541.5 ± 48.7 to 639.1 ± 31.7) and increased FT 15.2% (13.28 ± 1.1 to 15.45 ± 1.3 ng/dL) (p < 0.05). Conversely, PLA decreased TT 7.9% (554.5 ± 43.3 to 497.2 ± 39.1 ng/dL), decreased FT 17.4% (13.41 ± 1.8 to 11.23 ± 2.55 ng/dL), and decreased FT:E 12.06% (p < 0.05). These findings suggest the MIPS can prevent decrements in LBM and anabolic hormone profiles during intense training periods.
Many sports involve repeated bouts of high-intensity exercise. High-intensity exercise is compromised, however, by the early onset of exercise-induced fatigue. Metabolic by-products, ion dysbalance and amount of phosphocreatine are considered the main peripheral causes of fatigue during high-intensity exercise. Intake of nutritional ergogenic aids is commonplace to enhance performance of high-intensity exercise by offsetting the potential mechanisms of fatigue. Creatine, probably one of the best known nutritional aids to enhance performance of high-intensity exercise, has convincingly substantiated its ergogenic potential. Although multi-ingredient supplements are now common, the justification for effectiveness is mostly based on observations with single intake of those ingredients. In this narrative review, the main focus is on the evidence of the effect of co-ingestion of ergogenic aids on performance of high intensity exercise for which the single intake has shown beneficial effects on high-intensity performance.
We examined whether acute and/or chronic skeletal muscle anabolism is impaired with a low carbohydrate diet formulated to elicit ketosis (LCKD) versus a mixed-macronutrient Western diet (WD). Male Sprague-Dawley rats (9-10 weeks of age, 300-325 g) were provided isoenergetic amounts of a LCKD or a WD for 6 weeks. In AIM 1, basal serum and gastrocnemius assessments were performed. In AIM 2, rats were resistance-exercised for one bout and were euthanized 90-270 min following exercise for gastrocnemius analyses. In AIM 3, rats voluntarily-exercised daily using resistance-loaded running wheels, and hind limb muscles were analyzed for hypertrophy markers at the end of the 6 week protocol. In AIM 1, basal levels of gastrocnemius phosphorylated (p)-rps6, p-4EBP1 and p-AMPKα were similar between diets, although serum insulin (P<0.01), serum glucose (P<0.001), and several essential amino acid levels (P<0.05) were lower in LCKD-fed rats. In AIM 2, LCKD- and WD-fed rats exhibited increased post-exercise muscle protein synthesis (MPS) levels (P<0.0125), but no diet effect was observed (P=0.59). In AIM 3, chronically exercise-trained LCKD- and WD-fed rats presented similar increases in relative hind limb muscle masses compared to their sedentary counterparts (12-24%, p<0.05), but there was no between-diet effects. Importantly, the LCKD induced 'mild' nutritional ketosis, as the LCKD-fed rats in AIM 2 exhibited ~1.5-fold greater serum beta-hydroxybutyrate levels relative to WD-fed rats (diet effect P=0.003). This study demonstrates that the tested LCKD in rodents, while only eliciting mild nutritional ketosis, does not impair the acute or chronic skeletal muscle hypertrophic responses to resistance exercise.
Phosphatidic acid (PA) is a diacyl-glycerophospholipid that acts as a signaling molecule in numerous cellular processes. Recently, PA has been proposed to stimulate skeletal muscle protein accretion, but mechanistic studies are lacking. Furthermore, it is unknown whether co-ingesting PA with other leucine-containing ingredients can enhance intramuscular anabolic signaling mechanisms. Thus, the purpose of this study was to examine if oral PA feeding acutely increases anabolic signaling markers and muscle protein synthesis (MPS) in gastrocnemius with and without whey protein concentrate (WPC). Overnight fasted male Wistar rats (~250 g) were randomly assigned to four groups: control (CON, n = 6-13), PA (29 mg; n = 8), WPC (197 mg; n = 8), or PA + WPC (n = 8). Three hours post-feeding, gastrocnemius muscle was removed for markers of Akt-mTOR signaling, gene expression patterns related to skeletal muscle mass regulation and metabolism, and MPS analysis via the SUnSET method. Compared to CON rats, PA, WPC and PA + WPC resulted in a significant elevation in the phosphorylation of mTOR (Ser2481) and rps6 (Ser235/236) (p < 0.05) in the gastrocnemius though there were no differences between the supplemented groups. MPS levels in the gastrocnemius were significantly (p < 0.05) elevated in WPC versus CON rats, and tended to be elevated in PA versus CON rats (p = 0.08), though MPS was less in PA + WPC versus WPC rats (p < 0.05) in spite of robust increases in mTOR pathway activity markers in the former group. C2C12 myoblast data agreed with the in vivo data herein showing that PA increased MPS levels 51% (p < 0.001) phosphorylated p70s6k (Thr389) levels 67% (p < 0.001). Our results are the first in vivo evidence to demonstrate that PA tends to increases MPS 3 h post-feeding, though PA may delay WPC-mediated MPS kinetics within a 3 h post-feeding window.
Introduction: The probiotic Bacillus coagulans (GanedenBC30) has been shown to support healthy digestive and immune function. A recent pilot study in athletes indicated that co-ingestion of GanedenBC30 with a slow digesting protein during an 8-week full body workout increased performance in resistance trained athletes. We speculate that GanedenBC30's beneficial effects might be based on aiding muscle recovery through gut microbial modulation. Purpose: This pilot study investigated the impact of GanedenBC30 (GBI-30, 6086; Ganeden Biotech Inc., Maryfield Heights, OH, USA) supplementation on recovery, markers of muscle damage, and muscle performance following a muscle-damaging bout. Methods: Three recreationally active male subjects deprived of previous resistance-training experience were recruited to take part in a randomized, cross-over, double blind design. On day 0, subjects reported to the laboratory for baseline measurements (1RM Single Leg Leg-Press [1RM LP], Wingate Peak Power [WPP], Vertical Jump Peak Power [VJPP], Vastus Lateralis Thickness [MT], Creatine Kinase [CK] and Blood Urea Nitrogen [BUN]). Subjects administered either 20 g of casein (Control = CON) or 20 g of casein plus probiotic (500M BC30, = BC30) twice daily for the following 18 days. On day 14, subjects underwent an intense single-leg training bout designed to create muscle damage. At 24, 48, and 72 hours after the training bout Perceived Recovery (PR) and Perceived Soreness (PS) were measured via analogue scale. At 48 hours post testing, post measures (1RM LP, WPP, VJPP, MT, CK, and BUN) were taken. Subjects underwent 7 days of a wash-out and then crossed-over conditions. An ANOVA with repeated-measures was used to scrutinize the effects of different supplementation on selected-dependent variables (e.g., CK and Wingate power) assuming group (CON and BC30) and time (baseline and post) as fixed factors. Finally, within-group effect sizes (ES = pre-to-post changes/pre-test standard deviation) were calculated for the selected variables. The significance level was previously set at p ≤ 0.05. Results: No significant between group differences were detected at baseline for selected-variables (p > 0.05). The damaging exercise resulted in an increase in CK levels in the CON group (Pre: 157 U·L−1, Post: 1,606 U·L−1, ES: 13.6), however BC30 was able to blunt the increase in CK levels by 54% (Pre: 211 U·L−1, Post: 883 U·L−1, ES: 5.1). WPP decrease in the CON group by −16.1% (Pre: 694.5 Watts, Post: 582.6 Watts, Delta: −111.9 Watts), whereas WPP increased in the BC30 group by 6.9% (Pre: 599.5 Watts, Post: 640.9 Watts, Delta: +41.4 Watts). No significant differences (p > 0.05) were observed between groups in any of the measures due to the small sample size. Conclusions: BC30 administration seems to have a beneficial effect on muscle damage, consequently leading to improved performance thereby providing a strong rationale for conducting a larger study to investigate the effects of this probiotic on muscle recovery and performance. Practical Applications: While further research is needed, large effect size differences between groups indicate that athletes benefit from GanedenBC30 supplementation.
Pre-workout supplements (PWS) have become increasingly popular with recreational and competitive athletes. While many ingredients used in PWS have had their safety assessed, the interactions when combined are less understood. The purpose of this study was to examine the safety of 1 and 2 servings of a PWS. Forty-four males and females (24.4±4.6 years; 174.7±9.3 cm; 78.9±18.6 kg) from two laboratories participated in this study. Subjects were randomly assigned to consume either one serving (G1; n=14) or two servings (G2; n=18) of PWS or serve as an unsupplemented control (CRL; n=12). Blood draws for safety panels were conducted by a trained phlebotomist before and after the supplementation period. Pooled data from both laboratories revealed significant group×time interactions (p<0.05) for mean corpuscular hemoglobin (MCH; CRL: 30.9±0.8-31.0±0.9 pg; G1: 30.7±1.1-30.2±0.7 pg; G2: 30.9±1.2-30.9±1.1 pg), MCH concentration (CRL: 34.0±0.9-34.4±0.7 g/dL; G1: 34.1±0.9-33.8±0.6 g/dL; G2: 34.0±1.0-33.8±0.8 g/dL), platelets (CRL: 261.9±45.7-255.2±41.2×10(3)/µL; G1: 223.8±47.7-238.7±49.6×10(3)/µL; G2: 239.1±28.3-230.8±34.5×10(3)/µL), serum glucose (CRL: 84.1±5.2-83.3±5.8 mg/dL; G1: 86.5±7.9-89.7±5.6 mg/dL; G2: 87.4±7.2-89.9±6.6 mg/dL), sodium (CRL: 137.0±2.7-136.4±2.4 mmol/L; 139.6±1.4-140.0±2.2 mmol/L; G2: 139.0±2.2-138.7±1.7 mmol/L), albumin (CRL: 4.4±0.15-4.4±0.22 g/dL; G1: 4.5±0.19-4.5±0.13 g/dL; G2: 4.6±0.28-4.3±0.13 g/dL), and albumin:globulin (CRL: 1.8±0.30-1.8±0.28; G1: 1.9±0.30-2.0±0.31; G2: 1.8±0.34-1.8±0.34). Each of these variables remained within the clinical reference ranges. The PWS appears to be safe for heart, liver, and kidney function in both one-serving and two-serving doses when consumed daily for 28 days. Despite the changes observed for select variables, no variable reached clinical significance.
