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.
Thomas BeltrameFlávio de Castro MagalhãesNivaldo Antonio ParizottoVanderlei Salvador BagnatoRichard L HughsonPublished in: Lasers in medical science (2018)
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 O2 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 O2 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 O2 uptake during incremental exercise until exhaustion after LEDT. Perhaps, increments in peak pulmonary O2 uptake after LEDT may be a consequence of higher exercise tolerance caused by non-aerobic-related factors as opposed to an improved aerobic response.
Keyphrases
- high intensity
- double blind
- placebo controlled
- light emitting
- resistance training
- clinical trial
- heart rate
- pulmonary hypertension
- phase iii
- phase ii
- young adults
- study protocol
- carbon dioxide
- phase ii study
- physical activity
- blood pressure
- single cell
- left ventricular
- open label
- randomized controlled trial
- wound healing
- atrial fibrillation
- high throughput
- stem cells
- high density
- mesenchymal stem cells