Figure 3From: Skill execution and sleep deprivation: effects of acute caffeine or creatine supplementation - a randomized placebo-controlled trialPre-trial salivary free testosterone (pg/ml) across treatments. The mean ± SD is displayed for salivary testosterone under different treatment conditions (placebo; 1 or 5 mg/kg caffeine, 50 or 100 mg/kg creatine) either in non-sleep deprived or sleep deprived states. The 100 mg/kg creatine dose was associated with a higher concentration of testosterone (a) (p = 0.067) compared to the placebo treatment.Back to article page