Introduction The probiotic GanedenBC30 (Bacillus coagulans GBI-30, 6086; Ganeden Biotech Inc., Maryfield Heights, OH) has been shown to support healthy digestive and immune function, including increased protein absorption. In a pilot study, daily co-administration of GanedenBC30 and protein in resistance-trained subjects performing full body workouts 4 times per week for 8 weeks has shown a trend to increase vertical jump power and might have a beneficial effect on peak power and fat mass. We speculate that the beneficial effects might be based on aiding muscle recovery through gut microbial modulation. Thus, the purpose of this investigation was to determine if the co-administration of GanedenBC30 with protein has a beneficial effect on muscle damage, recovery and athletic performance following a damaging exercise bout. Methods 30 healthy recreationally-trained males participated in this study (mean+/-SD; age: 21.5 ± 2.8 years; height: 177.4 ± 8.0 cm; weight: 89.7 ± 28.2 kg). Subjects were randomly assigned to consume either 20 g of casein (Control = CON) or 20 g of casein plus probiotic (500M CFU GanedenBC30, = BC30) twice daily in a crossover, diet-controlled design for a two-week time period. Subjects performed a damaging exercise bout consisting of 10 sets × 10 repetitions unilateral leg press at 70% 1 RM with 1 minute rest, one legged - leg extension (5 sets × 12 reps), and rear foot elevated split squat 5 sets × 12 reps with one minute rest at baseline and after two weeks of supplementation. Athletic performance consisting of peak power (Wingate 10 sec Peak Power Assessment at 7.5% BW at 175RPM threshold loaded drop), vertical jump power (Tendo unit, single-leg jump), and 1-RM single-leg press; and muscle damage was analyzed by muscle swelling (ultrasonography) and blood draws (creatine kinase (CK), blood urea nitrogen (BUN)) were taken at baseline (pre-supplementation) and 48 hours after damaging exercise bout. Perceptual measures (perceived recovery, soreness) were taken before, 24, 48 and 72 hours after exercise. Results The damaging exercise bout significantly increased muscle soreness (p < 0.001), reduced perceived recovery (p < 0.001), however, BC30 significantly increased recovery at 24 and 72 hours, and decreased soreness at 72 hours post exercise in comparison to CON. Perceptual measures were confirmed by increases in CK (CON: +266.8%, p = 0.0002; BC30: +137.7%, p = 0.01), with BC30 showing a trend towards reduced indices of muscle damage (p = 0.08). The strenuous exercise significantly reduced athletic performance in CON (Wingate Peak Power; CON: (-39.8 watts, - 5.3%, p = 0.03)), whereas BC30 maintained performance by (+10.1 watts, +1.7%). There were no differences between groups for strength responses (CON: +7.2 kg, +2.6%, p = 0.15; and BC30: +3.4 kg, +1.2%, p = 0.79). Conclusions This study indicated that probiotic supplementation in form of GanedenBC30 in combination with protein (casein) reduces indices of muscle damage, increases recovery and may maintain athletic performance after muscle damaging exercise.
Background Whey protein is considered to be the optimal protein source to support muscle protein synthesis (MPS) with resistance training, based on its amino acid content (high in leucine), rapid digestibility, and high bioavailability within the muscle tissue . Athletes can choose from different plant protein sources (e.g. soy, rice, pea, hemp), which differ in numerous ways, such as the presence of allergens (milk, soy), cholesterol, saturated fats, digestion rate (fast, intermediate, or slow absorption of amino acids), or the relative amount of individual amino acids. Rice protein has been shown to promote muscle hypertrophy with resistance training comparable to whey protein . 48g of rice or whey protein isolate immediately post-exercise during an 8-week progressive, non-linear resistance-training protocol increased lean body mass, muscle thickness, and strength with no differences between groups. The findings are likely due to the high dose of protein used in the study, providing amounts of leucine greater than the 1.7 to 3.5g that has been proposed to be the range for optimal MPS. Rice protein, compared to whey (fast) and casein (slow), is an intermediate digesting protein and shows a 6.8% lower total amino acid appearance in the blood . While dairy protein sources contain simple sugars, mainly lactose, plant proteins contain more complex carbohydrates, including fibers and glycoproteins. This study sought to investigate if co-ingestion of a plant protein specific digestive enzyme blend (Digest-All® VP, a proprietary enzyme blend consisting of protease 6.0, protease 4.5, peptidase, bromelain and alpha-galactosidase, Chemi-Source, Inc., Oceanside, CA) can reduce the significant differences in amino acid appearance in the blood between plant and animal proteins. Methods After a 12 hour overnight fast, 11 resistance-trained male subjects (age: 21.4 ± 1.5 years, body weight: 82.5 ± 3.9kg, height: 177.3cm ± 6.1cm, and average training status of 2.3 years ± 1.9 years) were randomly assigned to receive either 60 grams of whey protein concentrate ("WPC", Milk Specialties Global, Eden Prairie, MN), or a 70:30 blend of pea protein (VegOtein® P80, Axiom Foods, Los Angeles, CA) and rice protein (Oryzatein® Silk 80, Axiom Foods, Los Angeles, CA) concentrate ("PRPC"), or PRPC plus Digest-All® VP ("PRPC+DA", Veggie Elite®, MRM, Oceanside, CA) in a double-blind, crossover design, separated by a washout period of 7 days. Blood draws were taken immediately prior to, and at 30 minutes, 1, 2, 3, and 4 hours following consumption of WPC, PRPC or PRPC+DA. Results Time to peak (Tmax (min)) for total amino acid (TAA) was faster in the WPC group in comparison to PRPC. However, the addition of digestive enzymes to the plant protein blend increased Tmax of PRPC+DA over WPC (TAA: WPC 62.7 ± 31.3, PRPC 73.6 ± 33.6, PRPC+DA 57.3 ± 24.9). Tmax for the sum of non-essential amino acids (NEAA) showed the same trend: WPC 62.7 ± 31.3, PRPC 73.6 ± 31.1, PRPC+DA 51.8 ± 24.9, while for essential amino acids (EAA) WPC was fastest: WPC 57.3 ± 9.0, PRPC 76.4 ± 28.0, PRPC+DA 70.9 ± 24.3. There were no differences between conditions for Tmax (p = 0.10). Significant differences were detected for AUC (AUC × 103 [nmol/ml]) whereas the EAA for PRPC 384.5 ± 79.3 was significant lower than WPC 447.1 ± 69.9 (p = 0.002). There were no differences for the AUC between WPC and PRPC+DA 404.9 ± 80.5 (p = 0.16). In addition, no significant differences between conditions were detected for NEAA: WPC 677.5 ± 145.0, PRPC 650.3 ± 192.1, PRPC+DA 643.2 ± 139.8, p = 0.59 and for TAA: WPC 1,187.2 ± 228.3, PRPC 1,071.0 ± 241.0, PRPC+DA 1,083.7 ± 223.0, p = 0.09. There were significant differences between conditions for peak values (Cmax [nmol/ml]) for EAA, whereas WPC (2,261.1 ± 437.2) demonstrated higher values than PRPC (1,797.1 ± 333.4), p = 0.01. There no differences between WPC and PRPC+DA (1,881.4 ± 352.9), p = 0.07. No significance differences in Cmax were found for NEAA (WPC 3,103.4 ± 769.8, PRPC 2,978.2 ± 663.8, PRPC+DA 2,904.8 ± 726.7, p = 0.94) and TAA (WPC 5,694.1 ± 1,317.7, PRPC 4,940.5 ± 951.9, PRPC+DA 4,936.6 ± 1,231.0, p = 0.62). Conclusion Co-ingestion of a plant protein specific digestive enzyme blend (Digest-All® VP) and a pea/rice protein blend increases time to peak, peak concentrations, and amount of amino acid appearance in the blood (AUC) in comparison to pea/rice protein alone, and reduces previously significant differences between WPC and PRPC.
