Article

A single versus multiple bouts of moderate-intensity exercise for fat metabolism

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Abstract

This study compared the fat metabolism between 'a single bout of 30-min exercise' and 'three bouts of 10-min exercise' of the same intensity (60% maximal oxygen uptake) and total exercise duration (30 min). Nine healthy men participated in three trials: (1) a single 30-min bout of exercise (Single), (2) three 10-min bouts of exercise, separated by a 10-min rest (Repeated) and (3) rest (Rest). Each exercise was performed with a cycle ergometer at 60% of maximal oxygen uptake, followed by 180-min rest. Blood lactate concentration increased significantly after exercise in the Single and Repeated trials (P < 0.05), but the Single trial showed a significantly higher value during the recovery period (P < 0.05). No significant difference was observed in the responses of plasma glycerol concentration. The Repeated trial produced a smaller increase in the ratings of perceived exertion during the exercise (P < 0.01). During the exercise, no significant difference was observed in respiratory exchange ratio (RER) between the Single and Repeated trials. However, the RER values during the recovery period were significantly lower in the Repeated trial than in the Single and Rest trials (P < 0.05), indicating higher relative contribution of fat oxidation in the Repeated trial (P < 0.05). These results suggest that the repetition of 10-min of moderate exercise can contribute to greater exercise-induced fat oxidation compared with a single 30-min bout of continuous exercise.

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... running at 70% of VO 2peak ). These findings imply that comparable metabolic responses can be either way obtained as long as total exertion time and intensity remain the same (Goto et al. 2011). ...
... In contrast, a variety of investigations report on greater exercise-induced fat mobilization following several (shorter) bouts of exercise with breaks in between, compared with a single (longer) bout (Goto et al. 2011). More specifically, Goto et al. (2007) reported on greater increases in FFAs, glycerol and ketone body concentrations, but also in fat oxidation during the 60 min following two 30 min bouts of exercise with 20 min rests in between, compared with a single 60 min bout. ...
... All sessions were conducted on a cycle ergometer at 90% of VO 2peak . In elaboration out of these 27 findings, Goto et al. (2011) found that three 10 min bouts of exercise with 10 min breaks in between produced a greater exercise-induced fat oxidation (∼15% postprandial), compared to a single 30 min bout. All sessions were conducted on a cycle ergometer at 60% of VO 2peak . ...
Thesis
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Introduction: Carbohydrate (CHO) and fat are the main substrates to fuel prolonged endurance exercise, each having its oxidation patterns regulated by several factors such as intensity, duration and mode of the activity, dietary intake pattern, muscle glycogen concentrations, gender and training status. Exercising at intensities where fat oxidation rates are high has been shown to induce metabolic benefits in recreational and health-oriented sportsmen. The exercise intensity (Fatpeak) eliciting peak fat oxidation rates is therefore of particular interest when aiming to prescribe exercise for the purpose of fat oxidation and related metabolic effects. Although running and walking are feasible and popular among the target population, no reliable protocols are available to assess Fatpeak as well as its actual velocity (VPFO) during treadmill ergometry. Moreover, to date, it remains unclear how pre-exercise CHO availability modulates the oxidative regulation of substrates when exercise is conducted at the intensity where the individual anaerobic threshold (IAT) is located (VIAT). That is, a metabolic marker representing the upper border where constant load endurance exercise can be sustained, being commonly used to guide athletic training or in performance diagnostics. The research objectives of the current thesis were therefore, 1) to assess the reliability and day-to-day variability of VPFO and Fatpeak during treadmill ergometry running; 2) to assess the impact of high CHO (HC) vs. low CHO (LC) diets (where on the LC day a combination of low CHO diet and a glycogen depleting exercise was implemented) on the oxidative regulation of CHOs and fat while exercise is conducted at VIAT. Methods: Research objective 1: Sixteen recreational athletes (f=7, m=9; 25 ± 3 y; 1.76 ± 0.09 m; 68.3 ± 13.7 kg; 23.1 ± 2.9 kg/m²) performed 2 different running protocols on 3 different days with standardized nutrition the day before testing. At day 1, peak oxygen uptake (VO2peak) and the velocities at the aerobic threshold (VLT) and respiratory exchange ratio (RER) of 1.00 (VRER) were assessed. At days 2 and 3, subjects ran an identical submaximal incremental test (Fat-peak test) composed of a 10 min warm-up (70% VLT) followed by 5 stages of 6 min with equal increments (stage 1 = VLT, stage 5 = VRER). Breath-by-breath gas exchange data was measured continuously and used to determine fat oxidation rates. A third order polynomial function was used to identify VPFO and subsequently Fatpeak. The reproducibility and variability of variables was verified with an intraclass correlation coefficient (ICC), Pearson’s correlation coefficient, coefficient of variation (CV) and the mean differences (bias) ± 95% limits of agreement (LoA). Research objective 2: Sixteen recreational runners (m=8, f=8; 28 ± 3 y; 1.76 ± 0.09 m; 72 ± 13 kg; 23 ± 2 kg/m²) performed 3 different running protocols, each allocated on a different day. At day 1, a maximal stepwise incremental test was implemented to assess the IAT and VIAT. During days 2 and 3, participants ran a constant-pace bout (30 min) at VIAT that was combined with randomly assigned HC (7g/kg/d) or LC (3g/kg/d) diets for the 24 h before testing. Breath-by-breath gas exchange data was measured continuously and used to determine substrate oxidation. Dietary data and differences in substrate oxidation were analyzed with a paired t-test. A two-way ANOVA tested the diet X gender interaction (α = 0.05). Results: Research objective 1: ICC, Pearson’s correlation and CV for VPFO and Fatpeak were 0.98, 0.97, 5.0%; and 0.90, 0.81, 7.0%, respectively. Bias ± 95% LoA was -0.3 ± 0.9 km/h for VPFO and -2 ± 8% of VO2peak for Fatpeak. Research objective 2: Overall, the IAT and VIAT were 2.74 ± 0.39 mmol/l and 11.1 ± 1.4 km/h, respectively. CHO oxidation was 3.45 ± 0.08 and 2.90 ± 0.07 g/min during HC and LC bouts respectively (P < 0.05). Likewise, fat oxidation was 0.13 ± 0.03 and 0.36 ± 0.03 g/min (P < 0.05). Females had 14% (P < 0.05) and 12% (P > 0.05) greater fat oxidation compared to males during HC and LC bouts, respectively. Conclusions: Research objective 1: In summary, relative and absolute reliability indicators for VPFO and Fatpeak were found to be excellent. The observed LoA may now serve as a basis for future training prescriptions, although fat oxidation rates at prolonged exercise bouts at this intensity still need to be investigated. Research objective 2: Twenty-four hours of high CHO consumption results in concurrent higher CHO oxidation rates and overall utilization, whereas maintaining a low systemic CHO availability significantly increases the contribution of fat to the overall energy metabolism. The observed gender differences underline the necessity of individualized dietary planning before exerting at intensities associated with performance exercise. Ultimately, future research should establish how these findings can be extrapolated to training and competitive situations and with that provide trainers and nutritionists with improved data to derive training prescriptions.
