The influence of a pre-exercise sports drink (PRX) on factors related to maximal aerobic performance

Abstract

Background

Pre-exercise sports drinks (PRX) are commonly used as ergogenic aids in athletic competitions requiring aerobic power. However, in most cases, claims regarding their effectiveness have not been substantiated. In addition, the ingredients in PRX products must be deemed acceptable by the athletic governing bodies that regulate their use in training and competition. The purpose of this study was to examine the effects of a modified PRX formulation (known as EM·PACT™) from earlier investigations on factors related to maximal aerobic performance during a graded exercise test. The modification consisted of removing creatine to meet the compliance standards set forth by various athletic organizations that regulate the use of nutritional supplements.

Methods

Twenty-nine male and female college students varying in levels of aerobic fitness participated in a randomized crossover administration of PRX (containing 14 g/serving of fructose, medium-chain triglycerides, and amino acids mixed with 8 oz. of water) and placebo (PL) 30 minutes prior to performing a treadmill test with approximately one week separation between the trials. VO₂max, maximal heart rate (HR), time to exhaustion (Time), and percentage estimated non-protein fat substrate utilization (FA) during two a priori submaximal stages of a graded exercise testing were evaluated.

Results

The VO₂max mean value of the PRX trial was significantly greater than the PL trial (P < 0.01). The mean value for Time was also observed to be greater for the PRX trial compared to PL (P < 0.05). Additionally, percentage of FA during submaximal stages of the exercise test was greater for PRX trial in comparison to PL (P < 0.01).

Conclusions

The modified PRX formulation utilized in this investigation supports the findings of the previous investigation and its efficacy for enhancing indices of aerobic performance (specifically VO₂max, Time, & FA) during graded exercise testing.

Keywords:

• Gastric Emptying
• Endurance Athlete
• Aerobic Power
• Sport Drink
• Aerobic Performance

Electronic supplementary material

The online version of this article (doi:10.1186/1550-2783-7-12) contains supplementary material, which is available to authorized users.

Electronic supplementary material

The online version of this article (doi:10.1186/1550-2783-7-12) contains supplementary material, which is available to authorized users.

Acknowledgements

Gratitude is expressed by the authors to Mannatech, Incorporated for funding this research project. In addition, the authors would like to thank the many subjects who volunteered their time and energy to participate in this study.

Competing interests

The authors declare that they have no competing interests.

Authors' contributions

AB developed the concept of the study, contributed to its design, data collection, statistical analysis, and manuscript preparation. SK & WK contributed in the design of the study, data collection, and manuscript preparation. AM & MG provided background work for the manuscript and contributed to its preparation.

All authors have read and approved the final manuscript.