Search Results

You are looking at 1 - 10 of 1,046 items for :

  • "supplement" x
Clear All
Restricted access

Yoshiharu Shimomura, Asami Inaguma, Satoko Watanabe, Yuko Yamamoto, Yuji Muramatsu, Gustavo Bajotto, Juichi Sato, Noriko Shimomura, Hisamine Kobayashi and Kazunori Mawatari

The authors examined the effect of branched-chain amino acid (BCAA) supplementation on squat-exercise-induced delayed-onset muscle soreness (DOMS) using 12 young, healthy, untrained female participants. The experiment was conducted with a crossover double-blind design. In the morning on the exercise-session day, the participants ingested either BCAA (isoleucine:leucine:valine = 1:2.3:1.2) or dextrin at 100 mg/kg body weight before the squat exercise, which consisted of 7 sets of 20 squats/set with 3-min intervals between sets. DOMS showed a peak on Days 2 and 3 in both trials, but the level of soreness was significantly lower in the BCAA trial than in the placebo. Leg-muscle force during maximal voluntary isometric contractions was measured 2 d after exercise (Day 3), and the BCAA supplementation suppressed the muscle-force decrease (to ~80% of the value recorded under the control conditions) observed in the placebo trial. Plasma BCAA concentrations, which decreased after exercise in the placebo trial, were markedly elevated during the 2 hr postexercise in the BCAA trial. Serum myoglobin concentration was increased by exercise in the placebo but not in the BCAA trial. The concentration of plasma elastase as an index of neutrophil activation appeared to increase after the squat exercise in both trials, but the change in the elastase level was significant only in the placebo trial. These results suggest that muscle damage may be suppressed by BCAA supplementation.

Restricted access

Allen C. Parcell, Jason M. Smith, Shane S. Schulthies, J. William Myrer and Gilbert Fellingham

It is purported that supplementation with Cordyceps Sinensis (CordyMax Cs-4) will improve oxidative capacity and endurance performance. The intent of this investigation was to examine the effects of CordyMax Cs-4 supplementation on VO2peak, ventilatory threshold, and endurance performance in endurance-trained cyclists. Twenty-two male cyclists participated in 5 weeks of supplementation with CordyMax Cs-4 tablets (3 g/d). Training intensity was maintained by weekly documentation and reporting throughout the 5-week period. Subjects completed a VO2peak test and work-based time trial prior to and following the supplementation period. VO2peak was similar within and between placebo (PLA) and treatment (CS) groups prior to (59.9 ± 5.9 vs. 59.1 ± 5.4 ml/kg/min, respectively) and following (60.1 ± 5.5 vs. 57.1 ± 5.8 ml/kg/min, respectively) the supplementation period. Ventilatory threshold (VT) was measured at 72 ± 10% of VO2peak in P and T prior to supplementation and did not change in either group following the supplementation. PLA completed the time trial in 61.4 ± 2.4 min compared to 62.1 ± 4.0 min in T. Time trial measurements did not differ between groups, nor did they change in response to supplementation. It is concluded that 5 weeks of CordyMax Cs-4 supplementation has no effect on aerobic capacity or endurance exercise performance in endurance-trained male cyclists.

Open access

International Olympic Committee Expert Group on Dietary Supplements in Athletes

Dietary supplements encompass a wide range of products, including essential nutrients (vitamins, minerals, proteins, amino acids, etc.), herbals and botanicals, and specific products with potential for maintenance of health and optimisation of performance. The use of dietary supplements is

Restricted access

Samuel T. Howe, Phillip M. Bellinger, Matthew W. Driller, Cecilia M. Shing and James W. Fell

Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this randomized double-blind placebo-controlled study was to examine the effects of beta-alanine supplementation on aspects of muscular performance in highly trained cyclists. Sixteen highly trained cyclists (mean ± SD; age = 24 ± 7 yr; mass = 70 ± 7kg; VO2max = 67 ± 4ml·kg−1·min–1) supplemented with either beta-alanine (n = 8, 65 mg·kg−1BM) or a placebo (n = 8; dextrose monohydrate) over 4 weeks. Pre- and postsupplementation cyclists performed a 4-minute maximal cycling test to measure average power and 30 reciprocal maximal isokinetic knee contractions at a fixed angular velocity of 180°·sec−1 to measure average power/repetition, total work done (TWD), and fatigue index (%). Blood pH, lactate (La) and bicarbonate (HCO3 -) concentrations were measured preand postisokinetic testing at baseline and following the supplementation period. Beta-alanine supplementation was 44% likely to increase average power output during the 4-minute cycling time trial when compared with the placebo, although this was not statistically significant (p = .25). Isokinetic average power/repetition was significantly increased post beta-alanine supplementation compared with placebo (beta-alanine: 6.8 ± 9.9W, placebo: –4.3 ± 9.5 W, p = .04, 85% likely benefit), while fatigue index was significantly reduced (p = .03, 95% likely benefit). TWD was 89% likely to be improved following beta-alanine supplementation; however, this was not statistically significant (p = .09). There were no significant differences in blood pH, lactate, and HCO3 between groups (p > .05). Four weeks of beta-alanine supplementation resulted in worthwhile changes in time-trial performance and short-duration muscular force production in highly trained cyclists.

Open access

Ronald J. Maughan, Susan M. Shirreffs and Alan Vernec

Athletes use dietary supplements in the hope or expectation of a beneficial effect, which, for the elite athlete, generally means a positive effect on competitive performance. Such an effect may be achieved directly, by a specific effect on performance in competition, or indirectly by better health

Open access

Ina Garthe and Ronald J. Maughan

Many athletes, at all levels of competition, place great emphasis on the use of dietary supplements, but of all the factors that determine athletic performance, supplements can play only a very small role. Compared with factors such as talent, training, tactics, and motivation, nutrition has a

Open access

Romain Meeusen and Lieselot Decroix

stimuli to recall memorial representations of experiences with particular food items. These memorial representations can be pleasant or unpleasant (e.g., conditioned food/taste aversion). It is clear that nutrition (and supplements) will influence brain functioning. Nutrition provides the proper building

Restricted access

Ahmed Ismaeel, Michael Holmes, Evlampia Papoutsi, Lynn Panton and Panagiotis Koutakis

ROS ( Steinbacher & Eckl, 2015 ). Notably, consumption of antioxidant supplements has become a very common practice for athletes and physically active individuals in a perceived attempt to enhance training, speed up recovery, and limit muscle damage and soreness ( Gomez-Cabrera et al., 2008

Open access

Ronald J. Maughan, Louise M. Burke, Jiri Dvorak, D. Enette Larson-Meyer, Peter Peeling, Stuart M. Phillips, Eric S. Rawson, Neil P. Walsh, Ina Garthe, Hans Geyer, Romain Meeusen, Luc van Loon, Susan M. Shirreffs, Lawrence L. Spriet, Mark Stuart, Alan Vernec, Kevin Currell, Vidya M. Ali, Richard G.M. Budgett, Arne Ljungqvist, Margo Mountjoy, Yannis Pitsiladis, Torbjørn Soligard, Uğur Erdener and Lars Engebretsen

Dietary supplements are used by athletes at all levels of sport, reflecting the prevalence of their use in the wider society. About half of the adult US population uses some form of dietary supplements ( Bailey et al., 2011 ) and, though there are regional, cultural, and economic differences, a

Restricted access

Gabriel Motta Pinheiro Brisola, Elvis de Souza Malta, Paulo Roberto Pereira Santiago, Luiz Henrique Palucci Vieira and Alessandro Moura Zagatto

, 2 and a decrease in time spent in sprints and other high-intensity actions (from 18.1% to 12.6%). 7 In this way, some studies have recently used β-alanine supplementation in water polo 8 – 10 in an attempt to avoid the deleterious effects of acidosis on muscle, and some positive findings were