Background/Purpose: Caffeine is one of the commonly used pre-exercise supplements, yet limited research has examined the optimal timing of ingestion prior to resistance training. The aim of this study is to investigate the optimal timing of ingesting caffeine with habitual consumers prior to engaging in resistance training. Methods: Nine university students participated in one repetition maximum (1RM) testing to calculate the resistance at 70% of 1RM during their leg and bench press sets post caffeine (4 mg/kg) or placebo (flour) trials. Participants underwent four randomized trials including caffeine-ingestion 30-minute prior to exercise (CAF-30), placebo 30-minute prior (CON-30), caffeine 60-minute prior (CAF-60), and placebo 60-minute prior (CON-60). Participants completed these trials documenting three sets per exercise trial until failure. Heart rate (HR) and relative perceived exertion (RPE) were also noted. Results: Outcome measures were averaged across the three sets for leg and bench press repetitions, RPE, and a percent drop in number of repetitions from initial and final sets. A two-way repeated measures analysis of variance revealed no statistically significant difference in these outcome measures across the four trials, p > .05. Conclusions: Caffeine consumption 30-60 minutes prior to resistance training had no impact on muscular endurance, RPE, or fatiguability.