... Numerous studies have examined the beneficial effects of aerobic exercise on measures of obesity and cardiometabolic risk factors (Katzmarzyk et al., 2003;Johnson et al., 2007;Lakka & Laaksonen, 2007). Although both carbohydrates and fat are utilized as energy substrates during aerobic exercise, repeated bouts of exercise separated by periods of rest elicit greater exercise-induced fat mobilization than a single bout of exercise (Goto et al., 2007(Goto et al., , 2011. Additionally, adipose tissue lipolysis (increase in free fatty acids (FFA) and glycerol) during aerobic exercise of moderate intensity is enhanced when exercise is performed repeatedly with the same intensity and duration (Stich et al., 2000;Goto et al., 2007). ...
... However, whether the combination of coffee ingestion and repeated bouts of exercise effectively promotes fat metabolism has not yet been determined. In previous studies, moderate-to vigorous-intensity exercise (50-75% maximal oxygen uptake [ _ VO 2 max]) has been used to measure the amount of fat oxidation during multiple bouts of exercise (Stich et al., 2000;Ronsen et al., 2001;Goto et al., 2007Goto et al., , 2011. The Guidelines for Exercise Testing and Prescription from the American College of Sports Medicine recommend low-impact aerobic activities such as brisk walking, water aerobics, recreational cycling and leisurely dancing for all adults (Pescatello et al., 2013). ...
... Thus, multiple bouts of exercise might induce greater fat oxidation than does a traditional, single bout of exercise. Actually, Goto et al. (2011) have shown that the average %fat contribution to total energy expenditure throughout the 180-min recovery period was approximately 15% higher in repeated bouts than in a single bout of exercise. In addition, Stich et al. (2000) suggested that greater fat oxidation during repeated exercise bouts is related to the increase in FFA response caused by higher epinephrine (lipolytic hormone) and lower insulin responses (antilipolytic hormone) during repeated exercise. ...
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We investigated the effect of the combination of coffee ingestion and repeated bouts of low-intensity exercise on fat oxidation. Subjects were seven young, healthy male adults. They performed four trials: a single 30-min bout of exercise following ingestion of plain hot water (WS) or coffee (CS); a trial with three 10-min bouts of exercise separated by 10-min periods of rest following ingestion of plain hot water (WR) or coffee (CR). The coffee contained 5 mg kg(-1) of caffeine. All trials were performed on a cycle ergometer at 40% maximal oxygen uptake for each subject an hour after beverage ingestion. Oxygen uptake in the CS and CR trials was higher compared with the WS and WR trials at 90 min after exercise (P<0·05). Respiratory exchange ratio (RER) in the CS and CR trials was decreased during the whole recovery period compared with baseline (P<0·05), whereas no significant decreases were observed in either the WS or WR trials. Moreover, RER was significantly lower at 30 min after exercise in the CR trial than in either the WS or WR trials (P<0·05 each). Similarly, it is notable that fat oxidation rate in the CR trial was significantly higher at 30 min after exercise compared to that in the WS and WR trials (P<0·05). These results suggest that the combination of coffee intake and repeated bouts of low-intensity exercise enhances fat oxidation in the period after exercise. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.
... running at 70% of VO 2peak ). These findings imply that comparable metabolic responses can be either way obtained as long as total exertion time and intensity remain the same ( Goto et al. 2011). ...
... In contrast, a variety of investigations report on greater exercise-induced fat mobilization following several (shorter) bouts of exercise with breaks in between, compared with a single (longer) bout ( Goto et al. 2011). More specifically, Goto et al. (2007) reported on greater increases in FFAs, glycerol and ketone body concentrations, but also in fat oxidation during the 60 min following two 30 min bouts of exercise with 20 min rests in between, compared with a single 60 min bout. ...
... All sessions were conducted on a cycle ergometer at 90% of VO 2peak . In elaboration out of these 27 findings, Goto et al. (2011) found that three 10 min bouts of exercise with 10 min breaks in between produced a greater exercise-induced fat oxidation (∼15% postprandial), compared to a single 30 min bout. All sessions were conducted on a cycle ergometer at 60% of VO 2peak . ...
... In addition to this benefit, R-EX improves body composition (e.g., reduced body weight and body fat mass), cardiovascular function (e.g., reduced blood pressure), and exercise tolerance (e.g., increased peak oxygen consumption [VO 2 peak ]) similarly to S-EX in various populations, including older individuals and patients with chronic disease (Jakicic et al., 1999;Murphy & Hardman, 1998;Schmidt, Biwer, & Kalscheuer, 2001). Furthermore, previous laboratory-based studies reported that aerobic exercise-induced increases in systemic fatty acid metabolic parameters (e.g., increased blood free fatty acid levels and whole-body fatty acid oxidation) were greater following R-EX than following S-EX (Goto, Ishii, Mizuno, & Takamatsu, 2007;Goto, Tanaka, Ishii, Uchida, & Takamatsu, 2011;Kurobe, Nakao, Nishiwaki, & Matsumoto, 2017;Stich et al., 2000); therefore, these acute responses support the beneficial long-term effects of R-EX on many health parameters. Taking these findings into consideration, R-EX is an effective exercise protocol for improving public health. ...
... Given the results of the present study, we hypothesized that a 20-min rest interval during R-EX might result in wash-out of postexercise IC changes following the first bout; therefore, a rest interval shorter than 20 min may mitigate the wash-out effect. Additionally, several previous studies employed three 10-min bouts (which are separated by two rest intervals for 10 min) for the R-EX protocol (Goto et al., 2011;Jones et al., 2009;Kurobe et al., 2017). Further studies are needed to determine the effective protocols of R-EX on postexercise IC changes. ...
