Physical exercise in type 1 diabetes: recommendations and care

Abstract

The management of type 1 diabetes mellitus (T1DM) is based on three pillars: insulin therapy, nutrition, and regular practice of physical activity. Physical exercises are associated with metabolic demands that depend on the individual's energy stores and level of physical conditioning, and vary according to environmental conditions and intensity, duration, and type of exercise. All these factors, added to eventual distress with competitions, exert influence on glucose metabolism. The athletic career of diabetic individuals is often hindered by a risk of hypoglycemia during and after the exercise, frequent hyperglycemia before, during, and after certain physical activities, occurrence of ketoacidosis, and presence of chronic microvascular and macrovascular complications. Aerobic exercises reduce the levels of blood glucose while anaerobic exercise may promote transient hyperglycemia. Although diabetic individuals may achieve excellence in sport, their physical performance should be maximized by strict blood glucose control, adequate modifications in insulin dose on the day of the exercise, and appropriate nutritional intake. This review discusses the impact of physical exercise on glucose metabolism, as well as nutritional considerations and strategies appropriate to the practice of physical exercises by patients with T1DM.

Maximal Fat Oxidation During Aerobic Exercise in Adolescents With Type 1 Diabetes

“…4,15 This recommendation is based on the evidence that regular exercise has an important role in the treatment of diabetes. 6,8,9 According to guidelines published by the International Society for Pediatric and Adolescent Diabetes, 16 individuals with diabetes practicing exercise must consider all the factors that influence its response, including the intensity, duration, and type of exercise, performance level, time and content of the meal consumed before the exercise, type of insulin administered and time of the last application.…”

“…3,4 In addition to all these benefits, physical exercise can also improve glycemic control in individuals with T1DM. 8,9,18 Although the practice of exercise is considered part of the treatment in patients with T1DM, the American College of Sports Medicine and American Diabetes Association emphasize the need for strategies to enable individuals with T1DM to participate safely in programs of physical activity with a reduced risk of hypoglycemia. 19 Young individuals with T1DM should choose the physical activity of their preference and practice it regularly if possible, maintaining consistency in terms of exercise extent and duration and time of the day when it is practiced, so that these individuals can enjoy the physical and psychosocial benefits that physical exercise promotes.…”

“…24 However, adipose tissue lipolysis increases the availability of fatty acids to the muscle, which according to evidence is an important determinant of fat oxidation rates during exercise. 8,23 Moreover, the contribution of fat to the energy expenditure during exercise is largely regulated by the intensity of the exercise, although several other factors are also involved, including the duration of the exercise, age, sex, degree of sexual maturation, diet, training, circulating insulin levels, and availability of energetic substrates. 24 Fat oxidation occurs at higher rates in children and adolescents, who may achieve VO 2 max values above 75% 25 .…”

“…3,7 Maximization of fat oxidation during exercise may bring health benefits, help control weight, and reduce the dependence of glucose as a source of energy. 8 Despite these advantages, the treatment of the patient with DM1 and reduction of hypoglycemia risks depend on the appropriate adjustment of healthy eating, insulin therapy and the intensity of physical activity. 8,9 The contribution of fat or carbohydrates as an energy source during exercise depends primarily on exercise intensity, but the disposal of glucose in individuals with type 1 diabetes mellitus (T1DM) may influence the choice of energetic substrate during exercise.…”

“…8 Despite these advantages, the treatment of the patient with DM1 and reduction of hypoglycemia risks depend on the appropriate adjustment of healthy eating, insulin therapy and the intensity of physical activity. 8,9 The contribution of fat or carbohydrates as an energy source during exercise depends primarily on exercise intensity, but the disposal of glucose in individuals with type 1 diabetes mellitus (T1DM) may influence the choice of energetic substrate during exercise. 7,9 There are limited studies evaluating the metabolism of fat during exercise in children and adolescents with T1DM.…”