Comparison between cryotherapy and photobiomodulation in muscle recovery: a systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 34669081 · doi:10.1007/s10103-021-03442-7
What was done
A systematic review and meta-analysis of randomized clinical trials was conducted across PubMed, PEDro, CENTRAL, and VHL up to June 2021. The review included studies of healthy adult volunteers undergoing isolated post-exercise photobiomodulation therapy (PBMT) versus cryotherapy (CRT). Meta-analyses calculated standardized mean differences (SMD) or mean differences (MD) with 95% confidence intervals, assessing risk of bias via Cochrane tools and certainty of evidence via GRADE.
What was found
Four randomized trials comprising 66 participants met inclusion criteria. Compared to cryotherapy, PBMT significantly improved muscle strength recovery (SMD = 1.73, 95% CI: 1.33 to 2.13, I² = 27%, p < 0.00001), reduced delayed onset muscle soreness (MD = -25.69%, 95% CI: -34.42% to -16.97%, I² = 89%, p < 0.00001), and lowered concentrations of muscle damage biomarkers (SMD = -1.48, 95% CI: -1.93 to -1.03, I² = 76%, p < 0.00001). No significant differences were observed between therapies for oxidative stress or inflammatory markers.
Why it matters
This review directly contrasts two widely used post-exercise recovery modalities, indicating that photobiomodulation may provide better functional and physiological recovery than traditional cryotherapy.
Limits
The total sample size was very small (4 studies, 66 participants total). GRADE certainty was rated moderate to very low, risk of bias in included trials ranged from low to high, and significant statistical heterogeneity was present for soreness (I² = 89%) and damage markers (I² = 76%).