Differences in the effects of carbohydrate food form on endurance performance to exhaustion.

This investigation examined the metabolic and performance effects of ingesting solid compared to slurried carbohydrate food (bananas) between two prolonged exhaustive exercise bouts. Eight highly trained male triathletes performed four exhaustive endurance tests (ET), each separated by at least 2 weeks. Each ET consisted of a 90-min run followed by 90 min of cycling, both at 70% VO2max. Workloads were then gradually increased on the cycle, and subjects continued to cycle until exhausted. They then rested for 20 min and ingested one of the following: an artificially sweetened placebo drink (P), slurried bananas (SL), or solid bananas (SO). Bananas were given in equal portions relative to each subject's body weight. Subjects cycled to exhaustion a second time at 70% of their VO2max, at which point the mean blood glucose concentration for the combined carbohydrate treatments was significantly higher than that from the P treatment. The mean glucose concentration from the SL treatment did not differ significantly from the SO treatment. These data demonstrate that solid bananas are as effective as slurried bananas in maintaining plasma glucose and in enhancing endurance exercise performance.

Plasma amino acid responses of trained athletes to two successive exhaustion trials with and without interim carbohydrate feeding.

The purpose of this research was to measure changes in selected plasma amino acids (AA) during two successive exercise trials to exhaustion. Eleven trained male athletes completed these trials at weeks 4, 6, 8 and 12. Blood samples for each test were collected after a 12-hour fast at times (in minutes) 0 (Resting), 45, 90, 135, 180, at exhaustion (EI), after a 20-minute recovery period, and at the second exhaustion (EII). At the end of EI, subjects consumed an artificially sweetened water replacement (placebo) treatment or a carbohydrate (CHO) replacement (1.1 g CHO/kg BW) in order to determine any effect of CHO replacement on changes in energy substrates or AA, adjusted for plasma volume changes. From baseline to EI, alpha-aminobutyric acid, alanine, glycine, isoleucine, serine, valine threonine, and tyrosine decreased significantly (p less than or equal to 0.05), while taurine increased significantly. During the recovery period following EI, isoleucine, leucine, ornithine, phenylalanine, tyrosine, urea and valine increased significantly. From the end of recovery until EII, alanine, aspartic acid, glycine, isoleucine, leucine, ornithine, phenylalanine, serine, threonine, tyrosine and valine decreased significantly. CHO replacement had no effect on the mean change scores for any AA from EI to the end of the recovery period and affected only serine, citrulline, glycine and threonine from the end of the recovery period to EII.

Effects of coenzyme athletic performance system as an ergogenic aid on endurance performance to exhaustion.

This study examined the effects of the Coenzyme Athletic Performance System (CAPS) on endurance performance to exhaustion. CAPS contains 100 mg coenzyme Q10, 500 mg cytochrome C, 100 mg inosine, and 200 IU vitamin E. Eleven highly trained male triathletes were given three daily doses of either CAPS or placebo (dicalcium phosphate) for two 4-week periods using a double-blind crossover design. A 4-week washout period separated the two treatment periods. An exhaustive performance test, consisting of 90 minutes of running on a treadmill (70% VO2max) followed by cycling (70% VO2max) until exhaustion, was conducted after each treatment period. The mean (+/- SEM) time to exhaustion for the subjects using CAPS (223 +/- 17 min) was not significantly different (p = 0.57) from the placebo trial (215 +/- 9 min). Blood glucose, lactate, and free fatty acid concentrations at exhaustion did not differ between treatments (p < 0.05). CAPS had no apparent benefit on exercise to exhaustion.