S.L. is a 50-year-old woman with a body mass index of 30 kg/m2 and a 4-year history of type 2 diabetes. Her only medication is metformin, which she takes twice per day. She is a lawyer with a sedentary lifestyle. She admits that she also struggles to adequately monitor her diet. Her recent fingerstick blood glucose levels have ranged from 95 to 280 mg/dL, with the higher values taken after meals. At her recent medical checkup, her A1C was 8.7%, elevated from her previous measurement at 7.5%. Because current metformin monotherapy has failed to control her hyperglycemia, the physician discussed the risks of chronic hyperglycemia as well as options for achieving glycemic control. Following this discussion, S.L. expressed a renewed interest in making a stronger attempt at lifestyle management. The physician encouraged this new commitment. She recommended an outpatient rehabilitation clinic for development of an appropriate exercise program as well as consultation with a dietitican for dietary control. She also prescribed another antidiabetic agent, repaglinide, to decrease postprandial blood glucose elevations. For the past month, S.L. has been participating in an aerobic and resistance exercise program 5 times per week, as initially prescribed by a physical therapist. Today, she arrived at the clinic for a reevaluation and advancement of her exercise program. After assessment of baseline vital signs, the physical therapist started S.L. on the treadmill for an aerobic warm-up. Within 10 minutes, S.L. became diaphoretic and shaky. The therapist assisted her off the treadmill and into a chair. S.L. performed a fingerstick blood glucose reading, which was 53 mg/dL. The therapist brought her some fruit juice and hard candy. Within 30 minutes, S.L. felt well and a second fingerstick blood glucose reading was 92 mg/dL.
Across the world, 8.5% of adults have diabetes mellitus. In the United States, more than 30 million people have diabetes and approximately 84 million adults have prediabetes. Thus, over one-third of Americans are directly affected by this chronic disease or are on its path. Because the risk of developing type 2 diabetes increases with age, obesity, and lack of physical activity, its prevalence is expected to grow.
Physical therapists commonly treat individuals burdened by diabetic complications such as heart disease, end-stage renal disease, amputation, and blindness. Lifestyle management—diabetes self-management education, medical nutrition therapy, physical activity, smoking cessation counseling, and psychosocial care—is a fundamental cornerstone of diabetes prevention and diabetes care. The importance of regular exercise in glycemic control has been increasingly appreciated as the molecular mechanisms of glucose disposal have been elucidated. Muscle contractions move glucose transporters to the surface of muscle fibers, increasing glucose disposal within trained muscle fibers. In a simple analogy, trained muscles can be viewed like sponges that “soak up” glucose from the blood. If larger muscle groups are exercised, larger “sponges” are available to “soak up” excess blood glucose. Exercise not only improves blood glucose ...