Diabetes mellitus (DM) is a metabolic disorder, characterized by hyperglycemia and metabolic disorders, resulting in changes in insulin secretion and / or action. Physical function is critical for functional independence, and chronic diseases such as diabetes can lead to functional decline, and diabetes mellitus is a major contributor to the progression of sarcopenia and physical disability. DM is also known to have a strong associated with the development of peripheral arterial disease. Peripheral arterial disease is characterized by obstruction of the arteries of the lower limbs, leading to a low oxygenation of the muscles of the lower extremities. Among the physiotherapeutic resources that can be used, phototherapy involves the use of light for the treatment of muscular injuries, by modulating the physiological processes associated with the repair process. Clinical trials show that light emitting diode (LED) is a technique that interferes with muscle strength, generating an increase in maximal voluntary contraction and peak torque. It is hypothesized that the LED application is capable of improving the muscular strength, fatigue, functional performance and blood flow capabilities in individuals with diabetes. It is also expected that the results of this study may contribute to and increase the resources used by physiotherapists within the clinical scope, contributing to the care of diabetic patients.

Diabetes mellitus (DM) is a metabolic disorder, characterized by hyperglycemia and metabolic disorders, resulting in changes in insulin secretion and / or action. Physical function is critical for functional independence, and chronic diseases such as diabetes can lead to functional decline, and diabetes mellitus is a major contributor to the progression of sarcopenia and physical disability. DM is also known to have a strong associated with the development of peripheral arterial disease. Peripheral arterial disease is characterized by obstruction of the arteries of the lower limbs, leading to a low oxygenation of the muscles of the lower extremities. Among the physiotherapeutic resources that can be used, phototherapy involves the use of light for the treatment of muscular injuries, by modulating the physiological processes associated with the repair process. Clinical trials show that LED is a technique that interferes with muscle strength, generating an increase in maximal voluntary contraction and peak torque. It is hypothesized that the LED application is capable of improving the muscular strength, fatigue, functional performance and blood flow capabilities in individuals with diabetes. It is also expected that the results of this study may contribute to and increase the resources used by physiotherapists within the clinical scope, contributing to the care of diabetic patients. A randomized and blinded clinical trial will be carried out at the Physiotherapeutic Resources Laboratory (LARF) of the University of São Paulo Medical School of Ribeirão Preto (FMRP-USP). The study procedures will be performed in 5 days. On the first day (pre-treatment), the volunteers will be evaluated for functionality (Time Up and Go), cardiopulmonary capacity (6-minute walk test), evaluation of muscle function (isokinetic dynamometer), neuromuscular recruitment (electromyography) gastrocnemius and evaluation of blood flow (Doppler) of the tibial and popliteal arteries. On the second, third and fourth day volunteers of GLED-V, GLED-IV, GM e GP will return to the application of LED intervention according to the group in which they are allocated. On the fifth day (reevaluation) the volunteers will perform the same tests of the first day.

Inclusion Criteria:

• Sedentary and insufficiently active individuals with the the International Physical Activity Questionnaire (IPAQ) .
• Both sexes
• Age range of 45 to 70 years
• Diagnostic Scale for Diabetic Distal Polyneuropathy - Score 3 or more

Exclusion Criteria:

• Present musculoskeletal or neurological lesions that make it impossible to perform the functional and strength tests.
• Negative result for the tactile sensitivity test with the monofilament.