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We previously demonstrated that duration of aerobic exercise plays an important role in improving cognitive inhibitory control (IC). Repeated bouts of aerobic exercise (R‐EX), which are performed with a rest interval, is a useful strategy in improving physical health parameters in similar manners to a single bout of aerobic exercise (S‐EX). However, whether R‐EX would be effective in improving IC remains unknown. This study compared the effect of R‐EX versus S‐EX of moderate‐intensity exercise on postexercise IC. Twenty healthy, young males performed both R‐EX and S‐EX in a crossover design. R‐EX consisted of two 20‐min moderate‐intensity bouts (60% of peak oxygen consumption) for 20 min, which were separated by a 20‐min rest interval. S‐EX consisted of a once‐off 40‐min moderate‐intensity bout without rest interval. To evaluate IC, the color‐word Stroop task was administered before exercise, immediately after exercise, and every 10 min during the 30‐min postexercise recovery period. The reverse‐Stroop interference score, which is a parameter of IC, significantly decreased immediately after both R‐EX and S‐EX compared with that before each exercise (both Ps < 0.05). The degree of changes in IC following exercise did not differ between the two protocols. By contrast, the results of the present study showed that R‐EX may have more beneficial effects on cardiac and perceptual responses than S‐EX. Therefore, the present study determined that R‐EX changes postexercise IC similar to S‐EX. We suggest that R‐EX can be used as safe and effective exercise protocol to improve cognitive function in various populations. Aerobic exercise improves postexercise cognitive function. Effective aerobic exercise protocols for improving cognitive function are poorly understood. A repeated bout protocol of aerobic exercise can be used as safe and effective exercise protocol to improve cognitive functioin.
... The physiological effects of continuous endurance exercise on ANP release and plasma free fatty acid (FFA) concentrations have been well described [1,3]. The further enhancement of fat metabolism using high-intensity intermittent exercise protocols has been the focus of more recent investigations [10][11][12][13]. High intensity intermittent exercise provides more potent metabolic stimuli, leading to increased lactate and catecholamine levels. ...
... Differences in these hormones between high-intensity intermittent exercise protocols compared to less intense protocols have not yet been analyzed; studies investigating intermittent bouts of exercise results were in contrast to moderate continuous exercise of the same duration. Different scores relative to the contribution of fat oxidation for repeated trials (77.6% ± 2.7%) versus single trials (62.1% ± 5.7%) were computed in the study of Goto et al. [11]. A test would require less than 10 subjects in each group, assuming a similar response to water immersion. ...
Article
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Background: Atrial natriuretic peptides (ANP) and Brain natriuretic peptides (BNP) stimulate fat cell plasma membrane receptors. They are potent lipolytic agents on isolated fat cells from subcutaneous adipose tissue. The physiological effects of continuous endurance exercise on ANP release and plasma free fatty acids (FFA) concentrations have been well described. The enhancement of fat metabolism using high intensity intermittent exercise protocols has been assessed in more recent investigations. The combined effects of endurance exercise and water immersion on ANP and FFA plasma concentration and the magnitude of excess post-exercise oxygen consumption (EPOC) might be further enhanced by choosing the most effective exercise protocol. Exercise modalities may play a significant role in the future prevention and treatment of obesity. Methods/design: The two testing trials will be performed according to a randomized and cross-over design. Twenty healthy sedentary pre-obese and obese class-1 men will be scrutinized with regard to their metabolic responses to continuous exercise in water and to high intensity endurance exercise in water. Both trials will be matched for energy expenditure. After preliminary testing, the tests will be conducted as repeated measurements. The two different exercise protocols will be compared. The aims of the study are to investigate (1) whether continuous endurance exercise or high intensity intermittent endurance exercise in water elicits both a higher release of ANP and BNP and a higher plasma concentration of glycerol and (2) to determine whether continuous endurance exercise in water or a high intensity intermittent endurance exercise in water would lead to a more pronounced short term (two hours) EPOC effect. Discussion: If our hypothesis would be confirmed, the most effective exercise protocol based on the combined effects of high intensity endurance exercise and water immersion on ANP and BNP release and glycerol plasma concentrations can be identified. Moreover, the magnitude of the EPOC effect can be augmented. Our study would provide a major contribution for creating optimized exercise modalities in the prevention and treatment of obesity. Trial registration: Current controlled trials, ISRCTN95488515.
... Research is still conflicted on whether aerobic or resistance exercise is more effective for augmenting EE. Higher intensity exercise has also been linked to higher rates of fat oxidation, measured by respiratory exchange ratio (RER) [6,11,12]. ...
... Within 25 min afterward, RER was significantly lower than AEE (p < 0.001), demonstrating higher fat utilization, which was maintained up to 60 min post. Similar to the current study, previous studies have reported a significantly lower RER post exercise with repeated bouts of moderate intensity cycling, compared to a single bout [12] and a lower RER with a lower vs. higher intensity cycle bout (50% and 70% VO 2max ) through 3 h post exercise, indicating increased fat utilization [11]. Previous data demonstrates differing exercise intensity can augment post-exercise REE and fat oxidation, but intervals do not produce differences compared to continuous exercise if total EE, duration, and intensity between the two remain the same throughout the exercise bout. ...
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The purpose of this study was to examine the effect of exercise modality and pre-exercise carbohydrate (CHO) or protein (PRO) ingestion on post-exercise resting energy expenditure (REE) and respiratory exchange ratio (RER) in women. Twenty recreationally active women (mean ± SD; age 24.6 ± 3.9 years; height 164.4 ± 6.6 cm; weight 62.7 ± 6.6 kg) participated in this randomized, crossover, double-blind study. Each participant completed six exercise sessions, consisting of three exercise modalities: aerobic endurance exercise (AEE), high-intensity interval running (HIIT), and high-intensity resistance training (HIRT); and two acute nutritional interventions: CHO and PRO. Salivary samples were collected before each exercise session to determine estradiol-β-17 and before and after to quantify cortisol. Post-exercise REE and RER were analyzed via indirect calorimetry at the following: baseline, immediately post (IP), 30 minutes (30 min) post, and 60 minutes (60 min) post exercise. A mixed effects linear regression model, controlling for estradiol, was used to compare mean longitudinal changes in REE and RER. On average, HIIT produced a greater REE than AEE and HIRT (p < 0.001) post exercise. Effects of AEE and HIRT were not significantly different for post-exercise REE (p = 0.1331). On average, HIIT produced lower RER compared to either AEE or HIRT after 30 min (p < 0.001 and p = 0.0169, respectively) and compared to AEE after 60 min (p = 0.0020). On average, pre-exercise PRO ingestion increased post-exercise REE (p = 0.0076) and decreased post-exercise RER (p < 0.0001) compared to pre-exercise CHO ingestion. HIIT resulted in the largest increase in REE and largest reduction in RER.