Abstract There has been much debate as to optimal loading strategies for maximising the adaptive response to resistance exercise. The purpose of this paper therefore was to conduct a meta-analysis of randomised controlled trials to compare the effects of low-load (≤60% 1 repetition maximum [RM]) versus high-load (≥65% 1 RM) training in enhancing post-exercise muscular adaptations. The strength analysis comprised 251 subjects and 32 effect sizes (ESs), nested within 20 treatment groups and 9 studies. The hypertrophy analysis comprised 191 subjects and 34 ESs, nested with 17 treatment groups and 8 studies. There was a trend for strength outcomes to be greater with high loads compared to low loads (difference = 1.07 ± 0.60; CI: -0.18, 2.32; p = 0.09). The mean ES for low loads was 1.23 ± 0.43 (CI: 0.32, 2.13). The mean ES for high loads was 2.30 ± 0.43 (CI: 1.41, 3.19). There was a trend for hypertrophy outcomes to be greater with high loads compared to low loads (difference = 0.43 ± 0.24; CI: -0.05, 0.92; p = 0.076). The mean ES for low loads was 0.39 ± 0.17 (CI: 0.05, 0.73). The mean ES for high loads was 0.82 ± 0.17 (CI: 0.49, 1.16). In conclusion, training with loads ≤50% 1 RM was found to promote substantial increases in muscle strength and hypertrophy in untrained individuals, but a trend was noted for superiority of heavy loading with respect to these outcome measures with null findings likely attributed to a relatively small number of studies on the topic.
Creatine monohydrate has become a very popular nutritional supplement for its ergogenic effects. The safety of creatine monohydrate has previously been confirmed. However with each novel form of creatine that emerges, its safety must be verified. Therefore, the purpose of this study was to examine the safety of a novel form of creatine, creatine nitrate (CN), over a 28 day period. 58 young males and females (Pooled: 24.3 ± 3.9 years, 144.9 ± 8.0 cm, 74.2 ± 13.0 kg) participated in this study across two laboratories. Subjects were equally and randomly assigned to consume either 1 g (n = 18) or 2 g (n = 20) of CN or remained unsupplemented (n = 20). Blood draws for full safety panels were conducted by a trained phlebotomist prior to and at the conclusion of the supplementation period. Pooled data from both laboratories revealed significant group x time interactions for absolute lymphocytes and absolute monocytes (p < 0.05). Analysis of the 1 g treatment revealed lab x time differences for red blood cell distribution width, platelets, absolute monocytes, creatinine, blood urea nitrogen (BUN):creatinine, sodium, protein, and alanine aminotransferase (ALT) (p < 0.05). Analysis of the 2 g treatment revealed lab x time differences for BUN:creatinine and ALT (p < 0.05). BUN and BUN:creatinine increased beyond the clinical reference range for the 2 g treatment of Lab 2, but BUN did not reach statistical significance. Overall, CN appears to be safe in both 1 g and 2 g servings daily for up to a 28 day period. While those with previously elevated BUN levels may see additional increases resulting in post-supplementation values slightly beyond normal physiological range, these results have minor clinical significance and are not cause for concern. Otherwise, all hematological safety markers remained within normal range, suggesting that CN supplementation has no adverse effects in daily doses up to 2 g over 28 days and may be an alternative to creatine monohydrate supplementation.
In spite of the well-known benefits that have been shown, few studies have looked at the practical applications of high-intensity interval training (HIIT) on athletic performance. This study investigated the effects of a HIIT program compared to traditional continuous endurance exercise training. 24 hockey players were randomly assigned to either a continuous or high-intensity interval group during a 4-week training program. The interval group (IG) was involved in a periodized HIIT program. The continuous group (CG) performed moderate intensity cycling for 45–60 min at an intensity that was 65% of their calculated heart rate reserve. Body composition, muscle thickness, anaerobic power, and on-ice measures were assessed pre- and post-training. Muscle thickness was significantly greater in IG (p=0.01) when compared to CG. The IG had greater values for both ∆ peak power (p<0.003) and ∆ mean power (p<0.02). Additionally, IG demonstrated a faster ∆ sprint (p<0.02) and a trend (p=0.08) for faster ∆ endurance test time to completion for IG. These results indicate that hockey players may utilize short-term HIIT to elicit positive effects in muscle thickness, power and on-ice performance.
Background: This study investigated comparative concentrations of individual amino acids, total amino acids (TAA), non-essential amino acids (NEA) and essential amino acids (EAA) in the blood after the administration of Rice Protein Isolate (RPI) compared to Whey Protein Isolate (WPI). Methods: After a 12 hour overnight fast, 10 trained male subjects were randomly assigned to receive either 48 grams of RPI or WPI in a double-blind, crossover design, separated by a washout period of 7 days. Blood draws were taken immediately prior to, and at 1, 2, 3, and 4 hours following consumption of WPI or RPI. Pharmacokinetic parameters of plasma concentrations of amino acids were analyzed by a repeated measures ANOVA. AUC0-t, and Cmax were analyzed by t-tests. Results: WPI and RPI showed a significant difference between Tmax for essential amino acids (EAA: RPI 87 ± 7 min, WPI 67 ± 4 min, p=0.03), non-essential amino acids (NEA: RPI 97 ± 4 min, WPI 71 ± 5 min, p<0.001), and total amino acids (TA: RPI 93 ± 4 min, WPI 69 ± 3 min, p<0.001), however no significant differences were detected for AUC (EAA: RPI 649.5 ± 140.9 nmol/ml, WPI 754.2 ± 170.0 nmol/ml, p=0.64; NEA: RPI 592.7 ± 118.2 nmol/ml, WPI 592.7 ± 121.2 nmol/ml, p=0.98; TAA: RPI 615.9 ± 88.6 nmol/ml, WPI 661.1 ± 98.7 nmol/ml, p=0.74), and neither for Cmax (EAA: RPI 176.1 ± 37.5 nmol/ml, WPI 229.5 ± 51.2 nmol/ml, p=0.41; NEA: RPI 160.0 ± 31.1 nmol/ml, WPI 178.4 ± 34.0 nmol/ml, p=0.69; TA: RPI 166.6 ± 23.4 nmol/ml, WPI 199.3 ± 28.8 nmol/ml, p=0.38). On an individual amino acid basis, WPI was faster or equal for all amino acids with the excpetion of leucine, which reached Cmax faster in the RPI group. Conclusion: While RPI elicited a 6.8% lower total amino acid concentration in the blood based on AUC compared to WPI, the difference was not statistically significant. Future research should investigate additional time points and stable isotope labels to study digestion and effect on whole body net protein synthesis in relation to the used protein.
Unlabelled: This study compared quadriceps muscle cross-sectional area (CSA) and maximum strength (1RM) after three different short-term strength training (ST) regimens (i.e. non-periodized [NP], traditional-periodization [TP], and undulating-periodization [UP]) matched for volume load in previously untrained individuals. Thirty-one recreationally active males were randomly divided into four groups: NP: n = 9; TP: n = 9; UP: n = 8 and control group (C): n = 5. Experimental groups underwent a 6-week program consisting of two training sessions per week. Muscle strength was assessed at baseline and after the training period. Dominant leg quadriceps CSA was obtained through magnetic resonance imaging (MRI) at baseline and 48h after the last training session. Results: The 1RM increased from pre to post only in the NP and UP groups (NP = 17.0 %, p = 0.002; UP = 12.9 %, p = 0.03), respectively. There were no significant differences in 1RM for LP and C groups after 6 weeks (TP = 7.7 %, p = 0.58, C = 1.2 %, p = 1.00). The CSA increased from pre to post in all of the experimental groups (NP = 5.1 %, p = 0.0001; TP = 4.6 %, p = 0.001; UP = 5.2 %, p = 0.0001), with no changes observed in the C group (p = 0.93). Conclusion: Our results suggest that different ST periodization regimens over a short-term (i.e. 6 weeks), volume load equated conditions seem to induce similar hypertrophic responses regardless of the loading scheme employed. In addition, for those recreational males who need to develop muscle strength in the short-term, the training regimen should be designed properly. Key pointsMuscle hypertrophy occurs within six weeks in recreationally active men regardless the ST training regimen employed.When the total volume is similar, training at greater intensities will demonstrate superior gains in the 1RM performance.Some caution should be exercised when interpreting our findings since long-term periodized regimens could produce different training-induced responses.
Background While growing evidence suggests beneficial effects of probiotics on the gut-brain-axis, only a limited number of studies have investigated the impact of gut microbiota modulation on muscle physiology (gut-muscle-axis). The probiotic BC30 (Ganeden Biotech Inc., Maryfield Heights, OH) has been shown to increase protein absorption and the anabolic potential of a respective protein source has been directly linked to peak plasma leucine levels. Post-workout administration of slow digesting proteins such as casein show inferior results on muscle protein synthesis in comparison to fast absorbed proteins such as whey. Thus, the purpose of this investigation was to determine if the co-administration of a probiotic with a slow digested protein has a beneficial effect on body composition, performance, and measures of perceived health. Methods 10 healthy resistance-trained individuals volunteered to participate in this study (mean+/-SD; age: 22.0 ± 2.4 yr; height: 181.8 ± 4.1 cm; weight: 85.6 ± 12.9 kg). Subjects were randomly assigned to consume either 20g of casein (Control = CON) or 20g of casein plus probiotic (500M BC30, =BC30) twice daily. Subjects were instructed to consume one serving in the morning upon waking while the second serving was consumed after training or before bed on non-training days. With assistance from a dietician, macronutrients were controlled to 50% carbohydrate, 25% protein, and 25% fat between groups using the Mifflin-St Jeor formula. Subjects performed full body workouts 4-times per week for 8 weeks consisting of hypertrophy (8-12 RM loads and 60 seconds rest), and strength (1-5 RM loads with 3-5 minutes rest) under supervision of the researchers in order to ensure compliance. Body composition (Dual X-Ray Absorptiometry; DXA), quadriceps thickness (ultrasound), peak power (Monark Wingate Cycle), vertical jump power (Tendo unit), 1-RM bench press, and 1-RM leg press were measured at baseline and after the eighth week of supplementation. Perceived GI health (GSRS) was measured weekly and upper respiratory health (WURSS-21) daily. Consent to publish the results was obtained from all participants. Results BC30 showed a trend (p=0.10) to increase vertical jump power (BC30: pre 2,136 W, post 2,262 W; CON pre 1,712 W, post 1,691 W) and might have a beneficial effect on peak power and fat mass. There were no significant differences between groups for body composition, or other performance measures. Due to an overall very low number of incidences in digestive and immune health in both groups no meaningful analysis could be done. Conclusions This pilot study indicated that probiotic supplementation in form of BC30 in combination with a slow digesting protein might increase athletic performance. However, further research with a larger n-size is needed to confirm these findings.
