The Effects of a Sports Energy Drink on Female Collegiate Hockey Players

Abstract

The aim of this study was to examine the effects of ingesting a carbohydrate-electrolyte solution on repeated sprint running performance. Fourteen trained female Hockey players performed two exercise trials, 7 days apart. On each occasion, they completed just under 20 minutes of exercise, comprising a 15 minute warm up and the < 5 minutes taken to complete the repeated sprint exercise test. The subjects were allocated either a 5.6% carbohydrate solution (S1) or a non-carbohydrate placebo (S2) 10 minutes before the onset of the warm up. For each trial sprint times were recorded using photoelectric cells linked to a digital timing system. Fatigue indices were calculated for all subjects by finding the percentage decrease in sprint time between the fastest and following slowest sprint. Heart rate was recorded for the duration of the bout of repeated sprints. Dehydration levels were ascertained by calculating the absolute and percentage loss of weight prior to the warm up phase and post exercise test phase. Borg ratings of perceived exertion were attained at intervals over the duration of the test and means calculated. Statistical analysis found there to be no significant difference in mean fatigue index (11.98 ± 4.95%; 12.16 ± 4.42%), mean sprint times (7.04 ± 0.09; 7.08 ± 0.09), mean fluid losses (0.17 ± 0.12; 0.13 ± 0.11) mean Borg ratings of perceived exertion (14.6 ± 1.3 and 14.2 ± 1.1) and heart rate (172 ± 8 and 171 ± 5) between S1 and S2 trials respectively.

In conclusion it was established that sports drinks were ineffective at significantly reducing fatigue, during a bout of repeated sprints and other performance parameters were also shown not to be significantly affected. Although 50% were shown to fatigue less after the ingestion of the sports drink, it could not be ascertained as to whether this was the effect of the beverage or other uncontrolled variables. With an absence of all participants displaying positive performance effects with a sports drink, this study puts into question the persuasive marketing ploys used by many of these companies.