Premium
Low‐level laser therapy associated with high intensity resistance training on cardiac autonomic control of heart rate and skeletal muscle remodeling in wistar rats
Author(s) -
Paolillo Fernanda Rossi,
Arena Ross,
Dutra Daniela Bassi,
de Cassia Marqueti Durigan Rita,
de Araujo Heloisa Selistre,
de Souza Hugo Celso Dutra,
Parizotto Nivaldo Antonio,
Cipriano Gerson,
Chiappa Gaspar,
BorghiSilva Audrey
Publication year - 2014
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.22298
Subject(s) - low level laser therapy , medicine , heart rate , resistance training , heart rate variability , skeletal muscle , cardiology , laser therapy , endocrinology , blood pressure , laser , physics , optics
Background and Objective Phototherapy plus dynamic exercise can enhance physical performance and improve health. The aim of our study was to evaluate the effect of low‐level laser therapy (LLLT) associated with high intensity resistance training (HIT) on cardiac autonomic and muscle metabolic responses in rats. Study Design/Materials and Methods Forty Wistar rats were randomized into 4 groups: sedentary control (CG), HIT, LLLT and HIT + LLLT. HIT was performed 3 times/week for 8 weeks with loads attached to the tail of the animal. The load was gradually increased by 10% of body mass until reaching a maximal overload. For LLLT, irradiation parameters applied to the tibialis anterior (TA) muscle were as follows: infrared laser (780 nm), power of 15 mW for 10 seconds, leading to an irradiance of 37.5 mW/cm 2 , energy of 0.15 J per point and fluency of 3.8 J/cm 2 . Blood lactate (BL), matrix metalloproteinase gelatinase A (MMP −2 ) gene expression and heart rate variability (HRV) indices were performed. Results BL significantly increased after 8‐weeks for HIT, LLLT and HIT + LLLT groups. However, peak lactate when normalized by maximal load was significantly reduced for both HIT and HIT + LLLT groups ( P <0.05). MMP −2 in the active form was significantly increased after HIT, LLLT and HIT + LLLT compared tom the CG ( P <0.05). There was a significant reduction in low frequency [LF (ms 2 )] and increase in high frequency [HF (un)] and HF (ms 2 )] for the HIT, LLLT and HIT + LLLT groups compared with the CG ( P < 0.05). However, the LF/HF ratio was further reduced in the LLLT and HIT + LLLT groups compared to the CG and HIT group ( P < 0.05). Conclusion These results provide evidence for the positive benefits of LLLT and HIT with respect to enhanced muscle metabolic and cardiac autonomic function in Wistar rats. Lasers Surg. Med. 46:796–803, 2014. © 2014 Wiley Periodicals, Inc.