The effects of low and moderate doses of caffeine supplementation on upper and lower body maximal voluntary concentric and eccentric muscle force

Abstract

Despite the growing quantity of literature exploring the effect of caffeine on muscular strength, there is a dearth of data that directly explores differences in erogenicity between upper and lower body musculature and the dose-response effect. The present study sought to investigate the effects of low and moderate doses of caffeine on the maximal voluntary strength of the elbow flexors and knee extensors. Ten nonspecifically strength-trained, recreationally active participants (aged 21 ± 0.3 years) completed the study. Using a randomised, counterbalanced, and double-blind approach, isokinetic concentric and eccentric strength was measured at 60 and 180°/s following administration of a placebo, 3 mg·kg body mass caffeine, and 6 mg·kg body mass caffeine. There was no effect of caffeine on the maximal voluntary concentric and eccentric strength of the elbow flexors, or the eccentric strength of the knee extensors. Both 3 and 6 mg·kg body mass caffeine caused a significant increase in peak concentric force of the knee extensors at 180°/s. No difference was apparent between the 2 concentrations. Only 6 mg·kg body mass caused an increase in peak concentric force during repeated contractions. The results infer that the effective caffeine concentration to evoke improved muscle performance may be related to muscle mass and contraction type. The present work indicates that a relatively low dose of caffeine treatment may be effective for improving lower body muscular strength, but may have little benefit for the strength of major muscular groups of the upper body.

The Influence of Caffeine Supplementation on Resistance Exercise: A Review

“…Some studies have reported that caffeine ingestion decreases pain perception but without any significant effects on performance [27,37]. Tallis and Yavuz [41] and Sabblah et al [42] did not observe any significant reductions in pain perception, although caffeine ingestion increased muscular strength, suggesting that factors other than the reduced perception of pain contributed to the ergogenic effect. Although two studies reported that improvements in performance were accompanied by a decrease in pain perception [28,29], there was also a decrease in RPE that made it difficult to determine exactly what contributed to the ergogenic effect.…”

“…Using the same doses, Arazi et al [37] observed that caffeine did not improve leg press strength and muscular endurance at either 2 or 5 mg•kg -1 doses. Tallis and Yavuz [41] observed that both 3 and 6 mg•kg -1 caffeine doses were effective for increasing lower-body strength. Furthermore, as stated earlier when discussing power outcomes (section 5), three studies [68][69][70] have investigated the effects of 3 mg•kg -1 of caffeine on resistance exercise performance and power and suggested that this dose can be ergogenic.…”

“…Recently, Tallis and Yavuz [41] reported that caffeine ingestion enhanced isokinetic strength in the knee extensors but not in the elbow flexors, adding to the evidence showing that benefits of supplementation might be related to the different activation of smaller versus larger muscle groups. The results by Tallis and Yavuz [41] for isokinetic strength were confirmed in a recent meta-analysis [55], whereby the pooled relative effect size from ten included studies was 0.16 (+6%), suggesting that caffeine ingestion enhances isokinetic strength. However, again, this effect was not observed in smaller muscle groups such as the elbow flexors and was predominately manifested in the knee extensors.…”

Acute Caffeine Intake Enhances Mean Power Output and Bar Velocity during the Bench Press Throw in Athletes Habituated to Caffeine

“…Acute CAF intake causes a slightly different response to upper and lower body exercise [10], despite the lack of a mechanisms explaining this phenomenon. A recent meta-analysis about the effects of CAF on muscle strength and power output found that CAF significantly improved upper but not lower body 2 of 13 strength [7].…”

“…Current research recommends doses of CAF ranging from 3 to 6 mg/kg body mass to elicit ergogenic benefits, while the time of ingestion (from 30 to 90 min before exercise) and the form of ingestion (pills, liquid, chewing gum) are less significant as CAF is rapidly absorbed after ingestion [6]. However, the optimal protocol of CAF supplementation may differ based on the type and duration of exercise, previous habituation to CAF and the type of muscle contraction [6][7][8][9][10].…”