Vascular and metabolic response to cycle exercise in sedentary humans: effect of age.
Am J Physiol Heart Circ Physiol
; 284(4): H1251-9, 2003 Apr.
Article
en En
| MEDLINE
| ID: mdl-12595287
We measured leg blood flow (LBF), drew arterial-venous (A-V) blood samples, and calculated muscle O(2) consumption (VO(2)) during incremental cycle ergometry exercise [15, 30, and 99 W and maximal effort (maximal work rate, WR(max))] in nine sedentary young (20 +/- 1 yr) and nine sedentary old (70 +/- 2 yr) males. LBF was preserved in the old subjects at 15 and 30 W. However, at 99 W and at WR(max), leg vascular conductance was attenuated because of a reduced LBF (young: 4.1 +/- 0.2 l/min and old: 3.1 +/- 0.3 l/min) and an elevated mean arterial blood pressure (young: 112 +/- 3 mmHg and old: 132 +/- 3 mmHg) in the old subjects. Leg A-V O(2) difference changed little with increasing WR in the old group but was elevated compared with the young subjects. Muscle maximal VO(2) and cycle WR(max) were significantly lower in the old subjects (young: 0.8 +/- 0.05 l/min and 193 +/- 7 W; old: 0.5 +/- 0.03 l/min and 117 +/- 10 W). The submaximally unchanged and maximally reduced cardiac output associated with aging coupled with its potential maldistribution are candidates for the limited LBF during moderate to heavy exercise in older sedentary subjects.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Consumo de Oxígeno
/
Envejecimiento
/
Ejercicio Físico
/
Músculo Esquelético
/
Pierna
Límite:
Adult
/
Aged
/
Humans
/
Male
Idioma:
En
Revista:
Am J Physiol Heart Circ Physiol
Asunto de la revista:
CARDIOLOGIA
/
FISIOLOGIA
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos