Fig. 2

Subjective measures. a – c: Changes in subjective energy (a), focus (b) and fatigue (c) were assessed as the difference between visual analog scale scores between baseline and subsequent measurements. d: Ratings of perceived exertion were assessed after each exercise set using the repetitions-in-reserve method. Pre and post designations refer to pre-supplementation and post-supplementation assessments. A significant time main effect was present, and time points with different letter designations are significantly different from each other (p < 0.05)