Time Response of Photobiomodulation Therapy on Muscular Fatigue in Humans. Issue 11 (November 2018)

• Record Type: Journal Article
• Authors: Rossato, Mateus; Dellagrana, Rodolfo A.; Sakugawa, Raphael L.; Lazzari, Caetano D.; Baroni, Bruno M.; Diefenthaeler, Fernando
• Is Part Of: Journal of strength and conditioning research. Volume 32:Issue 11(2018)
• Publication Date: 2018-11
• Subjects: ergogenic -- low-level laser therapy -- light emitting diode therapy -- isokinetic tests; Physical education and training -- Periodicals; Weight training -- Physiological aspects -- Periodicals; Physical fitness -- Periodicals; 613.7
• DOI: 10.1519/JSC.0000000000002339
• Languages: English
• ISSNs: 1064-8011

Abstract

Abstract : Abstract: Rossato, M, Dellagrana, RA, Sakugawa, RL, Lazzari, CD, Baroni, BM, and Diefenthaeler, F. Time response of photobiomodulation therapy on muscular fatigue in humans. J Strength Cond Res 32(11): 3285–3293, 2018—The aim of this study was to identify the effects of 2 different time responses on fatigue of knee extensor. Sixteen male volunteers (26 ± 6.0 years, 81 ± 12 kg, and 181 ± 7.4 cm) participated in the study. Participants performed the same protocol in 5 sessions {control, placebo (placebo applied both 6 hours before and immediately before the test), 6 hours before + immediately before (photobiomodulation therapy [PBMT] applied both 6 hours before and immediately before the test), 6 hours before (PBMT applied 6 hours before and placebo applied immediately before the test), and immediately before (placebo applied 6 hours before and PBMT applied immediately before the test)}. Photobiomodulation therapy was applied on knee extensor (9 sites; 30 J per site). Maximal isometric voluntary contraction (MIVC) was assessed before and after an isokinetic fatigue (45 flexion-extension concentric at 180°·s −1 ), associated with electromyography (root mean square [RMS] and median of frequency [MF]). For MIVC, there was no treatment × time interaction for all variables. Time effect was observed for peak torque (PT), RMS, and MF. Treatment effect was verified for PT, and 6 hours before + immediately before condition presented higher PT during MIVCpre than control ( p = 0.004) and placebo ( p = 0.044). The immediately before presented higher PT values than control ( p = 0.047). Regarding MIVCpost, the PT for 6 hours before + immediately before presented higher values than control ( p = 0.001) and placebo ( p = 0.004). Peak torque during MIVC (pre to post) was reduced in 6 hours before + immediately before treatment (26%) compared with control (33%), placebo (29%), and immediately before (32%). The application of PBMT 6 hours + immediately before and immediately before exercise protocol is able to reduce the fatigue.