Long-Term Endurance and Power Training May Facilitate Motor Unit Size Expansion to Compensate for Declining Motor Unit Numbers in Older Age.

摘要: The evidence concerning the effects of exercise in older age on motor unit (MU) numbers, muscle fiber denervation and reinnervation cycles is inconclusive it remains unknown whether any are dependent type undertaken or localized to highly used muscles. MU characteristics vastus lateralis (VL) were assessed using surface intramuscular electromyography eighty-five participants, divided into sub groups based (young, old) athletic discipline (control, endurance, power). In a separate study biceps brachii (BB), same compared favored non-favored arms eleven masters tennis players. Muscle size was MRI ultrasound. VL, CSA greater young old, power athletes had largest within their groups. Motor potential (MUP) larger all old (p < 0.001), with interaction contrasts showing this age-related difference for endurance than controls, MUP controls. BB, thickness did not differ between = 0.575), but arm 0.001). Long-term training does prevent loss VL regardless discipline, may facilitate more successful axonal sprouting denervated fibers. These be muscles most involved exercise.