Effect of an Energy Drink on Physical and Cognitive Performance in Trained Cyclists

Abstract

Dedication This work is dedicated to those who have supported me outside of my graduate studies over the last few years. My family deserves as much credit as anyone for the work generated as part of this study. Namely, Kristin Bagby, Christine Lassiter, Mechelle Lassiter, Bette Rose Ryan, and Michele Poague deserve recognition; without them I would not have been able to work as tirelessly as I have on this project. v Acknowledgements Many individuals contributed significantly to the completion of this project. Though the thesis is my own, the project is a result of a team effort. First and foremost Lynne Kammer helped me every step of the research process, from study design, to data collection, and proofreading. Zhenping Ding played another critical role in training and overseeing the completion of the biochemistry techniques used as part of this work. Assays were completed is listed last, his help on this and other projects that I have been a part of is understated and I commend him for being such a hard-working and loyal individual. My graduate studies have been made possible through the concerted efforts of the entire kinesiology staff at the University of Texas and I would like to recognize the contributions to my education made by Ivy have served as readers for my thesis and for this I owe them recognition. Lastly I would like to thank the sponsor of my research, SWSS law, and the participants who were willing to ride their bikes in the lab for the sake of expanding our scientific understanding. vi Abstract Effect of an Energy Drink on Physical and Cognitive Performance in Trained Cyclists David Gray Lassiter, MS KIN The University of Texas at Austin, 2012 Supervisor: John Ivy This study investigated the effectiveness of an energy drink (ED) in enhancing cycling time-trial performance, and cognitive performance at rest, during moderate-intensity exercise, and after exercise. The protocol was double-blind, randomized, placebo-controlled, two-period, and within-subjects. The treatments were ED containing caffeine and carbohydrate, and a caffeine-free non-caloric flavored placebo beverage (PLA). Exercise performance was measured by time to finish a simulated 35 km time-trial course. Cognitive performance was measured by a Stroop task, a tapping task, a reaction time task, and an executive function task consisting of both tapping and reaction time. The effects of ED on blood markers were also assessed. Race performance was enhanced by an average of 3% when participants had ED compared to PLA without a difference in rating of perceived exertion (RPE). Performance was improved by ED even in participants that arrived to the lab with elevated blood caffeine concentrations. Both before and after the exercise, ED resulted in more taps per second in the tapping task. After receiving ED, plasma insulin spiked, there was a fall in free fatty acids (FFA) and vii blood glucose remained unchanged. Exercise onset caused a drop in blood glucose when participants consumed ED, though glucose returned to a level that was not di...

Effects of Energy Drinks on Economy and Cardiovascular Measures

“…Caffeine is the primary ingredient found within energy drinks that may alter performance and cardiovascular measures. Caffeine is a psychoactive drug known to allay fatigue and improve endurance performance and is one of the most widely used drugs in the world (6,8,10,15,21,22,25,27,34). In previous research caffeine has been shown to improve performance (8,10,15,21,22,25,34).…”

Energy drink and energy shot use in the military

“…The use of energy drinks and energy shots is high among US military personnel and has been a subject of ongoing controversy for several years . Proponents claim that energy drinks improve athletic performance . Given that the primary active ingredient in most energy products is caffeine, this is expected, since caffeine is a known ergogenic aid for endurance and anaerobic activities .…”

Caffeinated Nitric Oxide-releasing Lozenge Improves Cycling Time Trial Performance

“…Ingestion of as low as 3 mg/kg body weight 1 h before exercise has been found to be effective at increasing exercise time to exhaustion at exercise intensities of 70-80 % maximal oxygen consumption (VO 2 max) [17,28]. However, energy drinks containing much lower amounts of caffeine have also been found to have effective ergogenic properties [16,21]. The reasons behind the ergogenic effects of caffeine, however, are not clear, but have been associated…”

“…However, there is the possibility that providing the caffeine with a NO source improved the efficacy of the caffeine. Previous research with energy drinks containing relatively low levels of caffeine have been found to improve cycling time trial performance without an increase in perceived effort [16,21]. Improvements in aerobic performance by increasing blood nitrate levels either by consumption of sodium nitrate or beetroot juice has been associated with an increase in oxygen efficiency [2,3,19,20].…”