Red Light Therapy for Stamina & Endurance: Scientific Evidence

A 2018 randomized trial tested 3 laser doses for their effect on oxygen uptake in cycling endurance. 20 male cyclists received 810 nm light at 200 mW, delivering 3, 6, or 9 J per diode, adding up to 135, 270, and 405 J per thigh, before time-to-exhaustion tests, 4 times per week across 5 days. The laser sped the rise in oxygen uptake and shrank the oxygen shortfall at the start of exercise as compared with placebo, in a dose-dependent way.

Doses of 15, 30, and 60 J per site were compared for their effect on running efficiency in a 2018 randomized controlled trial of 15 male recreational runners. LED photobiomodulation at 670, 850, 880, and 950 nm reached the front and back of the thigh and the calves in 64-second sessions. Running efficiency appeared to improve at set speeds under all 3 doses, most consistently at 30 J.

A 2018 triple-blinded trial tested whether the timing of photobiomodulation therapy (PBMT), given before treadmill training, after, both, or not at all, changed the results, and found that it did. 77 volunteers trained 3 times a week for 12 weeks and received PBMT before, after, both, or neither, with a cluster at 905, 875, and 640 nm delivering 30 J to each of 17 sites per leg. The group treated both before and after found that it raised how much oxygen the body used by about 18.7% and its time to exhaustion by about 13.4%, the strongest gain of any timing.

20 male competitive cyclists took part in a 2018 double-blind placebo-controlled crossover trial of low-level laser therapy (LLLT) for cycling endurance. 810 nm light at 200 mW reached both thighs at 135, 270, or 405 J per thigh before repeated time-to-exhaustion trials, 4 times per week across 4 days. All 3 doses appeared to lengthen time to exhaustion against placebo, pointing to better performance and less fatigue.

Across 297 participants pooled from 16 trials, a 2016 systematic review and meta-analysis weighed light therapy for exercise capacity and muscle performance. The studies applied laser or LED light before exercise to the biceps and front thigh, at 600 to 904 nm, 10 mW to 1.5 W, and 12 to 360 J. Laser therapy was associated with small gains in repetitions and time to exhaustion, which the review concluded as strong enough for practitioners to consider.

Distance covered and time to exhaustion both rose after a single light treatment in a 2016 crossover clinical trial of endurance in 20 untrained men. The active treatment combined super-pulsed lasers at 905 nm with LEDs at 875 and 640 nm, delivering 30 J to each of 17 sites per leg in a 3.8-minute session before a progressive treadmill test. Lung ventilation was also greater and breathlessness lower, pointing to broad gains in a single session.

With the help of a single elite runner, a 2015 randomized double-blind trial tracked how LED therapy changed oxygen uptake during high-intensity running. Near-infrared light at 830-870 nm and 50 mW reached the legs, arms, and trunk about 5 minutes before treadmill runs, across 3 sessions a week apart. After the real treatment, the runner's body took in oxygen faster than after the placebo, a sign his muscles were tiring less and using energy more efficiently. With a single athlete, the finding is only a starting point.

Peak oxygen use rose after laser light in a 2014 crossover trial built around a heart and lung fitness test. 18 healthy untrained adults, 9 men and 9 women averaging 22 years, received 850 nm low-level laser therapy at 100 mW and 2 to 14 J or placebo to the front thigh and calf muscles in a 20-second application, 2 times per week, 10 minutes before cycling tests. Adjusted for body weight, peak oxygen use was significantly higher after the laser than after placebo, pointing to better exercise capacity in untrained young adults.

Among postmenopausal women, a 2013 randomized trial tested whether infrared light during treadmill training could raise how much exercise the body can handle. 45 women were split into LED-plus-treadmill, treadmill-alone, and sedentary groups, and 30 completed 6 months of training, with 850 nm light at 100 mW reaching the thighs during 45-minute sessions twice weekly. Both training groups improved their aerobic fitness, and the light group appeared to gain more in exercise tolerance.

