Twelve of the 15 subjects were responders where improved performance during the SUP trial was observed. The magnitude of improvement in the responders ranged from 2.9 to 42.8%. The RER for all subjects was greater than 1.1 at the time of exhaustion. No significant difference in RER between trials was observed. Figure 1 Time to Exhaustion. * = significant difference between groups. VAS scores of subjective measures of focus,

energy and fatigue are presented in Table 1. Subjects consuming SUP reported significantly greater focus (p = 0.031), energy (p = 0.016), and less fatigue (p = 0.005) at PRE. Significant differences between groups were seen at EX10 for focus (p = 0.026) and energy (p = 0.004), but not fatigue (p = 0.123). No differences were seen at IP for either

focus (p = 0.215), energy (p = 0.717) or fatigue (p = 0.430). Table 1 PF-02341066 datasheet Visual Analog Scale Scores for Subjective Measures of Focus, Energy and Fatigue.     Focus Energy Fatigue PRE SUP 11.8 ± 1.9 11.7 ± 2.0 13.3 ± 2.8   P 10.5 ± 2.8* 10.5 ± 2.8* 11.6 ± 2.9* EX10 SUP 9.9 ± 3.1 9.7 ± 2.6 7.3 ± 3.4   P 7.6 ± 3.7* 6.1 ± 3.1* 6.4 ± 3.3 IP SUP 5.7 ± 5.0 3.2 ± 2.8 1.7 ± 1.8   P 3.8 ± 3.6 2.8 ± 3.3 2.2 ± 2.2 * = Significant difference between groups Discussion The results of this study indicate that an acute ingestion of the pre-exercise supplement Amino Impact™ containing caffeine, taurine, glucuronolactone, creatine, β-alanine, and the amino acids leucine, isoleucine, valine, glutamine and arginine can VRT752271 research buy enhance time to exhaustion during moderate-intensity endurance exercise. In addition, consumption

of this supplement 10-min prior to exercise appears to increase subjective feelings of focus, energy and reduce subjective feelings of fatigue before and during endurance exercise. The most commonly used ingredient in energy drinks is caffeine. MK5108 clinical trial Caffeine has been shown to be an effective ergogenic agent by delaying fatigue and increasing time to exhaustion during endurance exercise [5–9]. This is thought to be related to caffeine’s ability to enhance reliance on fat oxidation preserving muscle glycogen content [14]. Caffeine itself is only a mild central nervous system stimulator [15]. Therefore, additional ingredients (e.g., β-adrenergic receptor stimulators) are often combined with Ribonucleotide reductase caffeine to increase the stimulatory response and provide additional ergogenic benefits. The synergistic effect of these ingredients has been demonstrated to increase subjective feelings of alertness, focus and energy [16–19], and improve reaction time to both auditory and visual stimuli [16]. Taurine is often combined with caffeine in energy drinks. Although its mechanism of action is not well understood, previous studies have shown that taurine by itself can improve endurance performance [20, 21]. When combined with caffeine and glucuronolactone, ergogenic benefits of taurine have been confirmed in some investigations [12, 13], but not others [22].