Background Most pre-workout supplements are based on the stimulant caffeine, containing anywhere from 100-300 mg of caffeine in a serving. While research has confirmed increased mental focus and acuity from the use of caffeine, stimulant sensitive individuals should assess their tolerance before using pre-workout supplements containing caffeine. Caffeine can have dose-dependent unwanted effects contributing to a nervous or anxious feeling that can keep athletes from staying focused and even sleeping well. Ingredients to increase the synthesis and release of neurotransmitters (Tyrosine, acetyl-L-carnitine, alpha-GPC), and blood flow to the brain (Gingko Biloba), offer neuroprotection (blueberry extract), and improve mental regeneration and reduce mental stress (L-Theanine) might offer a stimulant-free alternative to improve pre-workout cognition. Therefore, the purpose of the current study was to investigate the effects of caffeine and a stimulant-free pre-workout formula on alertness (A), focus (F), calmness (CAL), motivation (MOT), cognition (COG), reaction (R), motor reaction time (MR), memory (MEM) and vertical jump power (VJP). Methods Five college-aged males volunteered to participate in this study and were randomly assigned to consume MindSet (Haleo Inc., San Diego, CA), Caffeine, and a placebo (rice flour) in a double-blind, placebo-controlled, randomized, crossover design. After baseline testing, subjects consumed one of the assigned supplements 30 minutes prior to testing. Tests were separated by a 48 hour wash-out period. All subjects participated in a variety of mental aptitude tests, visual reaction tests, and power output measurements. Mental aptitude tests (A, F, CAL, MOT) were measured on an interval scale. COG was measured as serial subtraction test; accounting for improvement in scores from pre and post testing. RT and MRT were measured through the use of Dynavision, and VJP was measured through Vertical Jump Test via Tendo Unit. Consent to publish the results was obtained from all participants. Results Caffeine increased alertness (+19%), focus (+35%), cognition (+26%), memory (+11%), motivation (+10%) and vertical jump power (+1%), however, decreased calmness by 18%. MindSet increased alertness (56%), focus (58%), motivation (43%), cognition (26%), memory (+15%), vertical jump power (3%), and calmness by 6%. Conclusion A stimulant-free multi-ingredient pre-workout formula can be as effective as caffeine in increasing cognitive functioning without the unwanted side-effects. The results of this pilot study should be confirmed in a larger scale study.
Background Human and cell culture studies have demonstrated that phosphatidic acid (PA) can increase muscle mass and anabolic signaling, respectively. However, no in vivo evidence to date has examined whether PA can increase intramuscular anabolic signaling in vivo. The purpose of this study was to examine – a) if PA feeding acutely increases post-prandial muscle protein synthesis (MPS) and anabolic signaling markers; and b) if PA can enhance the post-prandial anabolic effects of whey protein concentrate (WPC). Methods Male Wistar rats (~250 g) were fasted overnight (~18 h) and fed either: a) 1 ml water (n = 14), b) 28 mg PA (eq. to 1.5 g human dose; n = 8), c) 197 mg WPC (eq. to 10 g human dose; n = 8), or d) PA+WPC (n = 8). 2.5 h post-feeding rats were injected with 5.44 mg puromycin diHCl for MPS assessment via SUnSET and 3 hours post-feeding rats were euthanized and mixed gastrocnemius muscles were removed for immunoblotting analyses. The treatment of the animals in this study adhered to commonly accepted ethics guidelines. Results Compared to water-fed rats, PA feeding caused an elevation in numerous Akt-mTOR markers and, in some instances, PA+WPC exhibted a greater increase in Akt-mTOR signaling markers (Erk1/2 Thr202/Tyr204, Bad Ser112, p70s6k Thr389). However, compared to water-fed rats, the PA, WPC, and PA+WPC groups exhibited greater MPS responses with no differences existing between conditions. Conclusion This is the first in vivo data demonstrating that PA feeding increases MPS. More post-prandial time course data with resistance exercise is needed to better elucidate how PA feeding affects muscle anabolism.
Introduction The lipid messenger phosphatidic acid (PA) plays a critical role in the stimulation of mTOR signaling. However, the mechanism by which PA stimulates mTOR is currently unknown. Therefore, the purpose of this study was to compare the effects of various PA precursors and phospholipids on their ability to stimulate mTOR signaling and its ability to augment resistance training-induced changes in body composition and performance. Methods In phase one, C2C12 myoblasts cells were stimulated with different phospholipids and phospholipid precursors derived from soy and egg sources. The ratio of phosphorylated p70 (P-p70-389) to total p70 was then used as readout for mTOR signaling. In phase two, resistance trained subjects (n = 28, 21 ± 3 years, 77 ± 4 kg, 176 ± 9 cm) consumed either 750 mg PA daily or placebo and each took part in an 8 week periodized resistance training program. Results In phase one, soy-phosphatidylserine, soy-Lyso-PA, egg-PA, and soy-PA stimulated mTOR signaling, and the effects of soy-PA (+636%) were significantly greater than egg-PA (+221%). In phase two, PA significantly increased lean body mass (+2.4 kg), cross sectional area (+1.0 cm), and leg press strength (+51.9 kg) over placebo. Conclusion PA significantly activates mTOR and significantly improved responses in skeletal muscle hypertrophy, lean body mass, and maximal strength to resistance exercise.
Introduction Extracellular adenosine triphosphate (ATP) stimulates vasodilation by binding to endothelial ATP-selective P2Y2 receptors; a phenomenon, which is posited to be accelerated during exercise. Herein, we used a rat model to examine how different dosages of acute oral ATP administration affected the femoral blood flow response prior to, during, and after an exercise bout. In addition, we performed a single dose chronic administration pilot study in resistance trained athletes. Methods Animal study: Male Wistar rats were gavage-fed the body surface area, species adjusted human equivalent dose (HED) of either 100 mg (n=4), 400 mg (n=4), 1,000 mg (n=5) or 1,600 mg (n=5) of oral ATP as a disodium salt (Peak ATP(R), TSI, Missoula, MT). Rats that were not gavage-fed were used as controls (CTL, n=5). Blood flow was monitored continuously: a) 60 min prior to, b) during and c) 90 min following an electrically-evoked leg-kicking exercise. Human Study: In a pilot study, 12 college-aged resistance-trained subjects were given 400 mg of ATP (Peak ATP(R), TSI, Missoula, MT) daily for 12 weeks, and prior to an acute arm exercise bout at weeks 1, 4, 8, and 12. Ultrasonography-determined volumetric blood flow and vessel dilation in the brachial artery was measured at rest, at rest 30 minutes after supplementation, and then at 0, 3, and 6 minutes after the exercise. Results Animal Study: Rats fed 1,000 mg HED demonstrated significantly greater recovery blood flow (p < 0.01) and total blood flow AUC values (p < 0.05) compared to CTL rats. Specifically, blood flow was elevated in rats fed 1,000 mg HED versus CTL rats at 20 to 90 min post exercise when examining 10-min blood flow intervals (p < 0.05). When examining within-group differences relative to baseline values, rats fed the 1,000 mg and 1,600 mg HED exhibited the most robust increases in blood flow during exercise and into the recovery period. Human study: At weeks 1, 8, and 12, ATP supplementation significantly increased blood flow, along with significant elevations in brachial dilation. Conclusions Oral ATP administration can increase post-exercise blood flow, and may be particularly effective during exercise recovery.
The potential health benefits of curcumin are limited by its poor solubility, low absorption from the gut, rapid metabolism and rapid systemic elimination. The purpose of this study was the comparative measurement of the increases in levels of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin) and the metabolite tetrahydrocurcumin after oral administration of three different curcumin formulations in comparison to unformulated standard. The relative absorption of a curcumin phytosome formulation (CP), a formulation with volatile oils of turmeric rhizome (CTR) and a formulation of curcumin with a combination of hydrophilic carrier, cellulosic derivatives and natural antioxidants (CHC) in comparison to a standardized curcumin mixture (CS) was investigated in a randomized, double-blind, crossover human study in healthy volunteers. Samples were analyzed by HPLC-MS/MS. Total curcuminoids appearance in the blood was 1.3-fold higher for CTR and 7.9-fold higher for CP in comparison to unformulated CS. CHC showed a 45.9-fold higher absorption over CS and significantly improved absorption over CP (5.8-fold) and CTR (34.9-fold, all p < 0.001). A formulation of curcumin with a combination of hydrophilic carrier, cellulosic derivatives and natural antioxidants significantly increases curcuminoid appearance in the blood in comparison to unformulated standard curcumin CS, CTR and CP.
