Creatine supplementation and VO₂max: a systematic review and meta-analysis

Abstract

Although creatine supplementation is well-known to increase exercise performance in acute high-intensity exercises, its role in aerobic performance based on VO₂max is more controversial. Thus, we performed a systematic review and meta-analysis on the effects of creatine supplementation on VO₂max. PubMed, Cochrane, Embase, and ScienceDirect were searched for randomized controlled trials (RCTs) reporting VO₂max in creatine supplementation and placebo groups before and after supplementation. We computed a random-effects meta-analysis on VO₂max at baseline, within groups following supplementation, on changes on VO₂max between groups, and after supplementation between groups. Sensitivity analyses and meta-regression were conducted. We included 19 RCTs for a total of 424 individuals (mean age 30 years old, 82% men). VO₂max did not differ at baseline between groups (creatine and placebo). Participants in both groups were engaged in exercise interventions in most studies (80%). Using changes in VO₂max, VO₂max increased in both groups but increased less after creatine supplementation than placebo (effect size [ES] = −0.32, 95%CI = −0.51 to −0.12, p = 0.002). Comparisons after creatine supplementation confirmed a lower VO₂max in the creatine group compared to the placebo group (ES= −0.20, 95%CI = −0.39 to −0.001, p = 0.049). Meta-analysis after exclusion from meta-funnel resulted in similar outcomes in a subgroup of young and healthy participants. Meta-regressions on characteristics of supplementation, physical training, or sociodemographic were not statistically significant. Creatine supplementation has a negative effect on VO₂max, regardless of the characteristics of training, supplementation, or population characteristics.

Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.2008864 .

Keywords:

• Dietary supplement
• endurance
• cardiorespiratory fitness
• VO₂peak
• ventilatory threshold

Acknowledgements

The authors received no specific funding for this work.

Conclusion and practical implications

Our analysis showed the negative effects of CS on VO₂max, regardless of the supplementation protocols, physical training, and population characteristics. Considering that creatine is the most widely used dietary supplement in sport, particular attention toward its use should be paid to endurance athletes.

Author contributions

Conceived and designed the study: FD and JBBM. Conducted the systematic literature search: DG, CL. Final approval of eligible articles: all authors. Analyzed the data: DG, FD and BP. Wrote the first draft of the article: DG, FD, UU. Critical revision of the article: all authors. Integrity of the data analysis: DG, FD.

Disclosure statement

The authors declare no conflict of interest.

Data availability statement

All relevant data are within the paper.

Additional information

Funding

This work received no specific external funding.