The low-level laser therapy (LLLT) has been used in many inflammatory disorders. More recently the LLLT was associated with an improvement in the muscle strength and endurance. But, these effects were described only in health or athletic individuals. In this randomized and controlled clinical trails, the investigators will study the effects of LLLT on muscle strength of the patients with kidneys failure on long time hemodialysis treatment. Additionally, investigators will explore three different intensities up the muscle strength.

This study will be conducing in a large hospital that is reference in kidneys disorders treatments. 16 patients will be randomized for placebo, 4J, 6J, or 8J low-level laser therapy (LLLT). The maximal voluntary contraction (MVC) will be test by handgrip test before and after de LLLT. One-week interval between the LLLT will gave to reduce the influence between the treatments. Moreover the endurance test will be use to evaluate the muscle oxidation impact of the LLLT.

Inclusion Criteria:

• chronic kidney failure,
• long time hemodialysis treatment (>18 months)

Exclusion Criteria:

• any health disturbance that can reduces the handgrip test performance beyond to the produced by the chronic kidney failure.