A COMPARISON OF VENTILATION COMPONENTS IN YOUNG AND ELDERLY MEN DURING EXERCISE

To elucidate the influence of age on ventilation components during exe rcise, we investigated the change in fractional contribution of abdome n or thorax during exercise in 12 elderly (71.9 +/- 5.3, mean +/- SD y ears) and 12 young (25.0 +/- 4.9 years) normal male subjects using res piratory-inductive plethysmography. At rest, abdominal/thoracic contri bution was not different between elderly and young. During exercise, a bdominal contribution to total ventilation ,uas 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 elder ly (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 exerc ise; 25.6 +/- 1.5 - 27.8 +/- 1.6 [/min]; p < .05). The breathing patte rn kr the elderly during exercise was partly simulated in the young by reducing thoracic compliance using chest strapping. This study demons trates the greater participation of diaphragmatic motion together with rapid shallow breathing during lower graded exercise in the elderly a s compared with the young. This ventilatory pattern during exercise ma y result from a stiffening of the thorax with advancing age.