Effect of Light-Emitting Diode on the Strenght and Resistence Capacities of Cycling Athletes

Phototherapy is a therapeutic resource of increasing use in the last decade. The photobiomodulatory effects are commonly produced by means of low intensity lasers or LED emitting diodes, and can be used at different wavelengths. These light sources are divergent as to coherence, but produce equivalent tissue effects. The application of laser or LED light is able to induce biochemical changes in tissues, allowing for inhibitory or stimulating effects. These responses are associated to a cascade of cellular reactions, which favor the absorption of enzymes by cytochrome c oxidase, generating physiological responses that lead to decreased production of reactive oxygen species and increased synthesis of adenosine triphosphate (ATP). The application of this therapeutic resource brings ergogenic and protective benefits in muscular performance. The use of LED as a light source is promising because of its low cost, but there are no enough studies that support this use in athletes, with a focus on performance improvement. In addition to the deficiency of the sample, there is also no consensus regarding the use of different wavelengths for LED in the literature, thus opening gaps for the best protocol for the application of this technique. Therefore, a study that evaluates the use of LED in athletes, with different wavelengths, to improve performance is necessary. Hypothesis: It is hypothesized that the LED application is capable of improving athletes performance in terms of increased fatigue resistance, increased strength and power, increased muscle recruitment, and optimized oxygen demand. It is also expected that the results generated in this study can contribute to and increase the resources used by physiotherapists within the clinical-sports field, contributing to the post-training recovery, as well as the more effective physical performance in competitive activities.