Local and Systemic Effects of Photobiomodulation Therapy on Muscle Performance and Recovery Post-exercise.
Condition: Phototherapy; Low-level Laser Therapy; Systemic
Study type: Interventional

Summary: 
      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) and blood Lactate (BL).
      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
    

Detailed description: 
      A total of 30 healthy male non-athletes, between 18-35 years, will be randomly divided into 3
      experimental groups, named "Placebo (Control)", "Local", "Systemic", according to the lower
      limb who will receive photobiomodulation therapy. Firstly, a blood collection will be
      performed by a nurse with sterile and disposable materials for posterior analysis of creatine
      kinase (CK) and Blood Lactate (BL). Delayed onset muscle soreness (DOMS) will be assessed
      with the Visual Analogue Scale (VAS) using a 10 cm line. Participants will be instructed to
      mark the line where their pain best fits at that time (0=no pain, 10=worst pain).Then, the
      maximum voluntary contraction test (MVC) will be performed, which will consist in performing
      3 times of 5-sec isometric contractions of the non-dominant knee extensors in the isokinetic
      dynamometer device. During the execution of the MVC, the participants will be verbally
      encouraged to exert the greatest force at that moment. Photobiomodulation therapy will be
      applied 2 minutes after the MVC test in six points of non-dominant anterior thigh muscle.
      After irradiation, participants will perform the protocol of eccentric contractions. This
      protocol will be performed to induce muscle fatigue by resisting the movement of knee flexion
      in 5 series of 15 repetitions with 30 seconds -intervals (eccentric contractions).
      Assessments (blood collection, VAS and MVC) will be performed before warm-up (baseline), 1
      minute after exercise protocol and 1, 24, 48 and 72 hours after eccentric exercise protocol.
    

Intervention name(s): Phototherapy
Intervention type(s): Device
Intervention description(s): 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).
Other intervention name(s): Photobiomodulation Therapy; Low-Level Laser Therapy
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Randomized, triple-blind and placebo-controlled
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: phototherapy; systemic effect; recovery; performance; photobiomodulation