Impact Of Caffeine Supplementation On Aerobic Performance And Muscle Strength

Caffeine has been proven to be an effective ergogenic aid in aerobic exercise, but it is unclear if caffeine can simultaneously improve aerobic and strength performance. PURPOSE: The purpose of this investigation is to examine the impact of different levels of caffeine on aerobic performance and muscle strength. METHODS: Twelve participants (7 male, 5 female; age = 25.0 ± 1.3 years; weight = 78.6 ± 3.6 kg; height = 1.72 ± 3.54 m) completed four experimental sessions. During the first session, participants were familiarized with all procedures used in the experimental sessions. During the three experimental sessions, subjects completed the hand grip test and a 5-km time trial. Hand grip strength was assessed using the Jamar Plus Digital Hand Dynamometer. The 5-km time trial was completed on a Lode Corival CPET cycle ergometer. Prior to each experimental session, subjects consumed a 12-oz coffee beverage with decaffeinated coffee (PLAC), 220 mg (MID), or 450 mg (HIGH) of caffeine. Treatments were blinded to participants and applied in a randomized order. Subjects completed experimental sessions after a 4-hour food and 12-hour caffeine fast. RESULTS: Hand grip strength was greater during the HIGH (44.5 ± 3.6 kg) condition compared to PLAC (41.8 ± 3.2 kg) and MID (42.7 ± 3.2 kg) (p = 0.01). Subjects completed the 5-km time trial more quickly during the HIGH (6.1 ± 0.5 min) condition compared to PLAC (7.8 ± 1.0 min) (p = 0.03) and MID (7.5 ± 0.8 min) (p = 0.04). CONCLUSION: These findings indicate that the level of caffeine consumption can simultaneously impact anaerobic exercise performance and muscle strength.