Resistance training in combination with practical blood flow restriction (pBFR) is thought to stimulate muscle hypertrophy by increasing muscle activation and muscle swelling. Most previous studies used the KAATSU device; however, little long-term research has been completed using pBFR. To investigate the effects of pBFR on muscle hypertrophy. Twenty college-aged male participants with a minimum of 1 year of resistance training experience were recruited for this study. Our study consisted of a randomized, crossover protocol consisting of individuals either using pBFR for the elbow flexors during the first 4 weeks (BFR-HI) or the second 4 weeks (HI-BFR) of an 8-week resistance training programme. Direct ultrasound-determined bicep muscle thickness was assessed collectively at baseline and at the end of weeks 4 and 8. There were no differences in muscle thickness between groups at baseline (P = 0·52). There were time (P<0·01, ES = 0·99) but no condition by time effects (P = 0·58, ES = 0·80) for muscle thickness in which the combined values of both groups increased on average from week 0 (3·66 ± 0·06) to week 4 (3·95 ± 0·05) to week 8 (4·11 ± 0·07). However, both the BFR-HI and HI-BFR increased significantly from baseline to week 4 (6·9% and 8·6%, P<0·01) and from weeks 4 to 8 (4·1%, 4·0%, P<0·01), respectively. The results of this study suggest that pBFR can stimulate muscle hypertrophy to the same degree to that of high-intensity resistance training.
Xpand(R) 2X is a proprietary blend comprised of branched chain amino acids, creatine monohydrate, beta-alanine (CarnoSyn(R)), quercetin, coenzymated B-vitamins, alanyl-glutamine (Sustamine(R)), and natural nitrate sources from pomegranate and beet root extracts purported to enhance the neuromuscular adaptations of resistance training. However to date, no long-term studies have been conducted with this supplement. The purpose of this study was to investigate the effects of a multi-ingredient performance supplement (MIPS) on skeletal muscle hypertrophy, lean body mass and lower body strength in resistance-trained males. Twenty resistance-trained males (21.3 +/- 1.9 years) were randomly assigned to consume a MIPS or a placebo of equal weight and volume (food-grade orange flavors and sweeteners) in a double-blind manner, 30 minutes prior to exercise. All subjects participated in an 8-week, 3-day per week, periodized, resistance-training program that was split-focused on multi-joint movements such as leg press, bench press, and bent-over rows. Ultrasonography measured muscle thickness of the quadriceps, dual-energy X-ray absorptiometry (DEXA) determined lean body mass, and strength of the bench press and leg press were determined at weeks 0, 4, and 8 of the study. Data were analyzed with a 2 x 3 repeated measures ANOVA with LSD post hoc tests utilized to locate differences. There was a significant group-by-time interaction in which the MIPS supplementation resulted in a significant (p < 0.01) increase in strength of the bench press (18.4% vs. 9.6%) compared with placebo after 4 and 8 weeks of training. There were no significant group by time interactions between MIPS supplementation nor the placebo in leg press strength (p = .08). MIPS supplementation also resulted in a significant increase in lean body mass (7.8% vs. 3.6%) and quadriceps muscle thickness (11.8% vs. 4.5%) compared with placebo (group*time, p <0.01). These results suggest that this MIPS can positively augment adaptations in strength, and skeletal muscle hypertrophy in resistance-trained men.
Currently, there is a lack of studies examining the effects of adenosine-5'-triphosphate (ATP) supplementation utilizing a long-term, periodized resistance-training program (RT) in resistance-trained populations. Therefore, we investigated the effects of 12 weeks of 400 mg per day of oral ATP on muscular adaptations in trained individuals. We also sought to determine the effects of ATP on muscle protein breakdown, cortisol, and performance during an overreaching cycle. The study was a 3-phase randomized, double-blind, and placebo- and diet-controlled intervention. Phase 1 was a periodized resistance-training program. Phase 2 consisted of a two week overreaching cycle in which volume and frequency were increased followed by a 2-week taper (Phase 3). Muscle mass, strength, and power were examined at weeks 0, 4, 8, and 12 to assess the chronic effects of ATP; assessment performance variables also occurred at the end of weeks 9 and 10, corresponding to the mid and endpoints of the overreaching cycle. There were time (p<0.001), and group x time effects for increased total body strength (+55.3 ± 6.0 kg ATP vs. + 22.4 ± 7.1 kg placebo, p<0.001); increased vertical jump power (+ 796 ± 75 ATP vs. 614 ± 52 watts placebo, p<0.001); and greater ultrasound determined muscle thickness (+4.9 ± 1.0 ATP vs. (2.5 ± 0.6 mm placebo, p<0.02) with ATP supplementation. During the overreaching cycle, there were group x time effects for strength and power, which decreased to a greater extent in the placebo group. Protein breakdown was also lower in the ATP group. Our results suggest oral ATP supplementation may enhance muscular adaptations following 12-weeks of resistance training, and prevent decrements in performance following overreaching. No statistically or clinically significant changes in blood chemistry or hematology were observed. ClinicalTrials.gov NCT01508338.
When health professionals measure the fitness levels of clients, body composition is usually estimated. In field settings, body composition is commonly estimated with skinfolds or bioelectrical impedance analysis. Recently, a portable ultrasound device has been manufactured to estimate what percentage of body mass is composed of adipose tissue (AT%). A reported advantage of using ultrasound is that inter- and intrarater variations may be minimized when compared with the skinfold technique. Therefore, the purpose of this pilot study was twofold; 1) to determine the validity of a portable ultrasound device compared with skinfolds and 2) determine the reliability of the portable ultrasound device. Participants had their measurements taken in the following order: urine specific gravity, body mass, height, skinfolds and ultrasound determined. Participants had their urine specific gravity and ultrasound determined AT% estimates measured again 48 h later. The current pilot study found that the ultrasound was not a valid estimate of AT% when compared with the skinfold estimate (TE > 4%). In addition, the 1-site estimate from the ultrasound was more reliable than the 3-site estimate of AT%. These data are of importance to practitioners because it demonstrates that while the ultrasound is not a valid estimate compared with skinfolds, the 1-site estimate may be able to track changes in AT% over time, making the ultrasound an option for assessing changes in body composition.
Background: Consumption of moderate amounts of animal-derived protein has been shown to differently influence hypertrophy during resistance training when compared with isonitrogenous and isoenergetic amounts of plant-based protein. Objective: We aimed to determine if high doses of rice protein isolate could increase recovery and elicit adequate changes in body composition compared to whey protein isolate if given following periodized resistance-training. Design: 24 college-aged, resistance trained males were recruited for this study. Subjects were randomly and equally divided into two groups, either consuming 48g of rice or whey protein isolate on training days. Subjects trained 3 days per week for 8 weeks as a part of a daily undulating periodized resistance-training program. The rice and whey protein supplements were isocaloric and isonitrogenous, and they were consumed immediately following exercise. Ratings of perceived recovery, soreness, and readiness to train were recorded prior to and following the first training session. Ultrasonography determined muscle thickness, dual emission x-ray absorptiometry, and bench press and leg press strength were recorded during weeks 0, 4, and 8. Results: No detectable differences were present in psychological scores of perceived recovery, soreness, or readiness to train (p>0.05). Significant time effects were observed in which lean body mass, muscle mass, strength and power all increased and fat mass decreased; however, no condition by time interactions were observed (p>0.05). Conclusion: Rice protein isolate administration post resistance exercise decreases fat-mass and increases lean body mass, skeletal muscle hypertrophy, power and strength comparable to whey protein isolate.
Consumption of moderate amounts of animal-derived protein has been shown to differently influence skeletal muscle hypertrophy during resistance training when compared with nitrogenous and isoenergetic amounts of plant-based protein administered in small to moderate doses. Therefore, the purpose of the study was to determine if the post-exercise consumption of rice protein isolate could increase recovery and elicit adequate changes in body composition compared to equally dosed whey protein isolate if given in large, isocaloric doses.
