Abstract des Autors

The purpose of this study was to examine the effects of sports drinks on sports performance. Female subjects (n=8) volunteered to participate in the study. Subjects wer required to perform two running tests. A 40m maximal shuttle run test (Baker, Ramsbottom & Hazeldine, 1993) to evaluate anaerobic fitness and a 20m shuttle run test for aerobic fitness (L�ger & Lambert, 1982). Prior to each testing session and once on each of the two days preceding testing sessions, subjects consumed one of the following: (1) a water placebo, (2) Isostar (Assumed performance enhancing drink) or (3) Glycosport (Assumed performance enhancing drink). No significant differences (F = 3.051, p < 0.05), F = 3.555, p << 0.05), F = 0.021, p < 0.05) were found between the treatments for fatigue index, fastest sprint times or slowest sprint times respectively. Fastest sprint times were 9.36 (0.7s), 9.51 (0.5s), 9.69 (0.5s), while values for slowest times were 10.38 (0.6s), 10.40 (0.4s), 10.36 (0.4s). Fatigue indexes observed during the study were 9.37 (16.7%), 7.12 (2.9%), 5.16 (16.7%) for the water placebo, Isostar and Glycosport respectively. In the 20MST subjects ingesting Isostar produced significantly (F = 4.589, p< 0.05) lower maximum heart rates, 195 (6.26 bt/min), in comparison to the water placebo, 199 (5.35 bt/min). However, there were no significant differences (F = 2.807, p < 0.05) in predicted VO2max scores, 41.97 (4.96 ml/kg/min), 42.92 (5.7 ml/kg/min), 39.81 (6.3 ml/kg/min). The data obtained in this experiment provides evidence that Isostar and Glycosport have no beneficial effect on performance in this type of exercise. Verf.-Referat