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OBJECTIVES The purpose of this study was to compare excess post-exercise oxygen consumption (EPOC) and energy expenditure during (30min) and following (60min) exercise for a 30min continuous bouts of treadmill exercise at 60%VO2R compared to three 10min bouts of intermittent treadmill exercise at the same intensity. METHODS Seventeen fit college-aged males (n=7) and females (n=10) volunteered to participate. Treadmill exercise bouts were separated by 48h and performed in a randomized counter-balanced order. The 30min continuous bout of exercise included a 60min recovery and each of the three 10min bouts included 20min of recovery. RESULTS During the rest and exercise, oxygen uptake (VO2) and exercise expenditure (EE) were not significant difference between the intermittent and continuous trails. But during the recovery, VO2 and EE were significantly higher intermittent than continuous trails in male and female (p
... Rights reserved. Table 1 Schlierf et al. [62] Bahr et al. [35] Lee et al. [53] Ezell et al. [43] a Ezell et al. [43] b Ezell et al. [43] c Ronsen et al. [61] Marion-Latard et al. [54] Petridou et al. [59] Bergfors et al. [37] Enevoldsen et al. [14] Burns et al. [15] Clegg et al. [40] McClean et al. [56] Tobin et al. [24] Højbjerre et al. [ King et al. [51] Morris et al. [57] Vendelbo et al. [67] Balaguera-Cortes et al. [36] Charlot et al. [39] Goto et al. [46] Farah & Gill [44] Gonzalez et al. [ ...
Article
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Background Elevated glucose and insulin levels are major risk factors in the development of cardiometabolic disease. Aerobic exercise is widely recommended to improve glycaemic control, yet its acute effect on glycaemia and glucoregulatory hormones has not been systematically reviewed and analysed in healthy adults. Objective To determine the effect of a single bout of continuous aerobic exercise on circulating glucose, insulin, and glucagon concentrations in healthy adults. Methods CENTRAL, CINAHL, Embase, Global Health, HMIC, Medline, PubMed, PsycINFO, ScienceDirect, Scopus and Web of Science databases were searched from inception to May 2020. Papers were included if they reported a randomised, crossover study measuring glucose and/or insulin and/or glucagon concentrations before and immediately after a single bout of continuous aerobic exercise (≥ 30 min) compared to a time-matched, resting control arm in healthy adults. The risk of bias and quality of evidence were assessed using the Cochrane Risk of Bias Tool and GRADE approach, respectively. Random-effects meta-analyses were performed for glucose, insulin, and glucagon. Sub-group meta-analyses and meta-regression were performed for categorical (metabolic state [postprandial or fasted], exercise mode [cycle ergometer or treadmill]) and continuous (age, body mass index, % males, maximal aerobic capacity, exercise duration, exercise intensity) covariates, respectively. Results 42 papers (51 studies) were considered eligible: glucose (45 studies, 391 participants), insulin (38 studies, 377 participants) and glucagon (5 studies, 47 participants). Acute aerobic exercise had no significant effect on glucose concentrations (mean difference: − 0.05 mmol/L; 95% CI, − 0.22 to 0.13 mmol/L; P = 0.589; I²: 91.08%, large heterogeneity; moderate-quality evidence). Acute aerobic exercise significantly decreased insulin concentrations (mean difference: − 18.07 pmol/L; 95% CI, − 30.47 to − 5.66 pmol/L; P = 0.004; I²: 95.39%, large heterogeneity; moderate-quality evidence) and significantly increased glucagon concentrations (mean difference: 24.60 ng/L; 95% CI, 16.25 to 32.95 ng/L; P < 0.001; I²: 79.36%, large heterogeneity; moderate-quality evidence). Sub-group meta-analyses identified that metabolic state modified glucose and insulin responses, in which aerobic exercise significantly decreased glucose (mean difference: − 0.27 mmol/L; 95% CI, − 0.55 to − 0.00 mmol/L; P = 0.049; I²: 89.72%, large heterogeneity) and insulin (mean difference: − 42.63 pmol/L; 95% CI, − 66.18 to − 19.09 pmol/L; P < 0.001; I²: 81.29%, large heterogeneity) concentrations in the postprandial but not fasted state. Meta-regression revealed that the glucose concentrations were also moderated by exercise duration and maximal aerobic capacity. Conclusions Acute aerobic exercise performed in the postprandial state decreases glucose and insulin concentrations in healthy adults. Acute aerobic exercise also increases glucagon concentrations irrespective of metabolic state. Therefore, aerobic exercise undertaken in the postprandial state is an effective strategy to improve acute glycaemic control in healthy adults, supporting the role of aerobic exercise in reducing cardiometabolic disease incidence. PROSPERO registration number CRD42020191345.
... Murphy et al. 19 reported that total duration of exercise similarly benefits overall health, blood pressure, and TG reactions, as do repeated and continuous exercises of the same duration. Furthermore, Goto et al. 37 reported that dividing the accumulated exercise of total 30 minutes into 10-minute durations results in a similar 30-minute exercise. ...
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Purpose: The purpose of this study was to compare the excess post-exercise oxygen consumption (EPOC) between different types of exercises in women with normal weight obesity (NWO). Methods: Nine university students with NWO having body mass index <25 kg/m2 and body fat percentage >30% participated in the study. First, continuous exercise (CEx) on an ergometer for 30 minutes at 60% of maximal oxygen consumption (VO2max) and interval exercise (IEx) at 80% VO2max for 2 minutes were performed. This was followed by exercise performed at 40% VO2max for 1 minute and at 80% VO2max for 3 minutes, performed 6 times repeatedly for a total of 26 minutes. The accumulation of short duration exercise (AEx) was performed for 3-bouts of 10 minutes each at 60% VO2max. Results: The major findings were as follows: energy consumption during the exercises showed no significant difference between CEx, IEx, and AEx; EPOC was higher in IEx and AEx as compared to CEx for all dependent variables (e.g. total oxygen consumption, total calorie, summation of heart rate, and EPOC duration); and the lipid profile showed no significant difference. Conclusion: Our study confirmed that when homogenizing the energy expenditure for various exercises in NWO individuals, EPOC was higher in IEx and AEx than in CEx. Therefore, IEx and AEx can be considered as effective exercise methods for increasing energy expenditure in NWO females.
