Format

Send to

Choose Destination
J Int Soc Sports Nutr. 2018 Mar 5;15:11. doi: 10.1186/s12970-018-0216-0. eCollection 2018.

Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis.

Author information

1
1Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia.
2
2Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC USA.
3
3Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC USA.
4
Faculty of Education, Department of Kinesiology, J.J. Strossmayer University, Osijek, Croatia.

Abstract

Background:

Caffeine is commonly used as an ergogenic aid. Literature about the effects of caffeine ingestion on muscle strength and power is equivocal. The aim of this systematic review and meta-analysis was to summarize results from individual studies on the effects of caffeine intake on muscle strength and power.

Methods:

A search through eight databases was performed to find studies on the effects of caffeine on: (i) maximal muscle strength measured using 1 repetition maximum tests; and (ii) muscle power assessed by tests of vertical jump. Meta-analyses of standardized mean differences (SMD) between placebo and caffeine trials from individual studies were conducted using the random effects model.

Results:

Ten studies on the strength outcome and ten studies on the power outcome met the inclusion criteria for the meta-analyses. Caffeine ingestion improved both strength (SMD = 0.20; 95% confidence interval [CI]: 0.03, 0.36; p = 0.023) and power (SMD = 0.17; 95% CI: 0.00, 0.34; p = 0.047). A subgroup analysis indicated that caffeine significantly improves upper (SMD = 0.21; 95% CI: 0.02, 0.39; p = 0.026) but not lower body strength (SMD = 0.15; 95% CI: -0.05, 0.34; p = 0.147).

Conclusion:

The meta-analyses showed significant ergogenic effects of caffeine ingestion on maximal muscle strength of upper body and muscle power. Future studies should more rigorously control the effectiveness of blinding. Due to the paucity of evidence, additional findings are needed in the female population and using different forms of caffeine, such as gum and gel.

KEYWORDS:

Data synthesis; Ergogenic aid; Performance; Power

PMID:
29527137
PMCID:
PMC5839013
DOI:
10.1186/s12970-018-0216-0
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for BioMed Central Icon for PubMed Central
Loading ...
Support Center