Red Light Therapy for Delayed Onset Muscle Soreness (DOMS): Scientific Evidence

36 collegiate men were assigned to either light-load lengthening exercise or low-level laser therapy (LLLT) in a 2017 randomized controlled trial of protection against muscle damage in the elbow flexors. The laser arm received 808 nm light at 100 mW and 1 J, pulsed at 2000 Hz, before a maximal damaging bout. The researchers reported that soreness dropped similarly with both approaches, suggesting the laser and the light-load exercise offered comparable protection.

Whether light beats cold therapy for muscle recovery was the question in a 2016 double-blinded placebo-controlled trial. 50 healthy men averaging 25 years were split across 5 groups covering photobiomodulation therapy (PBMT), cryotherapy, the 2 combined in each order, and placebo, with 630-650 and 904-906 nm light at 1.25 mW to 12.5 W and 0.38 to 39.37 J applied to the front of the thigh for 5 minutes, 4 times per week over 3 days, after damaging knee exercise. PBMT appeared to lower pain from 1 to 96 hours against placebo, outperforming cryotherapy and the combinations.

A 2014 double-blinded trial compared 3 light doses, 10, 30, and 50 J, for muscle performance and recovery. 40 untrained men averaging 24 years received a single session of combined super-pulsed laser and LED light at 640, 670, 875, and 905 nm to 6 sites on the front of the thigh in sessions of 76 seconds to 6.35 minutes, just after a baseline strength test. The 30 J dose held up maximum strength best from just after exercise to 96 hours, while the 10 and 50 J doses helped less.

Comparing LED phototherapy against placebo after damaging exercise, a 2014 double-blinded trial tracked muscle recovery in the elbow flexors. 17 healthy young men, 8 in the LED group and 9 in the placebo group, received 630 nm light at 300 mW to the biceps in a 30-second application after 30 lengthening contractions, with muscle force and range of motion followed for 96 hours. The placebo group lost more strength than the light group, and the light group held onto more of how far the joint could move.

36 healthy men, 18 per group, received low-level laser therapy (LLLT) or placebo before damaging knee-extensor exercise in a 2010 randomized controlled trial of muscle-damage markers. 810 nm light at 200 mW delivering 30 to 180 J in a 30-second application reached the front of the thigh before 75 maximal lengthening contractions. The laser appeared to blunt the rise in blood markers of muscle damage and the drop in muscle force, pointing to a protective effect.

Pain from soreness fell significantly at 48 hours after light therapy in a 2006 double-blind controlled trial. 27 healthy adults aged 18 to 35 were split into 3 groups and given 5 daily sessions of 660 and 880 nm light over the biceps, delivering 8 J/cm² per session. Pain on a standard scale dropped in the treated group against both control and sham at the 48-hour mark, which the study read as a real benefit after unfamiliar exercise.

33 young adults averaging 21 years ran 40 sprints of 15 metres in a 2022 trial of light therapy for recovery from exercise-induced muscle damage. 16 received 650 and 850 nm light at 10 and 200 mW and 0.3 to 60 J in 30-second applications before daily testing, while 17 received a sham, with recovery tracked over 5 days. The findings said that soreness in the calf appeared lower with the light, though the therapy did not speed recovery from the explosive, short sprints.

Three commercial devices were set against placebo in a 2017 randomized controlled trial comparing low- and high-powered light for exercise recovery and soreness. 40 untrained men received a single 180 J dose to the front of the thigh from a low-powered pulsed, low-powered continuous, or high-powered continuous device in sessions of 20 seconds to 3.8 minutes, with wavelengths spanning 630 to 990 nm. The low-powered pulsed device held up maximum strength and cut soreness better than the others, while the high-powered continuous device showed no benefit and even raised a muscle-damage marker.