Background The glycerophospholipid Phosphatidic acid (PA) has been identified as a potential nutritional treatment for gastrointestinal disorders. Dietary food sources rich in PA include cabbage and radish leaves as well as Mallotus japonicas, a Japanese edible herb historically used for the treatment of stomach ulcers. The mammalian target of rapamycin (mTOR) has been shown to regulate rates of muscle protein synthesis and a mechanical stimulus (resistance exercise) has been shown to activate mTOR with PA playing a key role. Supplementation with soy-derived PA significantly increases responses in skeletal muscle hypertrophy, lean body mass, and maximal strength to resistance exercise. PA accounts for less than 0.1% of the total glycerophospholipid concentration of 201 mg/dl in the human plasma. 15 of the more than 600 distinct molecular lipid species quantified in human plasma are PA, 6 are lysophosphatidic acid (LPA). Orally administered PA can be metabolized to LPA and glycerophosphate by pancreatic phospholipases A1 and A2, which hydrolyze the fatty acid at the sn-1 position and the sn-2 position, respectively. Lysophospholipids are absorbed by the mucosal cells of the gastrointestinal tract and are rapidly re-acylated with fatty acids of the body pool resulting in a newly-formed phospholipid-molecule whose fatty acid composition is determined by the physiological and nutritional status and not by its source. This study sought to assess the effect of soy-derived PA supplementation on concentrations LPA and PA molecular species in human plasma. Methods After a 12 hour overnight fast one subject (20 years of age, bodyweight of 82 kg, and height of 178 cm) was assigned to receive 1.5 grams of soy-derived PA (Mediator, Chemi Nutra, White Bear Lake, MN). Blood draws were taken immediately prior to, and at 30 min, 1, 2, 3, and 7 hours following supplementation. The samples were analyzed by an ultra-performance liquid chromatograph with triple quadrupole mass spectrometry (LC/MS/MS) using 17:1-LPA and 37:4-PA as internal standards to determine the concentration of LPA and PA molecular species in human plasma. Results At baseline, 19 PA (highest concentrations: C34:2 (15%), C40:4 (11%), and C36:4 (10%)) and 5 LPA (16:0 (45%), 18:2 (19%), 20:4 (17%), 14:0 (11%) and 18:1 (8%)) molecular species could be quantified with total concentrations of PA of 2.66 nmol/ml, and LPA of 0.11 nmol/ml. Plasma concentrations of PA peaked at 3 hours (+32%) after ingestion and stayed elevated even after 7 hours (+18%). LPA showed a bimodal absorption kinetic with peaks after 1 hour (+500%) and 3 hours (+264%), after almost dropping back to baseline levels after 2 hours. On an individual fatty acid level, most prominent was a 23-fold increase in 20:4-LPA after 1 hour compared to baseline. The increase in 20:4-LPA does not result from the administration of PA, since soy-derived PA does not contain any arachidonic acid (fatty acids distribution of soy-PA: 18:2 (66.1%), 18:1 (12.6%), 16:0 (11.7%), 18:3 (6.1%) and 18:0 (3.4%)). Absorption of soy-derived PA must yield glycerophosphate which is re-acylated with arachidonic acid. Conclusion LPA and PA can be molecularly identified and measured. LPA, PA and LPA+PA plasma levels increase 30 min after ingestions, plateau at 1-3 hours and remain above baseline levels after 7 hours. This is the first case study showing that orally administered PA is bioavailable. Future research should repeat this case study with a larger n-size and include the analysis of omega 3 fatty acid-LPA molecular species.
Introduction Adenosine-Triphosphate (ATP) supplementation maintains performance and increases volume under high fatiguing contractions. However, greater fatigue increases recovery demands between training sessions. Studies utilizing HMB free acid (HMB-FA) supplementation suggest that the supplement speeds regenerative capacity. However, we are unaware of studies investigating whether synergism exists between the two. Therefore, we investigated the effects of 12 weeks of HMB-FA, ATP, or a combination of the two on lean mass (LBM), strength, and power in trained individuals. We also determined these supplements effects on performance during an overreaching cycle. Methods A 3-phase double-blind, placebo- and diet-controlled intervention study was conducted. Subjects were given either 3g per day of HMB in the free acid form (Metabolic Technologies, Ames, IA), 400mg per day of Peak ATP®(TSI, Missoula, MT), or a combination of the two. Phase 1 consisted of an 8-week periodized resistance-training program; Phase 2 was a 2-week overreaching cycle in which training volume and frequency increased; and Phase 3 was a 2-week taper in which training volume and frequency were decreased. Muscle mass, strength, and power were examined at weeks 0, 4, 8, and 12 to assess the chronic effects of supplementation; and assessment of these was performed at weeks 9 and 10 of the overreaching cycle. Results Supplementation with ATP and HMB-FA increased strength gains over the 12-week study (ATP*time, p < 0.05 and HMB*time, p <0.05, respectively). Strength gains following training were greatest in the HMB-FA+ATP group, followed by the HMB-FA, ATP, and placebo groups respectively. No significant interaction (HMB-FA*ATP*time, p > 0.05) was observed indicating that the HMB and ATP supplementation effects were additive. During the overreaching cycle, strength declined in the placebo (-4.5%) group, but this decline was blunted in both the ATP (-2%) and HMB-FA (-.5 %) groups. Surprisingly, the HMB-FA+ATP group continued to gain strength (+1.2%). Over the 12-weeks of training vertical jump power increased to the greatest extent in the HMB+ATP group, followed by the HMB-FA, ATP, and placebo groups, respectively. The percentage increases in vertical jump power were synergistic with HMB-FA and ATP supplemented in combination (HMB-FA*ATP*time, p < 0.004). Vertical jump power during the overreaching cycle decreased more in the placebo group, 5.0±0.4%, compared with the smaller decreases in vertical jump power for the HMB-FA, ATP, and HMB-FA+ATP supplemented groups, 1.4±0.4, 2.2±0.4, and 2.2±0.5%, respectively, over weeks 9 and 10 (t-test, p < 0.05). Lean body mass was increased in an additive manner by 2.1±0.5, 7.4±0.4, 4.0±0.4, and 8.5±0.8 kg in placebo, HMB-FA, ATP, and HMB-FA+ATP-supplemented participants, respectively (t-test, p < 0.05), and fat percentage only decreased in the HMB supplemented groups. Conclusions Our results suggest that HMB-FA, ATP, and the combination can enhance LBM, and strength, in an additive manner, with power increasing synergistically when HMB-FA and ATP are combined. These supplements also appear to blunt the typically overreaching response seen to high volume, low recovery training cycles.
Introduction The accretion of skeletal muscle tissue can be critical for a varied population including athletes and elderly. Skeletal muscle hypertrophy is largely mediated through increased muscle protein synthesis. The mammalian target of rapamycin (mTOR) has been shown to regulate rates of muscle protein synthesis and a mechanical stimulus (resistance exercise) has been shown to activate mTOR with the phospholipid Phosphatidic Acid (PA) playing a key role. A first pilot study found that oral supplementation with soy-derived PA in athletes undergoing progressive resistance training very likely resulted in greater increases in squat strength and lean mass over the placebo. However, this pilot study was likely underpowered, the workout was not supervised and no direct measures of skeletal muscle hypertrophy were taken. Therefore, the purpose of this study was to investigate the effects of PA on body composition, strength, power and muscular hypertrophy. Methods Twenty-eight resistance trained, male subjects (21 ± 3 years of age, bodyweight of 76 ± 9 kg, and height of 176 cm ± 9 cm) participated in this study. Subjects were equally divided into experimental and control conditions, and each subject took part in an 8 week periodized resistance training program. The resistance training program consisted of two hypertrophy oriented workouts per week and one strength oriented workout per week. The experimental condition (EXP) received 750 mg of soy-derived PA (Mediator™, Chemi Nutra, White Bear Lake, MN), while the control condition (CON) received a visually identical placebo (rice flour). Measurements of DEXA-determined body composition, rectus femoris CSA, 1RM strength, and anaerobic power were taken prior to and following the 8 week training intervention. A 2x2 repeated measures ANOVA was used to determine group, time, and group x time interactions. A Tukey post-hoc was used to locate differences. Results There was a significant group x time effect (p=0.02) for CSA, in which the EXP group increased (+1.01 cm2, ES = 0.92) to a greater extent than the CON group (+0.61 cm2, ES = 0.52). There was a significant group x time effect (p=0.01) for LBM, in which the EXP group (+2.4 kg, ES = 0.42) doubled the effects of resistance training alone (CON +1.2 kg, ES = 0.26). There was a significant group x time effect (p=0.04) for leg press 1RM, in which the EXP group increased to a greater extent (+52.0 kg, ES = 1.2) than the CON group (+32.5 kg, ES = 0.78). There was a trend group x time effect (p=0.06) for fat loss, in which the EXP group decreased body fat to a greater extent than the CON group (-1.3kg vs. -0.5kg). Conclusion Supplementation with soy-derived PA can improve responses in skeletal muscle hypertrophy, lean body mass, and maximal strength.
Background The mammalian target of rapamycin (mTOR) has been shown to regulate rates of muscle protein synthesis, and one novel nutritional activator of mTOR is the phospholipid Phosphatidic Acid (PA). We have recently found that PA supplementation over 8 weeks of resistance training augmented responses in skeletal muscle hypertrophy and strength. However, we are unaware of research investigating the safety of PA in human subjects. Therefore the purpose of this study was to investigate the effects of 8 weeks of 750 mg per day of PA supplementation on safety parameters in healthy college aged males. Methods Twenty-eight healthy, college aged male subjects (21 ± 3 years of age, bodyweight of 76 ± 9 kg, and height of 176 cm ± 9 cm) participated in this study. Subjects were equally divided into experimental and control conditions. The experimental condition (EXP) received 750 mg of soy-derived PA (Mediator™, Chemi Nutra, White Bear Lake, MN), while the control condition (CON) received a visually identical placebo (rice flour). Measures of cardiovascular, kidney, and liver function were analyzed with a full CMP and CBC prior to and 8 weeks following supplementation. This analysis included: total, high density, and low density lipoproteins, blood glucose, blood urea nitrogen, creatinine, eGFR, Na, K, Cl, CO2, Ca, protein, albumin, globulin, albumin:globulin ratio, total bilirubin, alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase. In addition a sample of urine was submitted for analysis of urine specific gravity and pH. A 2x2 repeated measures ANOVA was used to determine group, time, and group x time interactions. A Tukey post-hoc was used to locate differences. Results There were no differences at baseline in blood chemistry and hematology between the CON and EXP supplemented groups. Additionally no differences were observed in urinalysis values between the groups. Moreover no group, or group X time effects were found following 8 weeks of supplementation. Conclusions Soy-derived PA is a safe nutritional supplement for healthy college aged subjects if taken up to a dosage of 750 mg over an eight week period.
