Qiu D. et al. - Photobiomodulation and Muscle Performance in Volleyball and Soccer Players: A Meta-Analysis

A meta-analysis of 14 randomized controlled trials reports that photobiomodulation increases the number of repetitions performed and lowers creatine kinase levels in elite volleyball and soccer players. However, maximum voluntary contraction strength is not improved.

What this study measured

The use of photobiomodulation as an adjunct to performance and recovery in elite athletes remains a topic of debate. The team led by Dayong Qiu at Nanjing Normal University sought to determine whether this approach improves skeletal muscle performance in ball sports, and whether the response differs between volleyball players and soccer players. Web of Science, Medline, Scopus, and PubMed were searched through April 10, 2025; only randomized controlled trials conducted on elite volleyball players or soccer players were eligible, totaling 14 studies. Three criteria were analyzed: maximum voluntary contraction, number of repetitions, and blood levels of creatine kinase, a marker of muscle damage. The abstract does not mention a PROSPERO registration, and the authors classify the overall level of evidence as 2.

Key Findings

The picture is nuanced: the benefits relate to endurance during repeated exertion and to markers of muscle damage, not to maximum strength, and the response varies by sport.

• Maximum voluntary contraction: no significant effect (mean difference 19.67; 95% CI 7.36 to 31.72; p = 0.31)
• Number of repetitions: significant increase (SMD 0.58; 95% CI -0.05 to 1.21; p = 0.04)
• Créatine kinase : diminution significative (différence moyenne -45,37 ; IC 95 % -55,52 à -35,22 ; p < 0,001)
• Volleyball players: a significant increase in the number of repetitions in this subgroup
• Soccer players: significant decrease in creatine kinase in this subgroup

How photobiomodulation works for this indication

The mechanism described remains a working hypothesis. Red and near-infrared light applied to muscle tissue is thought to be absorbed by mitochondrial cytochrome c oxidase, which would transiently increase ATP availability. Better management of exercise-induced oxidative stress and modulation of local inflammation could delay muscle fatigue, which would account for the increase in the number of repetitions rather than in peak strength. The decrease in creatine kinase would support this interpretation. These explanations were not tested in the studies analyzed.

Limits You Should Know

The number of studies is small: 14 studies across three criteria and two disciplines, resulting in very small subgroups. The confidence interval for the number of repetitions crosses the zero value (-0.05 to 1.21), yet the result is presented as significant, indicating a fragile estimate. Conversely, the confidence interval for maximum voluntary contraction does not include zero, even though the result is reported as nonsignificant: this inconsistency in the summary warrants consulting the full text before drawing any firm conclusions. The units for creatine kinase are not specified. Finally, the participants are elite athletes, which limits the applicability of these findings to amateur athletes.

What This Means in Practice

These data suggest that photobiomodulation is more of a recovery tool than a means of increasing strength: the expectation of a gain in maximum power is not supported by this analysis. The plausible benefit relates to the ability to perform consecutive exercises and the reduction in markers of muscle damage following a high-intensity training session. The abstract does not specify the wavelength, power, duration of application, or number of sessions.

Frequently Asked Questions

Does photobiomodulation improve muscle strength?

Not in this meta-analysis: the authors found no significant effect on maximum voluntary contraction strength. The observed benefits relate to the number of repetitions and the reduction in creatine kinase levels—that is, to resistance to fatigue and post-exercise recovery.

When should photobiomodulation be used in conjunction with a workout?

The abstract does not specify either the timing of administration or the light parameters used; therefore, no recommendations regarding timing can be drawn from it. Administration before or immediately after exercise is examined elsewhere, but this study does not provide a definitive answer.

What is creatine kinase, and why is it measured?

It is a muscle enzyme whose blood levels rise after intense exercise: it serves as an indirect marker of muscle damage. In this study, photobiomodulation was associated with a significant decrease in this marker, particularly among soccer players, suggesting less muscle damage, though this does not guarantee a faster return to peak performance.

Reference

Qiu D, He J, Li B, Ni P, Zhao Z, Lv R, Li F. The Effect of Photobiomodulation Therapy on Muscle Performance in Volleyball and Soccer Players: A Meta-Analysis of Randomized Controlled Trials. Sports Health, 2025. PMID 40995827. View the study on PubMed

This summary is provided for informational purposes only and does not constitute medical advice. Photobiomodulation is not a substitute for prescribed treatment. Consult a healthcare professional.