title: Phototherapy during treadmill training improves quadriceps performance in postmenopausal women.
abstract: OBJECTIVE
  To evaluate the effects of infrared-light-emitting diode (LED) during treadmill training on functional performance.
  
  
  METHODS
  Thirty postmenopausal women aged 50-60 years were randomly assigned to one of three groups and successfully completed the full study. The three groups were: (1) the LED group, which performed treadmill training associated with phototherapy (n = 10); (2) the exercise group, which carried out treadmill training only (n = 10); and (3) the sedentary group, which neither performed physical training nor underwent phototherapy (n = 10). Training was performed over a period of 6 months, twice a week for 45 min per session at 85-90% of maximal heart rate, which was obtained during progressive exercise testing. The irradiation parameters were 100 mW, 39 mW/cm(2) and 108 J/cm(2) for 45 min. Quadriceps performance was measured during isokinetic exercise testing at 60°/s and 300°/s.
  
  
  RESULTS
  Peak torque did not differ amongst the groups. However, the results showed significantly higher values of power and total work for the LED group (∆ = 21 ± 6 W and ∆ = 634 ± 156 J, p < 0.05) when compared to both the exercise group (∆ = 13 ± 10 W and = 410 ± 270 J) and the sedentary group (∆ = 10 ± 9 W and ∆ = 357 ± 327 J). Fatigue was also significantly lower in the LED group (∆ = -7 ± 4%, p < 0.05) compared to both the exercise group (∆ = 3 ± 8%) and the sedentary group (∆ = -2 ± 6%).
  
  
  CONCLUSIONS
  Infrared-LED during treadmill training may improve quadriceps power and reduce peripheral fatigue in postmenopausal women.
authors.affiliation: * Optics Group from Physics Institute of São Carlos, University of São Paulo , Brazil.
authors.forename: F R
authors.initials: FR
authors.lastname: Paolillo
authors.forename: A V
authors.initials: AV
authors.lastname: Corazza
authors.forename: A R
authors.initials: AR
authors.lastname: Paolillo
authors.forename: A
authors.initials: A
authors.lastname: Borghi-Silva
authors.forename: R
authors.initials: R
authors.lastname: Arena
authors.forename: C
authors.initials: C
authors.lastname: Kurachi
authors.forename: V S
authors.initials: VS
authors.lastname: Bagnato
mesh_terms: D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D007259:Infrared Rays; D008875:Middle Aged; D018763:Muscle Fatigue / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology; D064797:Physical Conditioning, Human / Q000379:methods* / Q000502:physiology*; D017698:Postmenopause / Q000502:physiology*; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000502:physiology*; D019415:Torque
keywords: INFRARED; MUSCLE PERFORMANCE; PHOTOTHERAPY; PHYSICAL TRAINING; POSTMENOPAUSE