What the Research Says About Light and Muscle Recovery

Light therapy for sore muscles has been studied for longer than the skin applications, largely in sports science departments. The picture is more mixed than most marketing suggests, but it is not empty.

What the latest pooled analysis found

A systematic review and meta-analysis published in the Journal of Functional Morphology and Kinesiology in 2025 examined photomodulation therapy for delayed onset muscle soreness, the ache that arrives a day or two after hard training. Fourteen controlled studies met the inclusion criteria, using wavelengths between 660 and 950 nm applied to the affected muscles.

Pooling the studies that reported comparable data, soreness scores were significantly lower than placebo at 72 and 96 hours, a moderate effect. Muscle strength measurements showed a larger effect at 24 and 48 hours. The authors concluded that the therapy may help manage delayed onset muscle soreness, while noting that only four studies could be pooled quantitatively.

The honest caveats

• The studies are small, and protocols differ widely in wavelength, dose and timing.
• Most apply light to a specific muscle group, not the whole body.
• Timing varies. Some studies treat before exercise, others after.
• A moderate effect on a soreness scale is not the same as a performance guarantee.

How people use it in practice

The common pattern is a session on the muscles worked, on the same day as training, repeated through a hard block rather than used once after a bad session. As with skin, the published protocols are short and frequent rather than long and occasional.

If you already stretch, sleep and eat well and want one more lever, this is a reasonable one to try, with realistic expectations about the size of the effect.

Kivorla devices are general wellness devices, not medical devices. They are not a treatment for injury. If you are in pain, see a qualified healthcare professional.