Endurance training effect on individuals with postpoliomyelitis.

OBJECTIVE To determine the effects of an endurance training program on the exercise capacity and muscle structure and function in individuals with postpolio syndrome. DESIGN Preexercise and postexercise testing was performed with muscle strength evaluations using isokinetic testing as well as hand-held Myometer. Muscle fatigue was determined by use of isokinetic testing, and endurance was determined by exercise testing. Enzymatic evaluation was performed with muscle biopsies taken at the same site; preexercise and postexercise muscle cross-sectional area was measured by computed tomography. Disability and psychosocial evaluation was performed by a Functional Status Questionnaire. SETTING A university. SUBJECTS Seventeen postpolio subjects ranging in age from 39 to 49 years volunteered for a 6-month combined endurance and strength training program. They had a history of acute poliomyelitis at least 25 years earlier and were able to walk with or without aid. INTERVENTION Twelve of the subjects (mean age 42 years) completed the program, attending an average of 29 sessions, which were offered for 60 minutes twice a week. MAIN OUTCOME MEASURES Strength, endurance, enzymatic activity, and cross-sectional area were measured 3 months before the beginning of training, just before training, and at the completion of the exercise program. RESULTS Knee extension was reduced to an average of 60% of control values and did not change with training. Strength measured with a hand-held Myometer increased significantly for elbow flexion, wrist extension, and hip abduction. Exercise test on a bicycle-ergometer showed significant reduction (6beats/min) in heart rate at 70W and increase (12beats/min) in maximal heart rate with training. The training program could be performed without major complications and resulted in an increase in muscle strength in some muscle groups and in work performance with respect to heart rate at submaximal work load.