ORIGINAL ARTICLE Infrared LED irradiation applied during high-intensity treadmill training improves maximal exercise tolerance in postmenopausal women: a 6-month longitudinal study Fernanda Rossi Paolillo & Adalberto Vieira Corazza & Audrey Borghi-Silva & Nivaldo Antonio Parizotto & Cristina Kurachi & Vanderlei Salvador Bagnato Received: 22 September 2011 / Accepted: 6 February 2012 # Springer-Verlag London Ltd 2012 Abstract Reduced aerobic fitness is associated with an increased risk of cardiovascular diseases among the older population. The aim of this study was to investigate the effects of LED irradiation (850 nm) applied during treadmill training on the maximal exercise tolerance in postmeno- pausal women. At the beginning of the study, 45 postmen- opausal women were assigned randomly to three groups, and 30 women completed the entire 6 months of the study. The groups were: (1) the LED group (treadmill training associated with phototherapy, n 0 10), (2) the exercise group (treadmill training, n 0 10), and (3) the sedentary group (neither physical training nor phototherapy, n 0 10). The training was performed for 45 min twice a week for 6 months at intensities between 85% and 90% maximal heart rate (HR max ). The irradiation parameters were 39 mW/cm 2 , 45 min and 108 J/cm 2 . The cardiovascular parameters were measured at baseline and after 6 months. As expected, no significant differences were found in the sedentary group (p ≥ 0.05). The maximal time of tolerance (Tlim), metabolic equivalents (METs) and Bruce stage reached significantly higher values in the LED group and the exercise group (p <0.01). Furthermore, the HR, double product and Borg score at isotime were significantly lower in the LED group and in the exercise group (p <0.05). However, the time of recovery showed a significant decrease only in the LED group (p 0 0.003). Moreover, the differences between before and after training (delta values) for the Tlim, METs and HR at isotime were greater in the LED group than in the exercise group with a significant intergroup difference (p <0.05). Therefore, the infrared LED irradiation during treadmill F. R. Paolillo : C. Kurachi : V. S. Bagnato Optics Group, Instituto de Física de São Carlos (IFSC), University of São Paulo (USP), São Carlos, SP, Brazil C. Kurachi e-mail: cristina@ifsc.usp.br V. S. Bagnato e-mail: vander@ifsc.usp.br F. R. Paolillo : N. A. Parizotto : C. Kurachi : V. S. Bagnato Biotechnology Program, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil N. A. Parizotto e-mail: parizoto@ufscar.br A. V. Corazza Department of Morphology, Faculty of Dentistry of Piracicaba, State University of Campinas (UNICAMP), Piracicaba, SP, Brazil e-mail: avcorazza@gmail.com A. Borghi-Silva Cardiopulmonary Physiotherapy Laboratory, Department of Physical Therapy, Federal University of São Carlos (UFSCar, São Carlos, SP, Brazil e-mail: audrey@ufscar.br N. A. Parizotto Electrothermophototherapy Laboratory, Department of Physical Therapy, Federal University of São Carlos (UFSCar, São Carlos, SP, Brazil F. R. Paolillo (*) University of São Paulo (USP), Av. Trabalhador Sãocarlense, 400 – Centro, CEP 13560-970, São Carlos, SP, Brazil e-mail: fer.nanda.rp@hotmail.com Lasers Med Sci DOI 10.1007/s10103-012-1062-y