Local and Systemic Effects of Photobiomodulation Therapy on Muscle Performance and Recovery Post-exercise.

• enzymatic activity of creatine kinase (CK)[ Time Frame: baseline ]
  wil be analysis of the enzymatic activity of CK as an indirect marker of muscle damage, the initial absorbance will be read through the spectrophotometry test, use of specific reagent kits commercial manufactured (Labtest®, São Paulo - Brazil). 5 ml Blood samples, via antecubital vein puncture, will be collected in tubes by a nurse. The samples, it will be centrifuged at 3000 rpm for 20 minutes. The supernatant (serum) will then be pipetted and stored in tubes (Eppendorf ®) at -80°C for further analysis of the enzymatic activity of creatine kinase (CK).
• enzymatic activity of creatine kinase (CK)[ Time Frame: 1 minute after the protocol of eccentric contractions ]
  wil be analysis of the enzymatic activity of CK as an indirect marker of muscle damage, the initial absorbance will be read through the spectrophotometry test, use of specific reagent kits commercial manufactured (Labtest®, São Paulo - Brazil). 5 ml Blood samples, via antecubital vein puncture, will be collected in tubes by a nurse. The samples, it will be centrifuged at 3000 rpm for 20 minutes. The supernatant (serum) will then be pipetted and stored in tubes (Eppendorf ®) at -80°C for further analysis of the enzymatic activity of creatine kinase (CK).
• enzymatic activity of creatine kinase (CK)[ Time Frame: 1 hour after the protocol of eccentric contractions ]
  wil be analysis of the enzymatic activity of CK as an indirect marker of muscle damage, the initial absorbance will be read through the spectrophotometry test, use of specific reagent kits commercial manufactured (Labtest®, São Paulo - Brazil). 5 ml Blood samples, via antecubital vein puncture, will be collected in tubes by a nurse. The samples, it will be centrifuged at 3000 rpm for 20 minutes. The supernatant (serum) will then be pipetted and stored in tubes (Eppendorf ®) at -80°C for further analysis of the enzymatic activity of creatine kinase (CK).
• enzymatic activity of creatine kinase (CK)[ Time Frame: 24 hours after the protocol of eccentric contractions ]
  wil be analysis of the enzymatic activity of CK as an indirect marker of muscle damage, the initial absorbance will be read through the spectrophotometry test, use of specific reagent kits commercial manufactured (Labtest®, São Paulo - Brazil). 5 ml Blood samples, via antecubital vein puncture, will be collected in tubes by a nurse. The samples, it will be centrifuged at 3000 rpm for 20 minutes. The supernatant (serum) will then be pipetted and stored in tubes (Eppendorf ®) at -80°C for further analysis of the enzymatic activity of creatine kinase (CK).
• enzymatic activity of creatine kinase (CK)[ Time Frame: 48 hours after the protocol of eccentric contractions ]
  wil be analysis of the enzymatic activity of CK as an indirect marker of muscle damage, the initial absorbance will be read through the spectrophotometry test, use of specific reagent kits commercial manufactured (Labtest®, São Paulo - Brazil). 5 ml Blood samples, via antecubital vein puncture, will be collected in tubes by a nurse. The samples, it will be centrifuged at 3000 rpm for 20 minutes. The supernatant (serum) will then be pipetted and stored in tubes (Eppendorf ®) at -80°C for further analysis of the enzymatic activity of creatine kinase (CK).
• enzymatic activity of creatine kinase (CK)[ Time Frame: 72 hours after the protocol of eccentric contractions ]
  wil be analysis of the enzymatic activity of CK as an indirect marker of muscle damage, the initial absorbance will be read through the spectrophotometry test, use of specific reagent kits commercial manufactured (Labtest®, São Paulo - Brazil). 5 ml Blood samples, via antecubital vein puncture, will be collected in tubes by a nurse. The samples, it will be centrifuged at 3000 rpm for 20 minutes. The supernatant (serum) will then be pipetted and stored in tubes (Eppendorf ®) at -80°C for further analysis of the enzymatic activity of creatine kinase (CK).
• Delayed onset muscle soreness (DOMS)[ Time Frame: baseline ]
  Delayed onset muscle soreness (DOMS) in the lower limb will be assessed using the Visual Analogue Pain Scale (VAS) using a 10 cm line, starting with the number 0, corresponding to no pain, and 10, corresponding to the worst possible pain. Volunteers will be instructed to mark the line where their pain best fits at that time. The evaluations will be performed prior to stretching and warm-up, 1 minute after the eccentric contractions protocol, and also 1, 24, 48, 72 hours after the protocol execution.
• Delayed onset muscle soreness (DOMS)[ Time Frame: 1 minute after the protocol of eccentric contractions ]
  Delayed onset muscle soreness (DOMS) in the lower limb will be assessed using the Visual Analogue Pain Scale (VAS) using a 10 cm line, starting with the number 0, corresponding to no pain, and 10, corresponding to the worst possible pain. Volunteers will be instructed to mark the line where their pain best fits at that time. The evaluations will be performed prior to stretching and warm-up, 1 minute after the eccentric contractions protocol, and also 1, 24, 48, 72 hours after the protocol execution.
• Delayed onset muscle soreness (DOMS)[ Time Frame: 1 hour after the protocol of eccentric contractions ]
  Delayed onset muscle soreness (DOMS) in the lower limb will be assessed using the Visual Analogue Pain Scale (VAS) using a 10 cm line, starting with the number 0, corresponding to no pain, and 10, corresponding to the worst possible pain. Volunteers will be instructed to mark the line where their pain best fits at that time. The evaluations will be performed prior to stretching and warm-up, 1 minute after the eccentric contractions protocol, and also 1, 24, 48, 72 hours after the protocol execution.
• Delayed onset muscle soreness (DOMS)[ Time Frame: 24 hours after the protocol of eccentric contractions ]
  Delayed onset muscle soreness (DOMS) in the lower limb will be assessed using the Visual Analogue Pain Scale (VAS) using a 10 cm line, starting with the number 0, corresponding to no pain, and 10, corresponding to the worst possible pain. Volunteers will be instructed to mark the line where their pain best fits at that time. The evaluations will be performed prior to stretching and warm-up, 1 minute after the eccentric contractions protocol, and also 1, 24, 48, 72 hours after the protocol execution.
• Delayed onset muscle soreness (DOMS)[ Time Frame: 48 hours after the protocol of eccentric contractions ]
  Delayed onset muscle soreness (DOMS) in the lower limb will be assessed using the Visual Analogue Pain Scale (VAS) using a 10 cm line, starting with the number 0, corresponding to no pain, and 10, corresponding to the worst possible pain. Volunteers will be instructed to mark the line where their pain best fits at that time. The evaluations will be performed prior to stretching and warm-up, 1 minute after the eccentric contractions protocol, and also 1, 24, 48, 72 hours after the protocol execution.
• Delayed onset muscle soreness (DOMS)[ Time Frame: 72 hours after the protocol of eccentric contractions ]
  Delayed onset muscle soreness (DOMS) in the lower limb will be assessed using the Visual Analogue Pain Scale (VAS) using a 10 cm line, starting with the number 0, corresponding to no pain, and 10, corresponding to the worst possible pain. Volunteers will be instructed to mark the line where their pain best fits at that time. The evaluations will be performed prior to stretching and warm-up, 1 minute after the eccentric contractions protocol, and also 1, 24, 48, 72 hours after the protocol execution.

