In a randomized, double-blind study with10 moderately trained male athletes, it was found that caffeine ingestion may improve performance when athletes are both fresh and fatigued. Compared to placebo participants, individuals taking a 6mg/kg dose of caffeine 60 min before completing an 80-min (4 × 20 min) simulated team-game reported increased total time by 2.3%, reactive agility by 3.9%, movement time by 2.7%, decision time by 9.3%, and decision-making accuracy by 3.8% compared to placebo. However, the results were not significant. (7)
A study found that caffeine or sodium bicarb enhanced cycling performance but combining both did not result in further benefit. Ten well-trained cyclists (mean age, 24.2 yr) participated in this double-blind, crossover study that involved four 3-km cycling time-trial (TT) on a laboratory-based cycle ergometer performed on separate days. Before each TT, participants took either 3 mg/kg body mass (BM) of caffeine (CAFF), 0.3 g per kilogram of sodium bicarbonate (SB), a combination of the two (CAFF+SB), or a placebo (PLAC). Findings indicate that when taken individually, both CAFF and SB enhance high-intensity cycling TT. However, the effect on enhancing physical performance of these 2 popular supplements when taken together was not additive. (8)