Acute paralytic poliomyelitis causes diffuse injury to the motor neuron pool. The clinical picture is determined by the extent of motor neuron loss; however, clinically unaffected segments may have suffered substantial viral injury. The individual that suffered acute paralytic poliomyelitis carries the burden of a depleted motor neuron pool and often a residual biomechanical deficit into aging. This interaction often results in late effects of new muscle weakness, prominent fatigue, and sometimes new muscle atrophy with aging, called the postpolio syndrome. Cardiovascular and conventional muscle strengthening exercises must be initiated with caution in the patient with postpolio syndrome. Previously injured and altered motor units may have chronic relative overuse. Training will further stress these units and may accelerate declining performance. The goal of exercise and muscle training should be carefully considered in the postpolio patient. Nonspecific muscle strengthening exercise is generally undesirable unless applied to clearly unaffected or only minimally affected muscle groups. Exercise for cardiovascular fitness is more desirable and carries less risk of exacerbating overuse if applied with caution. When exercise is initiated, it should be punctuated by rest periods, and the intensity must not exceed a level that produces pain or more than transient fatigue.