Only one subject dropped out after the initial baseline. At the completion of the experimental trial, six subjects correctly identified the order of ED vs. placebo, four did not, and five were not sure. Figure 1 Respiratory exchange ratio vs. exercise intensity as a percentage of ventilatory threshold (% of VT) for energy drink and placebo conditions. Values are mean ± standard deviation. Only 30% of VT intensity was different from experimental vs. placebo (*p < 0.046). Discussion This was

the first study to investigate preexercise ingestion of the ED Monster in relation to ride TTE and cardiovascular parameters. Cardiovascular parameters at rest did show an increase in HR after consuming the ED, but there were no changes in any HRV parameters. Ride TTE during cycle

ergometery testing, peak RPE, and peak HR during exercise were not different between the two conditions. The RER measurements during each intensity were not different between the two conditions, find more except for the RER at 30% of VT where the placebo condition was lower. Exercise effects The main finding in this study is consistent with data by Candow et al. [14] who conducted a high-intensity run TTE study in young adults (VO2max of 45.5 ± 6.3 ml • kg–1 • min–1) using a double-blind, crossover, repeated-measures method. They showed no increase in run time or change in RPE with the energy drink Red Bull given preexercise. However, VX-680 supplier Ivy et al. [10] did see an improvement with preexercise Red Bull. Their study also used

a double-blind, randomized, crossover design, but was conducted in athletes with a higher VO2max (54.9 ± 2.3 ml • kg–1 • min–1) and employed a time trial format. Kazemi et al. [32] demonstrated that Phantom and Dragon energy drinks also significantly increased check TTE vs. placebo by 9.3% and 6.5% respectively during a Bruce treadmill test. Caffeine One reason for the lack of increased ride time was possibly the lower dose of caffeine standardized at 2 mg · kgBM-1. The recent International Society of Sports Nutrition (ISSN) NSC23766 molecular weight position stand on energy drinks [33] concluded that although they contain a number of nutrients, the primary ergogenic nutrients appear to be carbohydrate and/or caffeine. The exact mechanism of how caffeine works is still debated, but it is believed to primarily function by acting as an adenosine receptor antagonist, increasing release of free fatty acids, and increasing calcium release and uptake [34]. The track record of positive effects of caffeine is quite good and most studies showed an improvement in exercise capacity in the range of 3–13 mg · kgBM-1[9, 33, 35–40], although Cox et al. [41] did show a decreased time during a time trial performance undertaken at the end of a prolonged cycling bout with a low dose at approximately 1.5 mg · kgBM-1. Denadai, et al. [39] used a dose of around 3 mg · kgBM-1 and showed that in untrained subjects who exercised below their anaerobic threshold, caffeine increased ride TTE and reduced perceived exertion.