... Goto et al. [13] demonstrated that two steady-state sessions of 30 minutes to 60% VO2max separated by 20 minutes of rest resulted in an increase in lipid expenditure compared to a single 60-minute steady state session performed at the same intensity. Goto et al. [14] confirmed the previous conclusions with three 10-minute aerobic efforts separated by 10 minutes of rest. These were able to lead to increased fat oxidation compared to 30 minutes of continued exercise. ...
... Although a previous study has suggested that the repetition of moderate exercise can contribute to greater exercise-induced lipid oxidation, a better lipid profile after the halftime period was not observed in this study. This may be due to the duration of exercise may be not long enough to shift from carbohydrate to lipid oxidation (6). ...
Article
Yanaoka, T, Yamagami, J, Kidokoro, T, Kashiwabara, K, and Miyashita, M. Halftime rewarm-up with intermittent exercise improves the subsequent exercise performance of soccer referees. J Strength Cond Res 32(1): 211-216, 2018-This study investigated the effect of halftime rewarm-up (RW) with intermittent exercise on the subsequent exercise performance of soccer referees, determined by the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1). Using a randomized cross-over design, 10 male referees were required to complete 2 trials. The trials consisted of the Loughborough Intermittent Shuttle Test, halftime, and Yo-Yo IR1 periods. During halftime, participants either rested on a chair (Control) or performed a halftime RW exercise for 15 minutes. The halftime RW protocol comprised 2.15 minutes of seated rest, followed by 2.15 minutes of running at 70% of the maximum heart rate (HRmax)-this cycle of recovery and running was repeated for a total of 13 minutes. The halftime RW protocol started at 1 minute after the commencement of the halftime period and concluded 1 minute before its end. The Yo-Yo IR1 performance, blood glucose, free fatty acids (FFAs), triglycerides (TGs), creatine kinase (CK), and lactate concentrations, the rating of perceived exertion, mean HR, and HRmax were analyzed. The Yo-Yo IR1 performance was higher in the halftime RW trial than in the control trial (3,095 ± 326 vs. 2,904 ± 421 m, P ≤ 0.05). The mean HR and HRmax, blood glucose, FFA, TG, CK, and lactate concentrations did not differ between the trials. The rating of perceived exertion during the halftime RW, but not after the Yo-Yo IR1 period, was higher than that in the control trial. In conclusion, this study showed that halftime RW with intermittent exercise improves the subsequent exercise performance.
... Furthermore, splitting the daily exercise into several small bouts has been demonstrated to be more effective, and potentially more time-efficient for glycemic control than a single longer bout (Eriksen et al. 2007;Francois et al. 2014). Indeed, a second bout of exercise shortly after the first one appears to decrease blood glucose more than a single-continuous isoenergetic bout in healthy adults (Goto et al. 2011). However, such effect of repeated bouts of exercise has not yet been tested in diabetic patients. ...
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Purpose: Postprandial hyperglycemia and glycemic oscillations have been associated with increased oxidative stress. We sought to investigate the effect of two walking exercise protocols performed during lunchtime on glycemic control and oxidative stress in type 2 diabetic (T2D) patients. Methods: Nine T2D patients participated in three randomized crossover trials; a control trial (Con), with participants having a standard lunch followed by their normal daily activities and two exercise trials (ContEx and Splitex). In ContEx, subjects performed 40 min of brisk walking 40 min after lunch, whereas in SplitEx the walking exercise was divided in two 20-min isoenergetic bouts, before and 40 min after meal. 24-h glycemic control was monitored by continuous glucose monitoring. 24-h urinary levels of 8-iso PGF2ɑ were measured as a marker of oxidative stress. Results: SplitEx resulted in less time spent in moderate hyperglycemia after lunch vs ContEx (42.4 ± 38.7 % vs 68.2 ± 32.7 %, P = 0.04). ContEx reduced hyperglycemic time after breakfast consumed the morning after the exercise session (58.3 ± 29.6 Con vs 40.2 ± 33.4 % ContEx, P = 0.02). Compared with Con, 24-h urinary isoprostanes were decreased both in ContEx (-68 %, P = 0.02) and SplitEx (-63 %, P = 0.04). Conclusions: Splitting an exercise session into two bouts, pre- and post-lunch, affects mainly the glycemic response to lunch, while a single-continuous isoenergetic session exerts its effect later in the 24-h period. Both exercise modalities effectively attenuate systemic oxidative stress with similar overall benefits.
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This review provides information about the effects of high intensity intermittent training (HIIT) on variables related to the metabolic syndrome (MS). After the diagnoses criteria contextualization, results from exercise interventions on MS are presented, as well as the possibility of achieving benefits with HIIT. Eleven studies that assessed the acute effects and 16 that measured the chronic effects of exercise were recovered. Studies showed improvements in body composition (including visceral fat), cardiovascular variables (especially aerobic power) and metabolic components (mainly related to glycemia). When comparing different types of training, intermittent and continuous, there are favorable indications for the HIIT in most of the MS components. In conclusion, from this study, it appears that HIIT can be relevant for the prevention and treatment of the MS.
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To compare the acute effects of low-volume intermittent and higher-volume continuous exercise on arterial stiffness, 20 healthy men (22.4 ± 0.4 years) were randomized to non-exercise control (CON), high-volume Continuous Exercise (CE), lower-volume Intermittent exercise of Long bouts with Long interval (ILL), of Long bouts with Short interval (ILS), and of Short bouts with Short interval trial (ISS). Exercise intensity was 35% heart rate reserve. Arterial stiffness in Cardio-ankle vascular index (CAVI) was measured at baseline (BL), immediately (0 min) and 40 min after exercise. CAVI changes from BL in the same trial (⊿CAVI) were used for analysis. There was no significant ⊿CAVI change in CON. ⊿CAVI decreased significantly at 0 min in all exercise trials, and reverted to baseline at 40 min only in CE and ILL. At 40 min, ⊿CAVI in ILS and ISS remained significantly lower than that of CON and CE. When ILS and ISS were compared with CON at 40 min, only ⊿CAVI in ISS remained significantly lower than that of CON. Despite low volume, the effect of intermittent exercise on arterial stiffness could be either equal or superior to that of higher-volume continuous exercise.