22 untrained men received 810 nm low-level laser therapy (LLLT) or placebo before progressive treadmill running in a 2012 crossover trial of endurance and cell damage from exercise. The active treatment delivered 200 mW and 30 J to several sites across both legs, 5 minutes before the run. The laser was associated with less exercise-induced cell damage and better running performance, and the researchers thought the two were connected.

20 elite female basketball players were split evenly, 10 to whole-body red light and 10 to no light, in a 2012 observational study of sleep and endurance. The treated group received 658 nm light for 30 minutes each night over 14 days, with sleep rated on a standard questionnaire and the sleep hormone melatonin measured in the blood. Sleep, melatonin, and endurance all improved in the light group, and the change in sleep tracked with the change in melatonin. According to the study, this offers a drug-free way to protect sleep after training.

Published in 2011, this clinical trial asked whether linear polarized near-infrared light (PL), paired with light warm-up, could improve muscle endurance. 10 people performed sustained grip work under different warm-up conditions while PL at 600-1400 nm reached the forearm muscles that bend the fingers. Force fell over time in every condition but appeared to hold up better when warm-up and light were combined, though the observational design makes the result only suggestive.

Researchers ran a 2024 randomized crossover pilot to see whether photobiomodulation helps amateur runners under both normal and low-oxygen conditions. 11 male runners aged 18 to 29 completed treadmill tests in normal oxygen and simulated altitude while receiving 850 nm light in 12-minute sessions. The therapy appeared partially effective, shifting some endurance and energy-use measures but not others, and as a pilot, it needs larger trials to confirm.

Pooling 37 trials and 586 participants, a 2022 meta-analysis tested photobiomodulation therapy (PBMT) across different exercise types. The studies treated a range of arm and leg muscles at 630 to 940 nm and 25 mW, sorted by single-joint actions, cycling, running, and swimming. PBMT improved endurance in single-joint work and time to exhaustion in cycling, but not strength, running, or swimming, so the benefit appeared to hinge on the exercise mode.

Comparing placebo against 3 rising doses, a 2024 double-blind crossover trial tested whether more light would help 5-km running in trained runners. 18 recreational runners averaging 28.7 years received placebo or 300, 900, or 1260 J of LED photobiomodulation at 620-780 and 780-1400 nm to the front and back of the thigh and the calves of both legs, 60 minutes before each run. None of the doses appeared to improve 5-km time or lower perceived effort, so the dose-response test found no benefit at any level.

Across 12 trials and 312 participants, a 2024 meta-analysis found no running-performance benefit from photobiomodulation. The pooled studies used 640 to 950 nm and doses from 300 to 3000 J, in sessions 1 to 3 times per week, measuring timed runs and time to exhaustion. Researchers reported that no significant effect appeared, whether the light was used alone or with training.

Whether light could help healthy adults with no symptoms was the question in a 2024 double-blind randomized trial of thigh strength and endurance. 28 people were split evenly between active and sham treatment, with laser and LED photobiomodulation at 585-620 and 780-1400 nm and 170 mW reaching the front thigh and calf muscles for 240 seconds per session, 4 times per week over 4 days. Neither maximum force nor endurance differed between the groups, and the trial concluded that the therapy did not help these outcomes.

No significant difference between light and placebo emerged in a 2019 randomized controlled trial of endurance running training in 30 untrained men. Over 8 weeks of training, photobiomodulation was applied before each session using 660 and 850 nm light at 10 and 30 mW, delivering 60 J to each of 5 points per leg in 30-second applications. 5-km performance and muscle soreness came out much the same in both groups, with only a possible small benefit that fell short of significance.

Published in 2018, this crossover trial tested LED therapy for oxygen uptake and heart output during moderate exercise transitions. 8 participants received 630 and 830 nm light to the leg muscles at 60 mW to 4.5 W in 40-second applications. The findings revealed that oxygen uptake, heart output, and blood by-product levels showed no differences between the light and placebo conditions.