Effects of Caffeine on Resistance Training Performance on Repetitions to Failure

Abstract

Background:

The purpose of this study was to evaluate the effects of caffeine (CA) on multiple resistance training bouts on repetitions to failure.

Methods:

Resistance-trained men (n=10) completed a double-blind, placebo (PL) controlled, randomized trial. A 10-repetition maximum was established to individualize workload. Participants completed two trials (4 sets to failure, 6 exercises [24 sets total]) including bench press, lat pulldown, shoulder press, bicep curl, tricep pushdown, and leg press following CA (6 mg·kg⁻¹) or PL ingestion 1 hour prior to the trial (counterbalanced). Exercises were performed to failure (2-minute recovery between sets/exercises). Ratings of perceived exertion (RPE) (0–10 omnibus and is nit expanded on (OMNI) scale) was recorded after every set and session-RPE (S-RPE) was recorded 20 minutes after each trial.

Results:

For total repetitions per exercise, a 2-way (PL vs. CA) repeated measures analysis of variance revealed a significant main effect of CA on performance (p≤0.01). Post hoc analyses showed a significant difference for total repetitions with bench press (p=0.03) but no significant difference for lat pulldown, shoulder press, bicep curl, tricep pushdown, or leg press (CA vs. PL). No significant effect was observed (p=0.24) for total repetitions for all exercises and sets combined compared with PL. Post hoc analyses revealed significantly greater repetitions (p=0.003) for bench press (set 4) with CA. However, no significant difference was found for any other set (p>0.05). RPE was significantly higher for tricep pushdown (p=0.002) for CA versus PL. No significant difference was shown for RPE for all other exercises (p>0.05) or S-RPE (p=0.44) with CA (8.1±0.8) versus PL (7.9±0.9).

Conclusions:

Results indicate that CA did not improve overall resistance training performance.