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To evaluate the "threshold" duration of exercise required to produce training effects, 18 healthy men aged 51 +/- 6 years completing 30 minutes of exercise training/day were compared with 18 men aged 52 +/- 6 years completing three 10-minute bouts of exercise/day, each separated by at least 4 hours. Exercise training intensity was moderate (65 to 75% of peak treadmill heart rate). During the 8-week study period VO2 max increased significantly in both groups from 33.3 +/- 3.2 to 37.9 +/- 3.5 ml/kg/min in men performing long exercise bouts and from 32.1 +/- 4.6 to 34.5 +/- 4.5 ml/kg/min in men performing short exercise bouts (p less than 0.05 within and between groups). Adherence to unsupervised exercise training performed at home and at work by men in long and short bouts was high; total duration of training completed was 96 and 93% of the prescribed amount and total number of sessions completed was 92 and 93% of that prescribed, respectively. In both groups exercise heart rate measured by a portable microprocessor was within or above the prescribed range for greater than 85% of the prescribed duration. Thus, multiple short bouts of moderate-intensity exercise training significantly increase peak oxygen uptake. For many individuals short bouts of exercise training may fit better into a busy schedule than a single long bout.
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The purpose of this study was to examine 1) the effect of two exercise intensities of equal caloric output on the magnitude (kcal) and duration of excess postexercise oxygen consumption (EPOC) and 2) the effect of exercise of equal intensity but varying duration on EPOC. Ten trained male triathletes performed three cycle ergometer exercises: high intensity-short duration (HS), low intensity-short duration (LS), and low intensity-long duration (LL). Baseline VO2 was measured for 1 h prior to each exercise condition. Postexercise VO2 was measured continuously until baseline VO2 was achieved. The duration of EPOC was similar for HS (33 +/- 10 min) and LL (28 +/- 14 min), and both were significantly longer (P less than 0.05) than the EPOC following LS (20 +/- 5 min). However, total net caloric expenditure was significantly more (P less than 0.05) for HS (29 +/- 8 kcal) than for either LS (14 +/- 6 kcal) or LL (12 +/- 7 kcal). The exercise conditions used in this study did not produce a prolonged EPOC. However, the exercise intensity was shown to affect both the magnitude and duration of EPOC, whereas the exercise duration affected only the duration of EPOC. Moreover, the duration of EPOC and the subsequent caloric expenditure were not necessarily related. Based on the resulting magnitude of the postexercise energy expenditure, it is possible that EPOC may be of some value for weight control over the long term.
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This study compared the effects of short and long bouts of brisk walking in sedentary women. Forty seven women aged 44.4 +/- 6.2 yr (mean +/- SD) were randomly assigned to either three 10-min walks per day (short bouts), one 30-min walk per day (long bouts) or no training (control). Brisk walking was done on 5 d x wk(-1), at 70 to 80% of maximal heart rate, typically at speeds between 1.6 and 1.8 m x s(-1) (3.5 and 4.0 mph), for 10 wk. Subjects agreed not to make changes to their diet. Twelve short-bout walkers, 12 long-bout walkers, and 10 controls completed the study. Relative to controls, VO2max (short-bout, +2.3 +/- 0.1 mL x kg(-1) x min(-1); long-bout, +2.4 +/- 0.1 mL x kg(-1) x min(-1); controls, -0.5 +/- 0.1 mL x kg(-1) x min[-1]) and the VO2 at a blood lactate concentration of 2 mmol x L(-1) increased in walkers (both P < 0.05), with no difference in response between walking groups. Neither heart rate during standard, submaximal exercise nor resting systolic blood pressure changed in a different way in walkers and controls. The sum of four skinfold thicknesses decreased in both walking groups (P < 0.05) but body mass (short-bout, -1.7 +/- 1.7 kg; long-bout, -0.9 +/- 2.0 kg; controls, +0.6 +/- 0.7 kg) and waist circumference decreased significantly only in short-bout walkers. Changes in anthropometric variables did not differ between short- and long-bout walkers. Thus short bouts of brisk walking resulted in similar improvements in fitness and were at least as effective in decreasing body fatness as long bouts of the same total duration.
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This study was designed to test different ways of meeting the new ACSM/CDC recommendations for physical activity stating that all Americans at least 2 years of age should obtain 30 minutes of moderate intensity activity on most days of the week. Thirty-two sedentary 18- to 55-year-old adults were randomly assigned to three groups of brisk walking/6 days per week: 30 continuous minutes, three 10-minute bouts, and 30 minutes in any combination of bouts as long as each bout was at least 5 minutes. Aerobic fitness, blood pressure, body composition, and physical activity were assessed at baseline, at end of program (16 weeks), and at follow-up (32 weeks). All groups significantly (P </= 0.05) improved their aerobic fitness and systolic blood pressure and increased their physical activity at the end of the program. At follow-up all groups maintained these changes, while additionally reducing their percentage body fat and diastolic blood pressure. These findings demonstrate that a walking prescription of 30 minutes per day on most days of the week with the choice to walk in as little as 5 minute bouts can improve cardiovascular health and body composition, as well as help sedentary people maintain those improvements over time. This is supported by all participants indicating that "making walking part of my lifestyle" was the most important factor in maintaining their walking habits.
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Enhancing participation in long-term exercise may translate into improved long-term weight loss in overweight adults. To compare the effects of intermittent with traditional continuous exercise on weight loss, adherence, and fitness, and to examine the effect of combining intermittent exercise with that using home exercise equipment. Randomized trial from September 1996 through September 1998. A total of 148 sedentary, overweight (mean [SD] body mass index, 32.8 [4.0] kg/m2) women (mean [SD] age, 36.7 [5.6] years) in a university-based weight control program. Eighteen-month behavioral weight control program with 3 groups: long-bout exercise (LB), multiple short-bout exercise (SB), or multiple short-bout exercise with home exercise equipment (SBEQ) using a treadmill. Body weight, body composition, cardiorespiratory fitness, and exercise adherence. Of 148 subjects, 115 (78%) completed the 18-month program. At 18 months, mean (SD) weight loss was significantly greater in subjects in the SBEQ group compared with subjects in the SB group (-7.4 [7.8] kg vs -3.7 [6.6] kg; P<.05). Mean (SD) weight loss for subjects in the LB group (-5.8 [7.1] kg) was not significantly different than for subjects in the SB or SBEQ groups. Subjects in the SBEQ group maintained a higher level of exercise than subjects in both the SB and LB groups (P<.05) at 13 to 18 months of treatment. All groups showed an increase in cardiorespiratory fitness from baseline to 18 months, with no difference between groups. Mean (SD) weight loss at 18 months was significantly greater in individuals exercising more than 200 min/wk throughout the intervention (-13.1 [8.0] kg) compared with individuals exercising 150 to 200 min/wk (-8.5 [5.8] kg) or less than 150 min/wk (-3.5 [6.5] kg) (P<.05). Compared with the LB group, subjects in the SB group did not experience improved long-term weight loss, exercise participation, or cardiorespiratory fitness. Access to home exercise equipment facilitated the maintenance of SB, which may improve long-term weight loss. A dose-response relationship exists between amount of exercise and long-term weight loss in overweight adult women.
