Photobiomodulation Therapy in a Field Test With High-level Rugby Players
Condition: High-level Rugby Athletes; Performance; Recovery
Study type: Interventional

Summary: 
      Background/Aim: While growing evidence supports the use of photobiomodulation therapy (PBMT)
      for performance and recovery enhancement, there have only been laboratory-controlled studies.
      Therefore, the aim of this study was to analyze the effects of PBMT in performance and
      recovery of high-level rugby players during an anaerobic field test.

      Methods: It is a randomized, crossover, double-blinded, placebo-controlled trial. Twelve male
      high-level rugby athletes were recruited in this study. No intervention was performed before
      the Bangsbo Sprint Test (BST) at familiarization phase (week 1). At weeks 2 and 3,
      pre-exercise PBMT or placebo were randomly applied to each athlete. PBMT/placebo irradiation
      was performed at 17 sites of each lower limb, employing a cluster with 12 diodes (4 laser
      diodes of 905nm, 4 LED diodes of 875nm, and 4 LED diodes of 640nm, 30J per site -
      manufactured by Multi Radiance Medical™). Average time of sprints, best time of sprints, and
      fatigue index were obtained from BST. Blood lactate levels were assessed at baseline, and at
      3, 10, 30 and 60 minutes after BST. Athletes' perceived fatigue was also assessed through a
      questionnaire.
    

Detailed description: 
      All exercise tests were conducted in an enclosed soccer/rugby field. The three test phases,
      administered one week apart, were performed on the same day of the week (Tuesday) and time
      (1-5pm). The average temperature inside the building during the trials ranged from 26°C to
      28°C. At first stage (exercise test 1) all athletes performed the Bangsbo Sprint Test (BST)
      to familiarization with the procedure. No interventions or comparators were applied before
      this test. However, at the second and third stages (exercise tests 2 and 3, respectively)
      either a placebo or active PBMT was applied according to randomization. Blood samples were
      collected from the athlete's fingertips prior to stretching and warming-up (baseline), and at
      3, 10, 30 and 60 minutes after BST at each of the three study stages/phase (exercise tests).
      After blood sample collection (to establish baseline), a warm-up comprised of low-intensity
      activities such as dynamic stretches and low-intensity short running were performed by each
      athlete. Following the warm-up and cool down period, either the active or placebo comparator
      was applied to the athlete according to the randomization procedure for the second test. For
      the third test, the other comparator was utilized to complete the cross over design. A quick
      perception of fatigue survey was administered following each test.
    

Intervention name(s): Photobiomodulation therapy (Phototherapy)
Intervention type(s): Device
Intervention description(s): PBMT was applied employing MR4 Laser Therapy Systems manufactured by Multi Radiance Medical, Solon - OH, USA. The cluster emitter contains 12 diodes with four super-pulsed laser diodes (905 nm, 0.3125 mW average power, and 12.5 W peak power for each diode), four red LED diodes (640 nm, 15 mW average power for each diode), and four infrared LEDs diodes (875 nm, 17.5 mW average power for each diode). It was applied in direct contact with the skin to 9 sites on extensor muscles of the knee, 6 sites on knee flexors of the knee, and 2 sites on the calf of both lower limbs. To ensure blinding, the device emitted the same sounds and regardless of the programmed mode (active or placebo).
Other intervention name(s): Photobiomodulation therapy (PBMT)
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Health Services Research
Keywords: Low-level laser therapy; Light emitting diodes; Rugby; Field test; Photobiomodulation