Effects of caffeine mouth rinse on 10 km running time trial

Abstract

Purpose: This study investigates the effects of caffeine (CAF) mouth-rinse on 10 km running time trial. Methods: In this double-blinded, randomized, counterbalanced cross-over study, ten young and healthy men [mean age 26 (SD 4) years] completed three 10 km running sessions on the treadmill at a self-selected pace in the fastest time possible. Participants had a 5 min warm up, followed by a 30 s mouth-rinse. Thereafter, participants mouth-rinsed for 10 s for every 1 km of the run completed until the completion of the 10 km. For the first session, participants had a familiarization session using 25 ml of plain water to mouth-rinse. For the second and third sessions, participants were randomly given either 25 ml of 1.2% CAF or Placebo (PLA) solution to mouth-rinse during the experimental trials. Heart Rate (HR), Rate of Perceived Exertion (RPE), and time to complete the 10 km were measured during each session. Results: No significant differences (p = .279) in 10 km running time trial were observed between CAF [mean 63.32 (SD 6.98) min] and PLA [mean 64.26 (SD 6.02) min]. No significant differences were found in HR (p = .977) between CAF [mean 163 (SD 7) beats/min] and PLA [mean 163 (SD 10) beats/min]. RPE was not significantly different (p = .886) between CAF [median 13 (IQR 2)] and PLA [median 14 (IQR 4)]. Conclusion: CAF mouth-rinse did not significantly improve 10 km running time. HR and RPE did not differ significantly between trials. Keywords: Caffeine, mouth-rinse, running, endurance exercise, ergogenic