Article
1. The relative roles of sympathetic nerve activity and circulating catecholamines for adipose tissue lipolysis during exercise are not known. 2. Seven paraplegic spinal cord injured (SCI, injury level T3-T5) and seven healthy control subjects were studied by microdialysis and (133)xenon washout in clavicular (Cl) and in umbilical (Um) (sympathetically decentralized in SCI) subcutaneous adipose tissue during 1 h of arm cycling exercise at approximately 60 % of the peak rate of oxygen uptake. 3. During exercise, adipose tissue blood flow (ATBF) and interstitial glycerol, lactate and noradrenaline concentrations increased significantly in both groups. Plasma catecholamine levels increased significantly less with exercise in SCI than in healthy subjects. The exercise-induced increase in interstitial glycerol concentration in subcutaneous adipose tissue was significantly lower in SCI compared with healthy subjects (SCI: 25 +/- 12 % (Cl), 36 +/- 20 % (Um); healthy: 60 +/- 17 % (Cl), 147 +/- 45 % (Um)) and the increase in ATBF was significantly lower (Cl) or similar (Um) in SCI compared with healthy subjects (SCI: 1.2 +/- 0.3 ml (100 g)(-1) min(-1) (Cl), 1.0 +/- 0.3 ml (100 g)(-1) min(-1) (Um); healthy: 2.8 +/- 0.7 ml (100 g)(-1) min(-1) (Cl), 0.6 +/- 0.3 ml (100 g)(-1) min(-1) (Um)). Accordingly, in both adipose tissues lipolysis increased less in SCI compared with healthy subjects, indicating that circulating catecholamines are important for the exercise-induced increase in subcutaneous adipose tissue lipolysis. In SCI subjects, the exercise-induced increase in subcutaneous adipose tissue lipolysis was not lower in decentralized than in sympathetically innervated adipose tissue. During exercise the interstitial noradrenaline and adrenaline concentrations were lower in SCI compared with healthy subjects (P < 0.05) and always lower than arterial plasma catecholamine concentrations (P < 0.05). 4. It is concluded that circulating catecholamines are important for the exercise-induced increase in subcutaneous adipose tissue lipolysis while sympathetic nerve activity is not.
Article
The purpose of this study was to test the hypothesis that carbohydrate (CHO) utilization in middle-aged trained men is increased during hard-intensity exercise and decreased during moderate-intensity exercise in comparison with age-matched sedentary men. We also investigated whether a relationship between CHO utilization and glucose disposal exists. Seven trained cyclists (Tr) and seven age-matched sedentary men (Sed) underwent an intravenous glucose tolerance test after an overnight fast (minimal model method) to determine their glucose disposal; they also performed two 1-h trials on a cycle ergometer below and above their individual ventilatory threshold (VT). Substrate oxidation was evaluated by indirect calorimetry. Hormonal responses were investigated during exercise. Insulin sensitivity (SI) and glucose effectiveness (Sg) were significantly higher in the Tr group than in the Sed group (P < 0.001, P < 0.03). CHO oxidation was significantly higher in the Tr group than in the Sed group when exercise was performed above VT, whereas CHO oxidation was higher in the Sed group when exercise was performed below VT (P < 0.05). Epinephrine (Epi) response during hard-intensity exercise was higher in the Tr group than in the Sed group (P < 0.01). SI was negatively correlated to CHO oxidation in the Tr group (r = -0.743, P < 0.05). Endurance training results in increased CHO utilization during hard-intensity exercise and reduced CHO oxidation during moderate-intensity exercise in middle-aged men. During hard-intensity exercise, the increased CHO utilization in middle-aged trained men is associated with a greater response in Epi and is inversely related with SI.
Article
Studies have shown metabolism to remain elevated for hours following resistance exercise, but none have gone beyond 16 h, nor have they followed a whole body, high intensity exercise protocol. To examine the duration of excess post-exercise oxygen consumption (EPOC) following a period of heavy resistance exercise, seven healthy men [mean (SD) age 22 (3) years, height 177 (8) cm, mass 83 (10) kg, percentage body fat 10.4 (4.2)%] engaged in a 31 min period of resistance exercise, consisting of four circuits of bench press, power cleans, and squats. Each set was performed using the subject's own predetermined ten-repetition maximum and continued until failure. Oxygen consumption ( ) measurements were obtained at consistent times (34 h pre-, 29 h pre-, 24 h pre-, 10 h pre-, 5 h pre-, immediately post-, 14 h post-, 19 h post-, 24 h post-, 38 h post-, 43 h post-, and 48 h post-exercise). Post-exercise measurements were compared to the baseline measurements made at the same time of day. The was significantly elevated ( P<0.05) above baseline values at immediately post, 14, 19, and 38 h post-exercise. Mean daily values for both post-exercise days were also significantly elevated above the mean value for the baseline day. These results suggest that EPOC duration following resistance exercise extends well beyond the previously reported duration of 16 h. The duration and magnitude of the EPOC observed in this study indicates the importance of future research to examine a possible role for high intensity resistance training in a weight management program for various populations.
