The Effects of a Commercially Available Energy Drink on Vertical Jump Performance

Abstract

Energy drinks are often marketed to the consumer as a performance enhancing beverage. When performance benefits are realized, it is likely due to the caffeine content present in typical energy drinks. There have been few if any scientific studies investigating the effects of energy drink ingestion on anaerobic power performance. PURPOSE: To determine the effects of a caffeine-containing, commercially available energy drink on an anaerobic power vertical jump test. METHODS: In a randomized (order of beverage), double blind, placebo controlled cross-over design, 15 recreationally active subjects (9 males and 6 females; 21.7 ± 1.6 yrs; 172.7 ± 10.3 cm; 75.1 ± 20.2 kg) ingested a commercially available energy drink (containing 160mg of caffeine) or a placebo beverage that was matched for carbohydrate content and was similar in volume and texture. The average relative caffeine dosage for each participant was 2.1 mg/kg. Forty-five minutes following ingestion of the energy drink or carbohydrate placebo, each participant engaged in a vertical jump test (Vertical Challenger®). Prior to the vertical jump test, each participant was instructed to lightly jog for approximately 90 seconds and then perform a vertical jump at 50 and 75% of maximum effort. These activities served as a warm-up prior to the maximal vertical jump attempts. Following the warm-up, each participant attempted three maximal vertical jumps with each one separated by approximately 90 seconds. The highest vertical jump recorded was used for statistical analysis. Vertical jump performance was analyzed via within-subjects repeated measures ANOVA using SPSS for Windows 15.0. RESULTS: Vertical jump performance was 21.4 ± 6.7 inches forty-five minutes following energy drink ingestion and 21.1 ± 6.6 inches forty-five minutes following placebo ingestion. The repeated measures ANOVA analysis revealed that there was not a significant difference between the energy drink and placebo beverage (p = .290). CONCLUSIONS: Ingesting a caffeine-containing energy drink forty-five minutes prior to performing a vertical jump will not improve vertical jump performance. PRACTICAL APPLICATIONS: Energy drink ingestion has been shown to improve certain types of exercise performance such as reaction time, chest press total lifting volume, and peak power on a Wingate test. In relation to anaerobic power exercise performance (such as the vertical jump test), however, there are few if any studies investigating the effects that energy drink consumption exerts. The present study indicated that a caffeine-containing energy drink did not improve vertical jump performance. ACKNOWLEDGMENT: This investigation was supported by a University of South Florida College of Education Mini-Grant.