DOMS, Delayed Onset Muscle Soreness, is one of the most concrete obstacles to training consistency. It appears 12 to 72 hours after intense effort, lasts 2 to 5 days, and limits the quality and frequency of subsequent sessions. In 2025, the Journal of Functional Morphology and Kinesiology (MDPI) published an in-depth analysis of the efficacy of therapeutic photobiomodulation (PBMT) on this specific phenomenon.
Understanding DOMS: what happens in the muscle
Contrary to popular belief, DOMS is not caused by lactic acid. It results from micro-lesions of muscle fibers, mainly during eccentric contractions (descending stairs, deceleration, the negative phase of an exercise). These micro-lesions trigger a local inflammatory response that is both necessary (it stimulates repair and adaptation) and uncomfortable.
Eccentric contractions cause micro-ruptures at the sarcomere level. The ensuing inflammatory cascade, prostaglandins, bradykinin, pro-inflammatory cytokines, sensitizes muscle nociceptors and produces the characteristic pain of DOMS. Local swelling also contributes to perceived stiffness.
How PBMT acts on DOMS
Photobiomodulation intervenes at several levels of this inflammatory cascade:
- Reduction of pro-inflammatory cytokines: red and near-infrared light inhibits the production of TNF-α and IL-1β, two key cytokines in the DOMS cascade.
- Stimulation of ATP production: the additional energy available accelerates cellular repair and clearance of metabolic waste.
- Local vasodilation: the vasomotor effect improves the supply of oxygen and nutrients to damaged areas while accelerating the elimination of inflammatory mediators.
- Inhibition of prostaglandins: a mechanism similar to non-steroidal anti-inflammatory drugs (NSAIDs), but without the gastrointestinal side effects associated with their prolonged use.
What the MDPI 2025 study adds
The MDPI 2025 analysis stands out for its specific focus on DOMS rather than recovery in general. It identifies the optimal treatment parameters: energy density (dose in J/cm²), session frequency, and timing of application relative to effort.
The results confirm that the efficacy of PBMT on DOMS is dose-dependent up to a certain threshold, beyond which higher doses do not produce additional effects. This biphasic-response phenomenon is well known in the PBMT literature and underscores the importance of a calibrated protocol.
Comparison with other recovery methods
The study positions PBMT in the context of other interventions commonly used against DOMS:
- Cryotherapy: effective on immediate pain, less documented effects on functional recovery at 48–72h.
- Massage: effective on subjective perception, but biological effects (CK, LDH markers) are less consistent.
- NSAIDs (ibuprofen, etc.): reduce pain but can partially inhibit muscle adaptation by blocking inflammatory pathways needed for remodeling.
- PBMT: reduces pain and preserves adaptation markers, without the side effects of long-term NSAID use.
Our post-effort recovery protocols incorporate PBMT within 1 to 2 hours after an intense session. A 15–20 minute session on the muscle groups involved is enough to trigger the documented anti-inflammatory effects. It can be combined with pressotherapy for complementary drainage.