Article
We compared the effects of one vs two daily bouts of walking on aerobic fitness and body composition in postmenopausal women. One hundred and thirty-four subjects were randomized into exercise groups or a control group and 130 completed the study. The subjects walked 5 d/week for 15 weeks at 65% of their maximal aerobic power expending 300 kcal (1255 kJ) in exercise in one (Group S1) or two daily sessions (Group S2). VO(2max) was measured in a direct maximal treadmill test. Body mass index (BMI) was calculated and the percentage of body fat (fat%) estimated using skinfold measurements. The net change in the VO(2max) was 2.5 mL min/kg (95% CI 1.5, 3.5) (8.7%) in Group S1 and 2.5 mL min/kg (95% CI 1.5, 3.5) (8.8%) in Group S2. The net change in body mass was -1.2 kg (95% CI-1.9, -0.5) in Group S1 and -1.1 kg (95% CI -1.8, -0.4) in Group S2. The net fat% change was -2.1% (95% CI-2.7, -1.4) in Group S1 and -1.7% (95% CI-2.3, -1.0) in Group S2. Exercise improved the maximal aerobic power and body composition equally when walking was performed in one or two daily bouts.
Article
A consensus meeting was held in Bangkok, 21–23 May 2002, where experts and young scientists in the field of physical activity, energy expenditure and body-weight regulation discussed the different aspects of physical activity in relation to the emerging problem of obesity worldwide. The following consensus statement was accepted unanimously. ‘The current physical activity guideline for adults of 30 minutes of moderate intensity activity daily, preferably all days of the week, is of importance for limiting health risks for a number of chronic diseases including coronary heart disease and diabetes. However for preventing weight gain or regain this guideline is likely to be insufficient for many individuals in the current environment. There is compelling evidence that prevention of weight regain in formerly obese individuals requires 60–90 minutes of moderate intensity activity or lesser amounts of vigorous intensity activity. Although definitive data are lacking, it seems likely that moderate intensity activity of approximately 45 to 60 minutes per day, or 1.7 PAL (Physical Activity Level) is required to prevent the transition to overweight or obesity. For children, even more activity time is recommended. A good approach for many individuals to obtain the recommended level of physical activity is to reduce sedentary behaviour by incorporating more incidental and leisure-time activity into the daily routine. Political action is imperative to effect physical and social environmental changes to enable and encourage physical activity. Settings in which these environmental changes can be implemented include the urban and transportation infrastructure, schools, and workplaces.’
Article
Guidelines state that accumulated physical activity is beneficial for health, but a minimum duration of 10 min per activity bout is recommended. Limited information regarding the effects of short (< 10 min) bouts of activity on health is available, and no studies of the effects of such short bouts of activity on postprandial lipemia have been conducted. The objective was to compare the effects of accumulating ten 3-min bouts of exercise with those of one 30-min bout of exercise on postprandial plasma triacylglycerol concentrations. Ten men aged 21-32 y completed three 2-d trials > or = 1 wk apart in a randomized repeated-measures design. On day 1, the subjects rested (no exercise) or ran at 70% of maximum oxygen uptake in either ten 3-min bouts (30 min rest between each) or one continuous 30-min bout. On day 2, the subjects rested and consumed test meals (0.69 g fat, 0.95 g carbohydrate, 0.31 g protein, and 46 kJ/kg body mass) for breakfast and lunch. Venous blood samples were obtained in the fasted state and for 7 h postprandially on day 2. Postprandial plasma triacylglycerol concentrations were lower throughout day 2 of both the accumulation exercise trial and the continuous exercise trial than during the control trial (main effect of trial: P < 0.001, 2-factor analysis of variance). Accumulating multiple short bouts of exercise throughout the day effectively reduce postprandial plasma triacylglycerol concentrations to an extent similar to that of a single 30-min session of exercise in healthy young men.
Article
To explore sex differences in the regulation of lipolysis during exercise, the lipid-mobilizing mechanisms in the subcutaneous adipose tissue (SCAT) of overweight men and women were studied using microdialysis. Subjects matched for age, BMI, and physical fitness performed two 30-minute exercise bouts in a randomized fashion: the first test at 30% and 50% of their individual maximal oxygen uptake (Vo(2max)) and the second test at 30% and 70% of their Vo(2max). In both groups, an exercise-dependent increment in extracellular glycerol concentration (EGC) was observed. Whatever the intensity, phentolamine [alpha-adrenergic receptor (AR) antagonist] added to a dialysis probe potentiated exercise-induced lipolysis only in men. In a probe containing phentolamine plus propranolol (beta-AR antagonist), no changes in EGC occurred when compared with the control probe when exercise was performed at 30% and 50% Vo(2max). A significant reduction of EGC (when compared with the control probe) was observed in women at 70% Vo(2max). At each exercise power, the plasma non-esterified fatty acid and glycerol concentrations were higher in women. Exercise-induced increase in plasma catecholamine levels was lower in women compared with men. Plasma insulin decreased and atrial natriuretic peptide increased similarly in both groups. Overweight women mobilize more lipids (assessed by glycerol) than men during exercise. alpha(2)-Anti-lipolytic effect was functional in SCAT of men only. The major finding is that during low-to-moderate exercise periods (30% and 50% Vo(2max)), lipid mobilization in SCAT relies less on catecholamine-dependent stimulation of beta-ARs than on an increase in plasma atrial natriuretic peptide concentrations and the decrease in plasma insulin.
The Authors Clinical Physiology and Functional Imaging Ó
  • K Goto
Multiple bouts of exercise on fat metabolism, K. Goto et al. Ó 2011 The Authors Clinical Physiology and Functional Imaging Ó 2011 Scandinavian Society of Clinical Physiology and Nuclear Medicine 31, 3, 215-220
Exercise prescription In: ACSMÕs Guidlines for Exercise Testing and Prescription
  • American College
  • Sports Medicine
American College of Sports Medicine. Exercise prescription. In: ACSMÕs Guidlines for Exercise Testing and Prescription, 7th edn (ed.Whaley MH) (2006), pp. 448-709.
215-220 intensity bicycling in trained young men
Ó 2011 The Authors Clinical Physiology and Functional Imaging Ó 2011 Scandinavian Society of Clinical Physiology and Nuclear Medicine 31, 3, 215-220 intensity bicycling in trained young men. J Clin Endocrinol Metab (2002); 87: 4966-4975.
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Acute growth hormone administration causes exaggerated increases in plasma lactate and glycerol during moderate to high Multiple bouts of exercise on fat metabolism
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  • A Flyvbjerg
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  • M Bennekou
  • Mh Rasmussen
  • H Orskov
  • M Kjaer
  • Goto
Lange KH, Larsson B, Flyvbjerg A, Dall R, Bennekou M, Rasmussen MH, Orskov H, Kjaer M. Acute growth hormone administration causes exaggerated increases in plasma lactate and glycerol during moderate to high Multiple bouts of exercise on fat metabolism, K. Goto et al.