Improvement of Sprint Performance in Wheelchair Sportsmen With Caffeine Supplementation

Purpose: Caffeine can be beneficial during endurance and repeated-sprint exercise in able-bodied individuals performing leg or whole body exercise. However, little evidence exists regarding its effects during upper-body exercise. This study therefore aimed to investigate the effects of caffeine on sprint (SPR) and 4-min maximal-push (PUSH) performance in wheelchair sportsmen. Methods: Using a double-blind, placebo-controlled, crossover design, 12 male wheelchair rugby players (age 30.0 +/- 7.7 y, body mass 69.6 +/- 15.3 kg, training 11.1 +/- 3.5 h/wk) completed 2 exercise trials, separated by 7-14 d, 70 min after ingestion of 4 mg/kg caffeine (CAF) or dextrose placebo (PLA). Each trial consisted of four 4-min PUSHes and 3 sets of 3 x 20-m SPRs, each separated by 4 min rest. Participants responded to the Felt Arousal (a measure of perceived arousal), Feeling (a measure of the affective dimension of pleasure/displeasure), and rating-of-perceived-exertion (RPE) scales. Salivary caffeine secretion rates were measured. Results: Average SPR times were faster during CAF than PLA during SPR 1 and SPR 2 (P=.037 and .016). There was no influence of supplementation on PUSHes 2-4 (P>.099); however, participants pushed significantly farther during PUSH 1 after CAF than after PLA (mean +/- SD 677 +/- 107 and 653 +/- 118 m, P=.047). There was no influence of CAF on arousal or RPE scores (P>.132). Feeling scores improved over the course of the CAF trial only (P=.017) but did not significantly differ between trials (P>.167). Pre-warm-up (45 min postingestion) salivary CAF secretion rates were 1.05 +/- 0.94 and 0.08 +/- 0.05 mu g/min for CAF and PLA, respectively. Conclusion: Acute CAF supplementation can improve both 20-m-sprint performance and a 1-off bout of short-term endurance performance in wheelchair sportsmen.