Training, Detraining, Retraining and Glycemic Control in Patients With Type 2 Diabetes

During the last decades, the positive effects of aerobic exercise in patients with type 2 diabetes have been well documented. Recently, resistance exercise has gained popularity in diabetic patients since several studies have indicated that this type of training is safe and induces favorable adaptations in physical fitness and metabolic profile. According to recent scientific evidence, a complete rehabilitation program for patients with type 2 diabetes should combine both strength and aerobic exercise; thus the American Diabetic Association in their latest guidelines recommends strength training as part of an exercise program at least two times a week.

On the contrary to the well documented effects of physical training, there is lack of data on the negative alterations of detraining in patients with type 2 diabetes. The partial or complete loss of training-induced adaptations as a consequence of training reduction or cessation is well-documented by several detraining studies in healthy subjects, older individuals and patients with coronary artery disease.

For example, the investigators know that even 6 days of physical inactivity reduces insulin action in well-trained runners which is attributed to the significant reduction in the muscle GLUT-4 level. Factors such as illness, injury, travel or vacation may interrupt the training process for longer periods, affecting the treatment in people with type 2 diabetes. For this population, it is important to quantify changes in physiological and metabolic parameters resulting from the cessation of exercise, since exercise training is a major therapeutic method.

To the best of our knowledge, there is no data concerning the loss of physiological adaptations which occurs after exercise cessation in patients with type 2 diabetes, which have previously trained for a long period of time. The current study evaluated the effects of three months of detraining after nine months of a combined strength and aerobic training program on glycemic control, body composition, peak oxygen consumption (VO2peak) and muscular strength in patients with type 2 diabetes. Further, the investigators examined the extent of the regained adaptations after the resumption of training for a period of nine months.