Background Athletes have a choice of different animal (e.g. whey, casein, egg, beef, fish) or plant protein (e.g. soy, rice, pea, hemp) sources, which differ in numerous ways such as the presence of allergens (lactose, soy), cholesterol, saturated fats, digestion rate (fast, intermediate, or slow absorption of amino acids), or the relative amount of individual amino acids. While digestibility of rice protein isolate (RPI) in rats has been shown to be inferior to animal protein (87% vs. 97% for casein), administration of 48 grams of RPI following resistance exercise decreased fat-mass and increased lean body mass, skeletal muscle hypertrophy, power and strength comparable to whey protein isolate (WPI). This study sought to investigate the amino acid rate of appearance in the blood of 48 grams of RPI compared to 48 grams of WPI. Methods After a 12 hour overnight fast, 10 subjects (22.2 ± 4.2 years of age, bodyweight of 77.4 ± 0.6 kg, and height of 176.8 cm ± 8.6 cm) were randomly assigned to receive either 48 grams of RPI (Growing Naturals Rice Protein Isolate (Chocolate Power) made with Oryzatein® rice protein, Axiom Foods, Oro Valley, AZ) or WPI (Nutra Bio Whey Protein Isolate (Dutch Chocolate), Middlesex, NJ) in a double-blind, crossover design, separated by a washout phase of 7 days. Blood draws were taken immediately prior to, and at 1, 2, 3, and 4 hours following consumption of WPI or RPI. Results WPI and RPI showed a significant difference for Tmax for essential amino acids (EAA: RPI 87 ± 7 min, WPI 67 ± 4 min, p=0.03), non-essential amino acids (NEA: RPI 97 ± 4 min, WPI 71 ± 5 min, p<0.001), and total amino acids (TA: RPI 93 ± 4 min, WPI 69 ± 3 min, p<0.001), however no significant differences were detected for AUC (EAA: RPI 649.5 ± 140.9 nmol/ml, WPI 754.2 ± 170.0 nmol/ml, p=0.64; NEA: RPI 592.7 ± 118.2 nmol/ml, WPI 592.7 ± 121.2 nmol/ml, p=0.98; TA: RPI 615.9 ± 88.6 nmol/ml, WPI 661.1 ± 98.7 nmol/ml, p=0.74), and Cmax (EAA: RPI 176.1 ± 37.5 nmol/ml, WPI 229.5 ± 51.2 nmol/ml, p=0.41; NEA: RPI 160.0 ± 31.1 nmol/ml, WPI 178.4 ± 34.0 nmol/ml, p=0.69; TA: RPI 166.6 ± 23.4 nmol/ml, WPI 199.3 ± 28.8 nmol/ml, p=0.38). On an individual amino acid basis, WPI and RPI showed bioequivalency (0.80-1.25 of the geometric mean ratio (GMR)) for AUC and Cmax for all amino acids with the exception of cystine, isoleucine, leucine, lysine, and threonine, in which WPI performed significantly better. Tmax differed between WPI and RPI for histidine, phenylalanine, threonine, asparagine, glutamic acid, glycine, ornithine, proline, and serine. Conclusion These findings suggest that RPI, compared to WPI (fast) and casein (slow), is an intermediate digesting protein. While RPI showed a 6.8% lower total amino acid appearance in the blood based on AUC, the difference was not statistically significant. Future research should investigate the digestion kinetics of RPI for longer periods of time, potentially reducing the observed difference in total amino acid appearance in the blood due to the difference in digestion rates of WPI (fast) and RPI (intermediate). In addition, the potential nutritional effects of the significant differences in absorption of some of the individual amino acids, based on different amino acid content and absorption kinetics of the protein sources, warrants further research.
Introduction Extracellular adenosine triphosphate (ATP) is hypothesized to stimulate vasodilation by binding to endothelial ATP/UTP-selective P2Y2 receptors; a phenomenon which is posited to be accelerated during exercise. Nonetheless, no studies to our knowledge have delineated if supplemental ATP enhances the blood flow response to exercise. Herein, we used a rat model to examine how different dosages of acute oral ATP administration affected the femoral blood flow response prior to, during, and after an exercise bout. In addition, we performed a single dose chronic administration study in resistance trained athletes. Methods Animal study: After anesthesia male Wistar rats (~ 300 g) were placed under isoflurane anesthesia and subsequently gavage-fed either 0.003 g (100 mg, species and body surface area-adjusted human equivalent dosage, n=4), 0.012 g (400 mg, n=4), 0.031 g (1,000 mg, n=5), or 0.049 g (1,600 mg, n=5) of crystallized oral ATP disodium salt (Peak ATP®, TSI, Missoula, MT); rats that were not gavage-fed were used as controls (n=5). A blood flow probe was placed on the proximal portion of the right femoral artery and stimulation electrodes were placed in the right gastrocnemius muscle for an electrically-evoked plantarflexion exercise bout. Blood flow was then monitored continuously: a) 60 min prior to an electrically-evoked leg-kicking exercise (180 contractions), b) during and c) 90 min following the leg-kicking exercise. Areas under the pre-exercise, exercise, post-exercise, and total blood flow curves (AUC) were compared among conditions using one-way ANOVAs. Human Study: In a pilot study, 12 college-aged resistance-trained participants were randomly assigned to an ATP or no ATP group. During week one, subjects were given no ATP, and 400 mg of ATP daily for 12 weeks, and prior to an acute arm exercise bout (60 biceps curl contractions) at weeks 1, 4, 8, and 12. Ultrasonography determined volumetric blood flow and vessel dialation in the brachial artery was measured at rest before taking the supplement and 30 minutes after at rest, and then at 0, 3, and 6 minutes after the exercise. Results Animal Study: Rats fed 0.031 g (1000 mg human equivalent dosage) demonstrated significantly greater recovery blood flow (p = 0.007) and total blood flow AUC values (p = 0.048) compared to CTL rats. Specifically, blood flow was elevated in rats fed 0.031 g versus CTL rats at 20 to 90 min post exercise when examining 10-min blood flow intervals (p < 0.05). When examining within-group differences relative to baseline values, rats fed the 0.031 g (1,000 mg) and 0.049 g (1,600 mg) dosages exhibited the most robust increases in blood flow during exercise and into the recovery period. Human study: At weeks 1, 8, and 12 there were significant differences in blood flow at 0, and 3 minutes post exercise in the ATP supplemented relative to the control week (wk 0-No ATP), along with significant elevations in brachial dilation at those time points. Conclusions These are the first data to our knowledge to demonstrate that oral ATP administration can increase blood flow, and is particularly effective during exercise recovery.
Variable resistance training has recently become a component of strength and conditioning programs. Prior research has demonstrated increases in power and/or strength using low loads of variable resistance. However, no study has examined using high loads of variable resistance as a part of a periodized training protocol. PURPOSE:: to examine variable resistance training within the context of a periodized training program, and to examine a greater load of variable resistance than has been examined in prior research. METHODS:: 14 NCAA Division II male basketball players were recruited for this study. Athletes were divided equally into either a variable resistance or control group. The variable resistance group added 30% of their one repetition maximum as band tension to their prescribed weight one session per week. Rate of power development, peak power, strength, body composition, and vertical jump height were measured pre and post treatment. RESULTS:: No baseline differences were observed between groups for any measurement of strength, power, or body composition. A significant group by time interaction was observed for RPD, in which RPD was greater in VRT post training than in the control group. Significant time effects were observed for all other variables including squat 1RM, bench press 1RM, deadlift 1-RM, clean 3-RM, vertical jump, and lean mass. While there were no significant group X time interactions, the VRT group's percent changes and ESs indicate a larger treatment effect in the squat and bench press 1RM values and the vertical jump performed on the force plate and vertec. CONCLUSIONS:: These results suggest that when using variable resistance as a component of a periodized training program, power and strength can be enhanced. Therefore, athletes whom add variable resistance to one training session per week may enhance their athletic performance.
- May 2013
When health professionals measure the fitness levels of clients, body composition is usually estimated. In practice, the reliability of the measurement may be more important than the actual validity, as reliability determines how much change is needed to be considered meaningful. Therefore, the purpose of this study was to determine the reliability of two bioelectrical impedance analysis (BIA) devices (in athlete and non-athlete mode) and compare that to 3-site skinfold (SKF) readings. Twenty-one college students attended the laboratory on two occasions and had their measurements taken in the following order: body mass, height, SKF, Tanita body fat-350 (BF-350) and Omron HBF-306C. There were no significant pairwise differences between Visit 1 and Visit 2 for any of the estimates (P>0·05). The Pearson product correlations ranged from r = 0·933 for HBF-350 in the athlete mode (A) to r = 0·994 for SKF. The ICC's ranged from 0·93 for HBF-350(A) to 0·992 for SKF, and the MD's ranged from 1·8% for SKF to 5·1% for BF-350(A). The current study found that SKF and HBF-306C(A) were the most reliable (<2%) methods of estimating BF%, with the other methods (BF-350, BF-350(A), HBF-306C) producing minimal differences greater than 2%. In conclusion, the SKF method presented with the best reliability because of its low minimal difference, suggesting this method may be the best field method to track changes over time if you have an experienced tester. However, if technical error is a concern, the practitioner may use the HBF-306C(A) because it had a minimal difference value comparable to SKF.
Wilson, JM, Duncan, NM, Marin, PJ, Brown, LE, Loenneke, JP, Wilson, SMC, Jo, E, Lowery, RP, and Ugrinowitsch, C. Meta-analysis of postactivation potentiation and power: Effects of conditioning activity, volume, gender, rest periods, and training status. J Strength Cond Res 27(3): 854–859, 2013—There is no clear agreement regarding the ideal combination of factors needed to optimize postactivation potentiation (PAP) after a conditioning activity. Therefore, a meta-analysis was conducted to evaluate the effects of training status, volume, rest period length, conditioning activity, and gender on power augmentation due to PAP. A total of 141 effect sizes (ESs) for muscular power were obtained from a total of 32 primary studies, which met our criteria of investigating the effects of a heavy preconditioning activity on power in randomized human trials. The mean overall ES for muscle power was 0.38 after a conditioning activity (p < 0.05). Significant differences were found between moderate intensity (60–84%) 1.06 and heavy intensity (>85%) 0.31 (p < 0.05). There were overall significant differences found between single sets 0.24 and multiple sets 0.66 (p < 0.05). Rest periods of 7–10 minutes (0.7) after a conditioning activity resulted in greater ES than 3–7 minutes (0.54), which was greater than rest periods of >10 minutes (0.02) (p < 0.05). Significant differences were found between untrained 0.14 and athletes 0.81 and between trained 0.29 and athletes. The primary findings of this study were that a conditioning activity augmented power output, and these effects increased with training experience, but did not differ significantly between genders. Moreover, potentiation was optimal after multiple (vs. single) sets, performed at moderate intensities, and using moderate rest periods lengths (7–10 minutes).
- Jan 2013
Currently no research has investigated the relationship between muscle damage, hormonal status, and perceived recovery scale (PRS). Therefore, the purpose of this study was to determine the effects of a high volume training session on PRS and to determine the relationship between levels of testosterone, cortisol and creatine kinase (CK) and PRS. Thirty-five trained subjects (21.3 ± 1.9 years) were recruited. All subjects participated in a high volume resistance training session consisting of 3 sets of full squats, bench press, deadlifts, pullups, dips, bent over rows, shoulder press, and barbell curls and extensions. Pre and post PRS scale measurements (0-10), soreness, creatine kinase (CK), cortisol, and testosterone were measured prior to and 48 hours following training. PRS declined from 8.6 ± 2.3 to 4.2 ± 1.85 (p < 0.05). Leg, chest, and arm soreness increased from pre to post exercise. Creatine kinase significantly increased from pre to post workout (189.4 ± 100.2 to 512 ± 222.7 U/L). Cortisol, testosterone, and free testosterone did not change. There was an inverse relationship between CK and PRS (r=0.58, p < 0.05). When muscle damage was low prior to training, cortisol, free and total testosterone were not correlated to PRS. However, when damage peaked at 48 hours post exercise, free, but not total testosterone, showed a low, direct relationship with PRS (r=0.2, p < 0.05). High volume resistance exercise lowers PRS scores. These changes are partly explained by a rise in serum indices of muscle damage. Moreover, free testosterone appears to have a positive relationship to PRS.
JM. The effects of potentiating stimuli intensity under varying rest periods on vertical jump performance and power. J Strength Cond Res 26 (12): 3320–3325, 2012—Previous research has demonstrated that post-activation potentiation (PAP) increases in an inten-sity-dependent manner. However, these studies did not control for volume loads. The purpose of this study was to investigate the effects of varying intensities and rest period lengths, while controlling for volume load, on vertical jump (VJ) performance. Thirteen men, aged 21 6 3 years with an average relative full squat of 1.7 6 2 times their body weight, were recruited for this study. Participants were assigned to 3 different experimen-tal sessions that required them to perform the back squat at 56% (low intensity), 70% (moderate intensity), and 93% (high intensity) of their 1 repetition maximums. Vertical jump height and power were recorded at 0, 2, 4, 8, and 12 minutes after squat. There was a significant condition by time interaction for VJ height and power, in which both variables did not change in the low-intensity condition, whereas decreasing immediately after squat for both the moderate-and high-intensity conditions. In the moderate-and high-intensity conditions, VJ height and power increased and peaked at minute 4 and returned to base-line by minutes 8 and 12. These results indicate that when controlling for total work, jump performance and power are enhanced similarly by moderate and high squat intensities. However, high-intensity workloads may prolong the duration of PAP. Therefore, athletes may use moderate-and high-inten-sity loads during warm-ups to improve jump performance and power.
Background Beta-hydoxy-beta-methyl butyrate (HMB) when given over a two-week period of time (loading phase) has been demonstrated to decrease skeletal muscle damage, and improve recovery. However, few studies have investigated its acute effects on muscle damage and recovery. Therefore the purpose of this investigation was to determine the effects of short term free acid HMB (HMB-FA) supplementation on serum indices of muscle damage and perceived recovery following a high volume, muscle damaging training session. Methods
Results There were no differences in total calories, protein, carbohydrate, or fat consumed between groups. There were time, and group x time effects (p<0.05) for total strength, which increased by a greater percentage in the HMB (430.4 ±2 2.5 to 507.5 ±2 1.7 kg; +1 8.3 %) than the placebo group (422.2 ± 24.9 to 447.5 ± 22.5 kg; + 6.6 %). There were time, and group x time effects (p<0.05) for Wingate peak power, which increased to a greater extent in the HMB (876.6 ± 46.0 to 1035.5 ± 55.7 watts; + 21.9 %) than the placebo group (882.9± 50.8 to 986.3 ± 22.5 kg; + 16.2 %) p<0.05). Finally there were time, and group x time effects (p<0.05) for muscle thickness, which increased to a greater extent in the HMB (50.7 ± 1.6 to 57.8 ± 1.7 cm; + 14.5 %) than the placebo group (49.6± 1.7 to 52.0 ± 1.9 cm; + 4.7 %) (p<0.05).
- Aug 2012
GROUPS OF AMINO ACIDS, AS WELL AS INDIVIDUAL AMINO ACIDS, HAVE BEEN STUDIED FOR THEIR ROLES IN PROTEIN BALANCE, HORMONE SECRETION, IMMUNE FUNCTION, OR CAPACITY TO BE CONVERTED TO VARIOUS ANABOLIC OR ANTICATABOLIC METABOLITES. SPECIFIC AMINO ACIDS WITH EXTENSIVE ANALYSIS INCLUDE THE ESSENTIAL AMINO ACIDS, BRANCHED CHAIN AMINO ACIDS, ARGININE, TAURINE, GLUTAMINE, β-ALANINE, AND THE LEUCINE METABOLITE, β-HYDROXY-β-METHYLBUTYRATE. THE PURPOSE OF THIS ARTICLE IS TO ANALYZE THE POSSIBLE ROLES AND PRACTICAL APPLICATIONS OF THESE AMINO ACIDS IN THE REGULATION OF BODY COMPOSITION AND PERFORMANCE IN ANAEROBIC AND AEROBIC SPORTS.
There is no clear agreement regarding the ideal combination of factors needed to optimize Post Activation Potentiation (PAP) following a conditioning activity. Therefore a meta analysis was conducted to evaluate the effects of training status, volume, rest period length, conditioning activity, and gender on power augmentation due to PAP. A total of 141 Effect Sizes (ES) for muscular power were obtained from a total of 32 primary studies, which met our criteria of investigating the effects of a heavy pre conditioning activity on power in randomized human trials. The mean overall ES for muscle power was 0.38 following a conditioning activity (p <0.05). Significant differences were found between moderate intensity (60-84 %) 1.06 and heavy intensity (>85 %) 0.31 (P < 0.05). There were overall significant differences found between single sets 0.24 and multiple sets 0.66 (P < 0.05). Rest periods of 7-10 minutes (0.7) following a conditioning activity resulted in greater ES than 3-7 minutes (0.54), which was greater than rest periods of >10 minutes (0.02) (P < 0.05). Significant differences were found between untrained 0.14 and athletes 0.81, as well as between trained 0.29 and athletes. The primary findings of this study were that a conditioning activity augmented power output, and these effects increased with training experience, but did not differ significantly between genders. Moreover, potentiation was optimal following multiple (vs. single) sets, performed at moderate intensities, and using moderate rest periods lengths (7-10 minutes).
- May 2012
Skeletal muscle hypertrophy and increases in muscular function have been observed following low intensity/load exercise with blood flow restriction (BFR). The mechanisms behind these effects are largely unknown, but have been hypothesized to include a metabolic accumulation induced increase in muscle activation, elevations in growth hormone, and improvements in muscle protein balance. However, many of the aforementioned mechanisms are not present with BFR in the absence of exercise. In these situations, signaling through the β2 adrenoceptor has been hypothesized to possibly contribute to the positive muscle adaptions, possibly in concert with muscle cell swelling. Signaling through the β2 adrenoceptor has been shown to stimulate both muscle protein synthesis and an inhibition of protein degradation through increasing cyclic adenosine monophosphate (cAMP) or signaling via the Gβγ subunit, especially in situations where the basal rates of protein synthesis are already reduced. Every study that has investigated the catecholamine response to BFR in the absence of exercise or in combination with exercise has shown a significant increase above resting conditions. However, from the available evidence, it is unlikely that the norepinephrine response from BFR, particularly with exercise, is playing a prominent role with muscle adaptation in skeletal muscle that is not immobilized by a cast or joint injury.