What is the best moment to apply phototherapy when associated to a strength training program? A randomized, double-blinded, placebo-controlled trial

Author(s)

Vanin, Adriane Aver ; Miranda, Eduardo Foschini ; Monteiro Machado, Caroline Santos ; Vicente de Paiva, Paulo Roberto ; Albuquerque-Pontes, Gianna Moes ; Casalechi, Heliodora Leao ; Camillo de Carvalho, Paulo de Tarso ; Pinto Leal-Junior, Ernesto Cesar

• Document type: Journal article
• Source: Lasers in Medical Science; v. 31, n. 8, p. 1555-1564, NOV 2016.
• Web of Science Citations: 23

Abstract

The effects of phototherapy (or photobiomodulation therapy) with low-level laser therapy (LLLT) and/or light-emitting diodes (LEDs) on human performance improvement have been widely studied. Few studies have examined its effect on muscular training and no studies have explored the necessary moment of phototherapy irradiations (i.e., before and/or after training sessions). The aim of this study was to determine the optimal moment to apply phototherapy irradiation when used in association with strength training. Forty-eight male volunteers (age between 18 to 35 years old) completed all procedures in this study. Volunteers performed the strength training protocol where either a phototherapy and/or placebo before and/or after each training session was performed using cluster probes with four laser diodes of 905 nm, four LEDs of 875 nm, and four LEDs of 640 nm-manufactured by Multi Radiance Medical (TM). The training protocol duration was 12 weeks with assessments of peak torque reached in maximum voluntary contraction test (MVC), load in 1-repetition maximum test (1-RM) and thigh circumference (perimetry) at larger cross-sectional area (CSA) at baseline, 4 weeks, 8 weeks, and 12 weeks. Volunteers from group treated with phototherapy before and placebo after training sessions showed significant (p < 0.05) changes in MVC and 1-RM tests for both exercises (leg extension and leg press) when compared to other groups. With an apparent lack of side effects and safety due to no thermal damage to the tissue, we conclude that the application of phototherapy yields enhanced strength gains when it is applied before exercise. The application may have additional beneficial value in post-injury rehabilitation where strength improvements are needed. (AU)

• FAPESP's process: 13/25814-0 - Acute adaptations of phototherapy associated to muscular training: Evaluation of different irradiation protocols
• Grantee: Caroline Monteiro Machado
• Support type: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 10/52404-0 - Low-level laser therapy in skeletal muscle fatigue and post-exercise recovery: Optimal parameters and effects in long-duration exercise
• Grantee: Ernesto Cesar Pinto Leal Junior
• Support type: Research Grants - Young Investigators Grants
• FAPESP's process: 13/19355-3 - Phototherapy associated to muscular training: Evaluation of different protocols of irradiation
• Grantee: Adriane Aver Vanin
• Support type: Scholarships in Brazil - Doctorate