A comparison of ventilation components in young and elderly men during exercise.

To elucidate the influence of age on ventilation components during exercise, we investigated the change in fractional contribution of abdomen or thorax during exercise in 12 elderly (71.9 +/- 5.3, mean +/- SD years) and 12 young (25.0 +/- 4.9 years) normal male subjects using respiratory-inductive plethysmography. At rest, abdominal/thoracic contribution was not different between elderly and young. During exercise, abdominal contribution to total ventilation was decreased in the young compared to that at rest (rest: 53.6 +/- 2.9% vs exercise: 50.4 +/- 1.9-48.9 +/- 1.8%; p < .01), but significantly increased in the elderly (rest: 53.9 +/- 1.8% vs exercise: 57.3 +/- 1.7-59.8 +/- 2.0%; p < .01). Only in the elderly, respiratory frequency was increased during exercise compared to that at rest (rest: 20.1 +/- 0.8 [/min] vs exercise; 25.6 +/- 1.5-27.8 +/- 1.6 [/min]; p < .05). The breathing pattern in the elderly during exercise was partly simulated in the young by reducing thoracic compliance using chest strapping. This study demonstrates the greater participation of diaphragmatic motion together with rapid shallow breathing during lower graded exercise in the elderly as compared with the young. This ventilatory pattern during exercise may result from a stiffening of the thorax with advancing age.