When researchers applied low-level laser therapy (LLLT) either before or after jump-based exercise, a 2016 randomized controlled trial tracked its effect on muscle-damage markers in the front thigh. 24 healthy men were split into pre-exercise and post-exercise groups, receiving 810 nm light at 200 mW, delivering 6 to 240 J per leg in 30-second applications. Both timings appeared to cut pain by up to 30% against the untreated leg and to reduce an ultrasound sign of muscle damage.

Across 317 participants pooled from trials, a 2016 systematic review and meta-analysis weighed light therapy for delayed onset muscle soreness (DOMS). The included studies used wavelengths from about 600 to 950 nm, 5 mW to 1 W, and 4 to 3181 J, in a single session before or after exercise. Pain on a standard scale showed no difference between light and placebo across the pooled trials, though a separate look at a muscle-damage marker suggested some benefit, making the result partial.

Pairing photobiomodulation with gentle stretching, a 2022 randomized controlled trial tested the combination for delayed onset muscle soreness (DOMS). 54 untrained people received 780-840 nm light at 400 mW for about 2 minutes to the front of the thigh, 3 times per week over 3 days, alone or with low-intensity stretching. Neither the light nor the stretching relieved soreness, and the combination actually raised pain sensitivity rather than easing it.

No gain in performance or soreness followed 808 nm laser treatment in a 2021 crossover trial in young women. 13 untrained women received active and placebo laser sessions on the biceps, delivering 28 J in 70-second sessions, across 2 visits a week apart. Performance to exhaustion, perceived effort, and delayed onset muscle soreness (DOMS) were all unchanged by the active treatment.

Aiming a laser at 2 acupuncture points on the arm rather than at the muscle, a 2019 randomized controlled trial tested laser acupuncture for delayed onset muscle soreness (DOMS). 40 healthy participants were split into laser acupuncture and placebo groups, with 830 nm light delivering 36 J to the 2 points in a 10-minute session before exercise. It was found that pain scores did not improve with the active treatment, and laser acupuncture appeared to offer no benefit for preventing soreness.

A pilot design pitted infrared light against a sham probe on opposite arms in a 2006 randomized controlled trial of experimentally induced muscle soreness. 32 volunteers aged 19 to 35 were split evenly, 16 to the light group and 16 to the sham group, with 950 nm LED light at 160 mW applied to 1 arm for 6 minutes, 4 times per week over 4 days, after soreness was induced, while pain, pressure tolerance, and muscle function were tracked. Despite trends favoring the light, no significant difference appeared between the treated and sham arms.

2001 brought a preliminary trial of low-intensity infrared therapy for experimentally induced muscle soreness. 24 healthy volunteers, 12 men and 12 women, were assigned under strict double-blind conditions to control, placebo, or treatment groups of 8, with 840 nm light at 250 mW pulsed at 1000 Hz applied for 5 minutes to where the biceps meets its tendon, 4 times per week over 4 days. Pain and tenderness differed from the untreated control, but the therapy showed no advantage over placebo, and the authors concluded it was ineffective for soreness.

No treatment benefit on soreness emerged in a 1999 double-blind trial of combined low-intensity laser and phototherapy (CLILT). 36 people, 18 men and 18 women, had soreness induced in the elbow flexors of the non-dominant arm by repeated lengthening contractions to exhaustion, then received 660-950 nm light at 534 mW, pulsed at 73 Hz, for 4 minutes per session over 11 days. Every measure changed over time from the exercise, but none differed between the treated and control groups, offering no support for the therapy's claimed effects.

Published in 1996, this double-blind trial found no benefit from combined phototherapy and low-intensity laser for delayed onset muscle soreness (DOMS). 60 male volunteers were split into 5 groups of 12, receiving 660-950 nm light pulsed at 2.5, 5, or 20 Hz for 12 minutes, 3 times per week across 2 days, over where the biceps meets its tendon, after soreness was induced by exercise. Tenderness, pain, and how far the joint could move all changed with the exercise itself, but the light made no difference between groups.