REF-1769 · Qiu et al., 2026 · Sports Health, · Paper · PubMed

In volleyball and football players described as high-level, laser photobiomodulation did not significantly change maximal voluntary contraction force, was reported to increase repetitions (SMD 0.58, 95% CI −0.05 to 1.21, p = 0.04) and lowered creatine kinase (MD −45.37, −55.52 to −35.22), in a meta-analysis of 14 randomised trials; the abstract's intervals contradict its own p values for force and repetitions, and creatine kinase is a marker

Main caveat: The abstract's confidence intervals contradict its p values for force and repetitions.
limited evidenceMeasured on trained to highly trained athletesRead from the abstract only

Qiu and colleagues pooled randomised trials of photobiomodulation in volleyball and football players described as high-level, asking whether it improves muscle performance and whether the response differs between the two sports. They searched four databases to April 2025 and found 14 eligible trials.

Compared with the control condition (not named in the abstract; placebo presumed) the active laser did not significantly change maximal voluntary contraction force, increased the number of repetitions and lowered creatine kinase, by the abstract's account. Split by sport, repetitions rose significantly in volleyball players and creatine kinase fell significantly in footballers.

The authors conclude that the treatment can delay the onset of muscle fatigue and reduce creatine kinase in these athletes and that the response differs between the two sports.

Participants

14 randomised trials in high-level volleyball and/or football players; number of players, sex, age and competition level are not in the abstract.

Protocol

Search: Web of Science, Medline, Scopus and PubMed, to 10 April 2025.
Inclusion: trials explicitly described as randomised controlled trials of photobiomodulation in high-level volleyball or football players.
What was applied: the abstract calls the active condition "active laser"; device, wavelength, dose, body site, contact with the skin and timing relative to exercise (before, after or across a training period) are not in the abstract. Whether any trials used LEDs is not stated.
Comparison: placebo (inferred from "active laser"; the abstract does not name the control explicitly).
Outcomes: maximal voluntary contraction force (MVC), number of repetitions, creatine kinase (CK).
Analysis: mean differences and standardised mean differences from means and standard deviations; model, heterogeneity and risk of bias are not in the abstract.

Key Results

Outcome (active laser vs control, placebo presumed)Effect (95% CI)pAuthors' reading
Maximal voluntary contractionMD 19.67 (7.36 to 31.72), unit not given0.31no significant effect
Number of repetitionsSMD 0.58 (−0.05 to 1.21)0.04significant increase
Creatine kinaseMD −45.37 (−55.52 to −35.22), unit not given< 0.001significant decrease
The intervals and p values do not agree: the force interval excludes zero yet p = 0.31, and the repetitions interval includes zero yet p = 0.04. Either the intervals or the p values are misprinted; from the abstract it cannot be told which, so neither the force null nor the repetition gain can be taken at face value.
By sport: repetitions rose significantly in volleyball players and creatine kinase fell significantly in footballers; sport-level numbers are not in the abstract.

Practical Application

Laser treatment in volleyball and football players lowered creatine kinase, a marker of muscle damage, and may have increased repetitions to fatigue; the abstract's numbers for force and repetitions contradict themselves, so the only clean result is the marker. A lower creatine kinase does not show faster recovery of performance (PHYS-44).
The sport difference is weak evidence: repetitions in volleyball and creatine kinase in football were probably measured in different trials, so the split may reflect what each trial measured rather than the sport.
Inference, not tested here: nothing here speaks to cyclists, runners or triathletes, or to a red-light panel or bed; the trials tested an "active laser".
Under SYNTH-83: "small trials in team-sport players show lower creatine kinase; a performance benefit is not established".

Limitations

The abstract's confidence intervals contradict its p values for force and repetitions.
Units of the mean differences for force and creatine kinase are not given; number of players, heterogeneity, risk of bias, and the light's parameters and timing are not in the abstract.
14 trials in two sports, probably small and possibly from few research groups (not stated); the other photobiomodulation meta-analyses draw on the same small body of trials (the 2024 running meta-analysis REF-1767 Nascimento 2024, for example, includes a trial in high-level football players), so the reviews are not independent confirmations (our reading; overlap not stated).
Funding and conflicts of interest are not in the abstract. Written from the abstract and the PubMed record; full text not read.
How this entry was checked and changed
Why this level

a meta-analysis of randomised trials capped at B+ because risk of bias not read (abstract only), and one step lower because the abstract's confidence intervals contradict its p values for two of three outcomes and the third (creatine kinase) is a marker

Content correction 2026-11-11
2026-11-11: added from the abstract and the PubMed record; level B (meta-analysis, risk of bias not read; intervals contradict p values; creatine kinase a marker).