Using Pre-Exercise Photobiomodulation Therapy Combining Super-Pulsed Lasers and Light-Emitting Diodes to Improve Performance in Progressive Cardiopulmonary Exercise Tests

J Athl Train. 2016 Feb;51(2):129-35. doi: 10.4085/1062-6050-51.3.10. Epub 2016 Mar 4.


Context: Skeletal muscle fatigue and exercise performance are novel areas of research and clinical application in the photobiomodulation field, and positive outcomes have been reported in several studies; however, the optimal measures have not been fully established.

Objective: To assess the acute effect of photobiomodulation therapy (PBMT) combining superpulsed lasers (low-level laser therapy) and light-emitting diodes (LEDs) on muscle performance during a progressive cardiopulmonary treadmill exercise test.

Design: Crossover study.

Setting: Laboratory.

Patients or other participants: Twenty untrained male volunteers (age = 26.0 ± 6.0 years, height = 175.0 ± 10.0 cm, mass = 74.8 ± 10.9 kg).

Intervention(s): Participants received PBMT with either combined superpulsed lasers and LED (active PBMT) or placebo at session 1 and the other treatment at session 2. All participants completed a cardiopulmonary test on a treadmill after each treatment. For active PBMT, we performed the irradiation at 17 sites on each lower limb (9 on the quadriceps, 6 on the hamstrings, and 2 on the gastrocnemius muscles), using a cluster with 12 diodes (four 905-nm superpulsed laser diodes with an average power of 0.3125 mW, peak power of 12.5 W for each diode, and frequency of 250 Hz; four 875-nm infrared LED diodes with an average power of 17.5 mW; and four 640-nm red LED diodes with an average power of 15 mW) and delivering a dose of 30 J per site.

Main outcome measure(s): Distance covered, time until exhaustion, pulmonary ventilation, and dyspnea score.

Results: The distance covered (1.96 ± 0.30 versus 1.84 ± 0.40 km, t19 = 2.119, P < .001) and time until exhaustion on the cardiopulmonary test (780.2 ± 91.0 versus 742.1 ± 94.0 seconds, t19 = 3.028, P < .001) was greater after active PBMT than after placebo. Pulmonary ventilation was greater (76.4 ± 21.9 versus 74.3 ± 19.8 L/min, t19 = 0.180, P = .004) and the score for dyspnea was lower (3.0 [interquartile range = 0.5-9.0] versus 4.0 [0.0-9.0], U = 184.000, P < .001) after active PBMT than after placebo.

Conclusions: The combination of lasers and LEDs increased the time, distance, and pulmonary ventilation and decreased the score of dyspnea during a cardiopulmonary test.

Keywords: fatigue; light-emitting diode therapy; low-level laser therapy; progressive-intensity exercise.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cross-Over Studies
  • Double-Blind Method
  • Exercise Test
  • Exercise Tolerance / physiology*
  • Humans
  • Lasers, Semiconductor*
  • Low-Level Light Therapy*
  • Male
  • Muscle Fatigue / physiology
  • Muscle Fatigue / radiation effects*
  • Muscle, Skeletal / physiology
  • Muscle, Skeletal / radiation effects*
  • Pulmonary Ventilation / physiology*
  • Young Adult