Search Results

This study investigated the effect of initial muscle glycogen on performance of repeated sprints and some potential mechanisms for an effect of glycogen on fatigue. Eight subjects performed 2 cycling trials (repeated 60-s sprints) following consumption of either a high carbohydrate (HC) or a low carbohydrate (LC) diet. Muscle biopsies and blood samples were collected at baseline, following a 15% (15% fatigue) and a 30% decline in sprint performance (30% fatigue), when exercise was terminated. Baseline muscle glycogen levels [346 ± 19 HC (SEM) vs. 222 ± 19 mmol/kg dw LC] and total exercise time to 30% fatigue were higher following HC than LC (57.5 ± 10.0 vs. 42.0 ± 3.6 min; p < .05). Similar significant (p < .05) decreases over the entire exercise bout were seen in muscle glycogen (43%), creatine phosphate (CP; 35%), and sarcoplasmic reticu-lum (SR) Ca²⁺-uptake in isolated homogenized muscle (56%) for both trials (p > .05 between trials). The percentage decline in SR Ca²⁺-release was less for HC than LC (36% and 53%, respectively), but this was not statistically different. In summary, HC delayed fatigue during repeated sprints. As the reductions in muscle glycogen, CP, and SR function during exercise were not different by dietary treatment, these data do not support a link between whole muscle glyco-gen and SR function or CP reduction during repeated sprint exercise.

The purpose of this investigation was to assess nutrition knowledge, opinions, and practices of coaches and trainers at a Division I university. Participants (n = 53) completed questionnaires regarding nutrition knowledge, opinions, and practices. Descriptive statistics and analysis of variance were used to analyze data. Overall, participants responded correctly to 67% of nutrition knowledge questions. Participants who coached/trained female athletes tended to score better than respondents who coached/trained male athletes. Strength and conditioning coaches and participants with greater than 15 years of experience scored higher than other participants. Nutrition opinions/practices responses revealed that nutritional supplements were provided for all but 6% of participants’ athletes. Participants rated body weight as more important than body composition to athletes’ performances. Over 30% of participants perceived at least one case of disordered eating within the past year. Some participants (53%) felt that athletes may consume more nutritious meals on team-sponsored trips if given larger food allowances. Thirty percent of participants reported dietitians were available to them; the same percentage reported utilizing dietitians. Coaches and trainers are knowledgeable about some appropriate nutritional recommendations, but registered dietitians or qualified sports nutrition professionals may complement the nutrition-related education and counseling of athletes (23).