Maximal oxygen uptake and exercise tolerance are improved in rats with heart failure subjected to low-level laser therapy associated with resistance training.

Abstract

Exercise tolerance and maximal oxygen uptake (VO2max) are reduced in heart failure (HF). The influence of combined resistance training (RT) and low-level laser therapy (LLLT) on exercise tolerance and VO2max in HF has not yet been explored. The aim of this study was to evaluate the influence of combined RT and LLLT on VO2max and exercise tolerance in rats with HF induced by myocardial infarction (MI). Rats were allocated to sedentary sham (Sed-Sham, n = 12), sedentary heart failure (Sed-HF, n = 9), RT heart failure (RT-HF, n = 7) and RT associated with LLLT heart failure (RT + LLLT-HF, n = 7) groups. After MI or sham surgery, rats underwent a RT and LLLT protocol (applied immediately after RT) for 8weeks. VO2max and exercise tolerance were evaluated at the end of protocol. HF rats subjected to LLLT combined with RT showed higher VO2basal (41%), VO2max (40%), VO2reserve (39%), run distance (46%), time to exhaustion (30%) and maximal velocity (22%) compared with HF rats that underwent RT alone. LLLT associated with RT improved oxygen uptake and exercise tolerance compared with RT alone in HF rats.