Effect of phototherapy (low-level laser therapy and light-emitting diode therapy) on exercise performance and markers of exercise recovery: a systematic review with meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 24249354 · doi:10.1007/s10103-013-1465-4
What was done
Authors conducted a systematic review and meta-analysis of randomized controlled trials (PubMed/Medline, 2000–2012) investigating low-level laser therapy (LLLT) or narrow-band light-emitting diode therapy (LEDT) applied before, during, or after exercise. Study quality was evaluated using the 10-item PEDro scale (cutoff score ≥6/10). Primary outcomes included time to exhaustion, number of repetitions, and creatine kinase activity.
What was found
Of 16 RCTs identified, 13 had acceptable quality and 3 were excluded for poor quality. Pre-exercise phototherapy (evaluated in 12 trials) significantly increased time to exhaustion by 4.12 seconds (95% CI 1.21–7.02, p < 0.005) and repetitions by 5.47 (95% CI 2.35–8.59, p < 0.0006) versus placebo. High heterogeneity precluded meta-analysis of creatine kinase, though 13 of 16 qualitative comparisons showed positive effects. The most consistent outcomes occurred with red or infrared wavelengths, pre-exercise application, 50–200 mW power output, and 5–6 J/point doses.
Why it matters
This meta-analysis provides consolidated trial evidence that phototherapy applied before muscular exertion produces measurable, modest gains in short-term endurance and repetition capacity.
Limits
The literature search was limited to a single database (PubMed/Medline) up to 2012. Total participant count and participant demographics were not reported in the abstract. Substantial heterogeneity in study designs prevented quantitative meta-analysis for muscle damage biomarkers.