Light-emitting diode therapy (photobiomodulation) effects on oxygen uptake and cardiac output dynamics during moderate exercise transitions: a randomized, crossover, double-blind, and placebo-controlled study

Author(s)

Beltrame, Thomas ^{[1, 2]} ; Ferraresi, Cleber ^{[3, 4, 5, 6, 7]} ; Parizotto, Nivaldo Antonio ^{[4, 5, 7]} ; Bagnato, Vanderlei Salvador ^[3] ; Hughson, Richard L. ^{[2, 8]}

Affiliation

^[1] Conselho Nacl Desenvolvimento Cient & Tecnol CNPq, Brasilia, DF - Brazil

^[2] Univ Waterloo, Fac Appl Hlth Sci, Waterloo, ON - Canada

^[3] Univ Sao Paulo, Phys Inst Sao Carlos, Opt Grp, Sao Carlos, SP - Brazil

^[4] Univ Fed Sao Carlos, Postgrad Program Biotechnol, Sao Paulo - Brazil

^[5] Univ Fed Sao Carlos, Dept Phys Therapy, Lab Electrothermophotherapy, Sao Paulo - Brazil

^[6] Univ Sagrado Coracao, Phys Therapy Dept, Postgrad Program Phys Therapy Funct Hlth, Sao Paulo - Brazil

^[7] Univ Brasil, Postgrad Program Biomed Engn, Sao Paulo - Brazil

^[8] Schlegel Univ Waterloo, Res Inst Aging, 250 Laurelwood Dr, Waterloo, ON N2J 0E2 - Canada

• Document type: Journal article
• Source: Lasers in Medical Science; v. 33, n. 5, p. 1065-1071, JUL 2018.
• Web of Science Citations: 1

Abstract

Light-emitting diodes (LEDs) might have a beneficial impact on cytochrome-c oxidase enzyme activity. Thus, it was hypothesized that photobiomodulation by light-emitting diode therapy (LEDT) could influence aerobic metabolism dynamics. Possible LEDT-mediated aerobic improvements were investigated mainly by a precise characterization of the pulmonary O (2) uptake dynamics during moderate exercise transitions. Eight healthy young adults were enrolled in this randomized, double-blind, placebo-controlled, crossover study. A multi-diode array of LEDs was used for muscular pre-conditioning 30 min and 6 h before exercise testing. Pulmonary O (2) uptake, carbon dioxide output, cardiac output, heart rate, stroke volume, and total arteriovenous oxygen difference dynamics were evaluated by frequency domain analysis. Comparisons revealed no statistical (p > 0.05) differences between LEDT and placebo, suggesting no significant changes in aerobic system dynamics. These results challenge earlier publications that reported changes in pulmonary O (2) uptake during incremental exercise until exhaustion after LEDT. Perhaps, increments in peak pulmonary O (2) uptake after LEDT may be a consequence of higher exercise tolerance caused by non-aerobic-related factors as opposed to an improved aerobic response. (AU)

• FAPESP's process: 10/07194-7 - Use of low-level laser and light-emitting diode therapy to increase muscle performance: from in vitro and experimental studies to clinical applications
• Grantee: Cleber Ferraresi
• Support Opportunities: Scholarships in Brazil - Doctorate