Photobiomodulation therapy (PBMT) has recently been used to alleviate postexercise muscle fatigue and enhance muscle recovery, demonstrating positive results. A previous study by the investigator's research group demonstrated the optimal dose and the optimal output power (100 mW) for an infrared wavelength (810 nm). However, the effects of optimized PBMT on performance and post-exercise recovery in high-level soccer players, to date have not been evaluated. The present research project aims to evaluate the effects of PBMT (using low-level laser therapy) applied before a progressive running test on functional, muscle damage, inflammatory and oxidative stress markers in high-level soccer players.
To achieve the proposed objective it will perform a randomized, crossover triple-blinded, placebo-controlled trial, with high-level soccer players as volunteers. Twenty-two volunteers will be randomly allocated to two intervention groups: active or placebo PBMT before a progressive running test (ergospirometry test). The blood samples for biochemical analysis will be obtained before and after a progressive running test, and another outcomes (functional) will be obtained during the test. The data will be collected by a blind assessor. The statistical analysis will follow the intention-to-treat principles and data on functional analysis will be analyzed using the paired and two-tailed t-student test. Data on biochemical analysis will be analyzed using two-way ANOVA, followed by Bonferroni post hoc test. The investigators will analyze: functional aspects (rates of oxygen uptake -VO2max (absolute and relative), aerobic and anaerobic threshold and time until exhaustion), muscle damage (creatine-kinase -CK and lactate dehydrogenase -LDH), inflammatory markers (IL-1β, IL-6 and TNF-α) and oxidative stress markers (Thiobarbituric acid -TBARS, catalase - CAT, superoxidedismutase - SOD and carbonylated proteins).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
22
The PBMT will be performed using the dose of 10J per diode, previously determined by a previous study and power output of 100 mW per diode, also previously determined. PBMT will be performed at nine different sites of the knee extensor muscles, six different sites of the knee flexor muscles and two different sites of the plantar flex muscles. As the cluster will be 5 diodes and 17 different sites will be irradiated, a total of 85 points will be irradiated in each lower limb, a total of 850 J of energy. The active PBMT will be performed before a progressive running test.
The placebo PBMT will per performed using the dose of 0 J per diode. Placebo PBMT will be performed at nine different sites of the knee extensor muscles, six different sites of the knee flexor muscles and two different sites of the plantar flex muscles. As the cluster will be 5 diodes and 17 different sites will be irradiated, a total of 85 points will be irradiated in each lower limb, a total of 0 J of energy. To ensure blinding, the device emitted the same sound regardless of the programmed mode (active or placebo PBMT). The placebo PBMT will be performed before a progressive running test.
Laboratory of Phototherapy and Innovative Technologies in Health
São Paulo, Brazil
Rates of oxygen uptake (VO2max).
The rates of oxygen uptake will be measured by an ergospirometry test.
Time frame: Immediately after (1 minute) of ergospirometry test. Observation: the rates of oxygen uptake (relative and absolute) will be measured during the progressive running test.
Aerobic threshold.
The aerobic threshold will be measured by an ergospirometry test.
Time frame: Immediately after (1 minute) of ergospirometry test. Observation: the aerobic threshold will be measured during the progressive runThe aerobic and anaerobic threshold will be measured during the progressive running test.
Anaerobic threshold.
The anaerobic threshold will be measured by an ergospirometry test.
Time frame: Immediately after (1 minute) of ergospirometry test (progressive running test). Observation: the aerobic threshold will be measured during the progressive running test.
Activity of creatine kinase - CK.
Muscle damage will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Activity of lactate dehydrogenase - LDH.
Muscle damage will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Levels of interleukin 1 beta - IL-1b.
Inflammation will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Levels of interleukin 6 - IL-6.
Inflammation will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Levels of tumor necrosis factor alpha - TNF-a.
Inflammation will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Levels of Thiobarbituric acid - TBARS
Oxidative stress will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Levels of carbonylated proteins.
Oxidative stress will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Activity of catalase - CAT.
Oxidative stress will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Activity of superoxidedismutase - SOD.
Oxidative stress will be measured by blood samples.
Time frame: The blood samples will be collected 5 minutes after the ergospirometry test (progressive running test).
Time until exhaustion.
The time until exhaustion will be measured by the software of ergospirometry system.
Time frame: Immediately after (1 minute) of ergospirometry test (progressive running test). Observation: the time until exhaustion will be measured during the progressive running test.
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