Caffeine and resistance exercise: the effects of two caffeine doses and the influence of individual perception of caffeine

Abstract

Although caffeine is a widely used ergogenic resource, some information regarding its effects on resistance exercises is still lacking. The objective of the present study was to verify the acute effect of the ingestion of two different doses of caffeine on performance during a session of resistance exercises and to analyze the perception of the subjects in relation to the intake of caffeine. Following a double-blind, randomised, cross-over, controlled, and non-placebo design, 14 trained and healthy men (24.7 ± 6.8 years; 79.8 ± 9.8 kg; 177.3 ± 8.5 cm) performed a training session in chest-press, shoulder-press, and biceps curl exercises (3 sets until exhaustion; 70% 1RM; 3 min rest interval; 2 s for each concentric and eccentric phase) on three non-consecutive days after ingestion of 3 mg.kg −1 caffeine (CAF3), 6 mg.kg −1 caffeine (CAF6), or no substance (CON). Subjects were informed that one of the caffeine doses would be placebo. The total number of repetitions performed in CON (93.6 ± 22.4) was significantly lower than in CAF3 (108.0 ± 19.9, P = 0.02) and in CAF6 (109.3 ± 19.8, P = 0.03) and there were no differences between caffeine doses. Eight subjects noticed that caffeine was in CAF3 and six in CAF6 and there were no differences in the number of repetitions between sessions in which the subjects perceived and did not perceive caffeine. In conclusion, caffeine doses of 3 or 6 mg.kg −1 similarly increased performance in resistance upper limb exercises, independent of the subject's perception of substance ingestion.

What Dose of Caffeine to Use: Acute Effects of 3 Doses of Caffeine on Muscle Endurance and Strength

“…Thus far, only Polito and colleagues 24 conducted a study that had a similar design to ours. In this study, 14 resistance-trained men performed three upper-body resistance exercises (chest press, shoulder press, and biceps curl exercises) for three sets until exhaustion with 70% of 1RM after the ingestion of either 3 or 6 mg .…”

“…The reason for the discrepancies between the studies could be related to the protocol used. In the study by Polito et al 24 study, the participants performed a total of nine sets (three sets for each of the three exercises), whereas we used one 'all-out' set. Caffeine ingestion attenuates the fatigue-induced decline in muscle contractile properties, 25 which may explain why caffeine was effective for upper-body muscles over a multiple set protocol, as in the study by Polito and colleagues, but not when using a single set.…”

Effects of Caffeine on Resistance Exercise: A Review of Recent Research

“…Over 20 new studies explored the effects of caffeine on different muscular endurance outcomes [6,8,9,11,16,21,22,26,29,30,35,36,38,41,44,45,48,49,[52][53][54][55]]. An ergogenic effect of caffeine on muscular endurance was observed in the majority of these studies, with the effect sizes ranging from small to large (Cohen's d: 0.18-2.21).…”

Caffeine and Exercise Performance: Possible Directions for Definitive Findings

“…In these cases, the use of higher doses of caffeine could be triggering additional performance effects by increasing the calcium release from the sarcoplasmic reticulum (Klein et al, 1990;von Ruden and Neher, 1993). This hypothesis needs to be verified since there is also a recent study (Polito et al, 2019) indicating that the use of lower doses of caffeine (3 mg.kg −1 ) provides same improvements results in muscle strength (chest-press, shoulder-press, and biceps curl exercises) as the administration of moderate doses (6 mg.kg −1 ).…”