Recent studies with photobiomodulation therapy have shown positive results in delaying skeletal muscle fatigue and improving performance through levels of biochemical markers and variables related to exercise when this therapy was applied before exercise. Some studies suggest that photobiomodulation therapy has systemic effects, but it is not known whether therapy exerts any systemic effects on human skeletal muscle. With this factor in mind, this research aims to verify the local and systemic effects of phototherapy on muscle performance and recovery after exercise in healthy male participants. This research consists in a randomized, triple-blinded, placebo-controlled trial, with participation of 30 healthy subjects. Will be analyzed parameters related to exercise performance (peak torque in the maximum voluntary contraction test- MVC), delayed onset muscle soreness (DOMS) by visual analogue scale (VAS), and biochemical marker of muscle damage (CK). The analysis will be performed before exercise protocol (baseline), after 1 minute of the exercise, and 1, 24, 48 and 72 hours after the end of exercise protocol

• Device: Phototherapy
  The Photobiomodulation Therapy will be applied 3 minutes after MVC test in 6 points of the quadriceps muscle (2 points in vastus lateralis, 2 in rectus femoris and 2 in vastus medialis).

• Placebo Comparator: Placebo-Control
  Photobiomodulation Therapy with the placebo program will be applied in both legs.
• Active Comparator: irradiation effect Local
  Photobiomodulation Therapy with the active irradiation will be applied on the exercised leg and Photobiomodulation Therapy with the placebo program will be applied on the non-exercised leg.
• Active Comparator: irradiation effect Systemic
  Photobiomodulation Therapy with the active program will be applied on non-exercised leg and Photobiomodulation Therapy with the placebo program will be applied on the exercised leg.