摘要： Apoptosis is a highly regulated form of cell death that is characterized by definite morphological, biochemical, and molecular events. Data indicate that acute exercise affects apoptotic signals in skeletal muscle and that the apoptotic response is strongly connected to strenuous exercise. This idea is supported by clinical and experimental studies showing that apoptosis occurs after the variety of exercise types as evidenced in running, swimming, and resistance exercise (RE). Although apoptosis induced by exercise may be a normal process used to remove partially damaged cells, it is possible that excessive exercise (e.g., high effort load) causes extensive cell death. Therefore, therapeutic interventions could be tested to attenuate this process in skeletal muscle. In this regard, photobiomodulation (PBM) may be suggested as a useful tool to counteract undesirable effects of exercise. This is based, for example, on studies showing that the application of low-level laser therapy (LLLT) before RE can delay fatigue and attenuate muscle necrosis, inflammation, and oxidative stress. Further evidence in favor of the PBM comes from an important study by Sussai et al., in which the application of LLLT immediately after swimming to exhaustion attenuated the number of apoptotic muscle cells. To our knowledge, only the study by Sussai et al. has examined the repercussion of LLLT on aerobic exercise–induced apoptosis and there is no information on whether a similar response could be obtained upon RE. Moreover, it is unclear how different doses of LLLT affect exercise-induced apoptosis. With this perspective in mind, we investigated whether LLLT, performed with three differences pre-exercise doses, would affect RE-induced muscle apoptosis in rats.