In last years it has been demonstrated that photobiomodulation therapy (PBMT) has ergogenic effects. However some key aspects, such as the potentially beneficial effects of PBMT during the detraining period still remain unknown. Therefore, the aim of this project is to evaluate the effects of PBMT applied before and after aerobic training sessions and during the detraining period.
It will be carried out a randomized, triple-blind, placebo-controlled trial. Seventy-two volunteers will be randomly allocated to four experimental groups: 1. PBMT before and after the aerobic training sessions and PBMT during the detraining period; 2. PBMT before and after the aerobic training sessions and placebo during the detraining period; 3. Placebo before and after the aerobic training sessions and PBMT during the detraining period; 4. Placebo before and after the aerobic training sessions and placebo during the detraining period . The individuals randomly allocated to the different groups will be subjected to 12 consecutive weeks of aerobic training performed on a treadmill 3 times a week on non-consecutive days. Each training session will last 30 minutes, with an intensity ranging from 85 to 90% maximum heart rate. PBMT or placebo will be applied before and after each training session. After the 12-week training period, the volunteers will receive the application of PBMT or placebo depending on the group to which they are allocated for 4 weeks (3 times a week) without training. The data will be collected by a blind assessor. It will be analyzed time of the exercise (time until exhaustion), maximum oxygen consumption in absolute and relative values in relation to body mass (VO2max). Moreover, it will be evaluated the body composition. The evaluations will be performed before starting the protocol (baseline) and after 4, 8, and 12 weeks of training. They will also be performed after 4 weeks without training (detraining period). The findings will be tested for their normality using the Shapiro-Wilk test. Parametric data will be expressed as mean and standard deviation and nonparametric data as median and respective upper and lower limits. Parametric data will be analyzed by two-way repeated measures analysis of variance (ANOVA; time versus experimental group) with post-hoc Bonferroni correction. Non-parametric data will be analyzed using the Friedman test and, secondarily, the Wilcoxon signed-rank test. Data will be analyzed in terms of both their absolute values and their relationship to the percentage change based on the values established in the baseline tests. The significance level will be set at p\<0.05.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
QUADRUPLE
Enrollment
60
PBMT will be applied bilaterally using the direct contact method with light pressure on the skin at different sites, namely 9 sites on the knee extensor muscles, 6 sites on the knee flexor muscles, and 2 sites on the plantar flexor muscles. A 12-diode cluster, with 4 905-nm laser diodes (12.5W peak power for each diode), 4 875-nm LED diodes (17.5 mW mean power for each diode), and 4 640-nm LED diodes (15 mW mean power for each diode), manufactured by Multi Radiance Medical® (Solon, OH, USA), will be used to apply the PBMT. The dose used for the applications during the training and/or detraining periods will be 30 Joules (J) per site (510 J per lower limb). PBMT will be applied before and after each training session and during the detraining period, depending on the group to which the volunteers are allocated.
Placebo will be applied bilaterally using the direct contact method with light pressure on the skin at different sites, namely 9 sites on the knee extensor muscles, 6 sites on the knee flexor muscles, and 2 sites on the plantar flexor muscles. The placebo PBMT will per performed using the dose of 0 J per diode. The sounds and signals emitted from the device as well as the information displayed on the screen will be identical, regardless of the type of treatment (active or placebo). Placebo will be applied before and after each training session and during the detraining period, depending on the group to which the volunteers are allocated.
Laboratory of Phototherapy and Innovative Technologies in Health
São Paulo, São Paulo, Brazil
Time until exhaustion.
The time until exhaustion will be measured by the software of ergospirometry system.
Time frame: 16 weeks - 4 weeks after completing the training (detraining period).
Time until exhaustion.
The time until exhaustion will be measured by the software of ergospirometry system.
Time frame: 4, 8, and 12 weeks after starting the training period.
Maximum oxygen consumption (VO2).
The rates of maximum oxygen consumption will be measured by an ergospirometry test.
Time frame: 4, 8, and 12 weeks after starting the training period, and at 4 weeks after completing the training (detraining period).
Fat percentage.
Fat percentage will be measured by diameters, perimeters, and skinfolds.
Time frame: 4, 8, and 12 weeks after starting the training period, and at 4 weeks after completing the training (detraining period).
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