The Effectiveness of a Pre-Exercise Performance Drink (PRX) on Indices of Maximal Cardiorespiratory Fitness

The Effectiveness of a Pre-Exercise Performance
Drink (PRX) on Indices of Maximal
Cardiorespiratory Fitness
Received May 5, 2006/Accepted June 6, 2006
Allyn Byars1, Mike Greenwood2, Lori Greenwood2, & Warren K. Simpson3
Journal of the International Society of Sports Nutrition

Department of Physical Therapy, Angelo State University, San Angelo, TX1; Exercise & Sport Nutrition Lab,
Baylor University, Waco, TX2, Department of Fitness and Sport Studies, Hardin-Simmons University, Abilene,
TX3. Address Correspondence to Allyn.Byars@angelo.edu

ABSTRACT
This study examined the effectiveness of a pre-exercise drink (PRX) called EM?PACT on indices of maximal
cardiorespiratory fitness. Twenty-four males (n=12) and females (n=12) ages 18-24 years (20.25 + 1.42),
volunteered as subjects. Each subject performed two randomized trials of a VO2max treadmill test within a week
of each other. Subjects in this randomized, placebo controlled, counter balanced, crossover design, ingested
either a placebo (water) or PRX 20 minutes before each exercise bout. VO2max and time to exhaustion (Time)
during graded exercise testing were evaluated. Using paired samples t-tests, significantly greater mean values
were found in VO2max and Time for the PRX trial compared to the placebo trial (p<.05). Results indicate that
indices of cardiorespiratory fitness; specifically VO2max and Time are enhanced by ingestion of PRX prior to
exercise testing. The combined results of this investigation may provide meaningful practical applications for
coaches and athletes alike regarding ergogenic hydration options. Journal of the International Society of
Sports Nutrition. 3(1):56-59, 2006

Key Words: sports nutrition, ergogenic aids, VO2max, aerobic performance, sport drink

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