Maximal Muscle Strength Deteriorates with Age in Subjects with Type 2 Diabetes Mellitus

Background: It is difficult to improve muscle strength with only aerobic exercise training in type 2 diabetes patients. Resistance training is effective for improving muscle mass, muscle strength and insulin sensitivity. One repetition maxima (1RM), or the maximum amount of weight a subject can lift in a single repetition, may be a useful unit for evaluating the results of resistance training in type 2 diabetic patients. This study was aimed to assess baseline values for 1RM in a sample of Korean type 2 diabetes mellitus patients that are scaled for intensity and load of exercise, and to assess the relationship of 1RM to age. Methods: A total of 266 (male: 95, female: 171) Korean patients with type 2 diabetes mellitus were included in the study sample. Maximal muscle strength was assessed by measuring 1RM for each subject (KEISER, Fresno, CA, USA). Two different exercises were used to measure 1RM: the chest press for the upper extremities, and the leg press for the lower extremities. Results: Both upper and lower values of 1RM decreased with age in men and women; upper 1RM: r = -0.454, P < 0.001 in men, r = -0.480, P < 0.001 in women, lower 1RM: r = -0.569, P < 0.001 in men, and r = -0.452, P < 0.001 in women. Values of 1RM significantly decreased in men only after the age of 70. In women, values of 1RM continuously decreased after the age of 60. Conclusion: The maximal muscle strength of individuals with type 2 diabetes decreases with age. We believe that resistance training is especially beneficial for type 2 diabetes mellitus patients after the sixth decade of life. (Korean Diabetes J 33:412-420, 2009)