Does an endurance training program improve maximal oxygen uptake and cardiac output in previously sedentary middle-aged men?
An 8-10 week endurance training program in sedentary middle-aged men improves maximal oxygen uptake and cardiac output, driven by increases in stroke volume.
AbstractFifteen previously sedentary men (38–55 years old) participated in an endurance training program which consisted of running for 2–3 half-hours a week for 8–10 weeks. Maximal oxygen uptake increased in all subjects, mean increase from 2.68 to 3.06 l/min, i.e. 14 per cent. This increase was brought about by a 13 per cent increase in maximal cardiac output, from 18.7 to 21.1 l/min. Heart rate was 8–17 beats/min lower during submaximal exercise. The maximal heart rate decreased by 6 (from 182 to 176) beats/min. Thus stroke volume was increased 7–17 ml at submaximal and 17 ml (16 per cent) at maximal exercise. Heart volume determined from X-rays did not change. After the training, mean arterial blood pressure was on the average 5 mm Hg lower at a given submaximal oxygen uptake; no change was observed at maximal exercise.Key Words: A-a oxygen gradient during exercisearterial blood pressurearterial PCO2arterial pHarterial PO2a-v oxygen differenceheart ratemaximal cardiac outputstroke volume
Hartley et al. (1969) studied this question.