Sublingual Caffeine Supplementation on Physical Performance in United States Military Personnel [open pdf - 215KB]
From the abstract: "The objectives of this study were to measure the effects of sublingual caffeine ingestion on physical performance and perceptions of fatigue on highly fit military personnel and on neuromuscular function, specifically reaction time, following physically demanding work common to military personnel operating in the field. Results of this pilot study indicate that no difference occurred in the outcomes measured in subjects at baseline, placebo, or treatment groups. Although subjects may have differed in physical ability, each subject served as his/her own control, which was accounted for in the linear mixed model analysis. Physiological parameters measured included the following: (1) exercise heart rate, (2) muscular strength, power, and endurance, (3) neuromuscular function, (4) subjective rating of perceived exertion, (5) exercise heart rate, and (6) blood lactate. The results of this study show that caffeine at low doses (i.e., 6 mg/kg bodyweight) does not negatively impact physical or neuromuscular performance outcomes, even after engaging in muscle-fatiguing exercise (i.e., pullups, pushups, weighted vest walking test). Subjects showed consistent performance across all three groups and had similar responses (i.e., pushups in round 1 were greater than rounds 2 and 3 both pre- and post-treadmill walking)."
Defense Technical Information Center (DTIC): http://www.dtic.mil/dtic/