Left ventricular function at peak all-out anaerobic exercise in older men.

Background: All-out anaerobic exercise may be dangerous for the older population, due to hypoxia and inappropriate blood pressure response.

Objectives: This study compared and evaluated left ventricular function at peak all-out anaerobic effort in 12 well-trained older (58 +/- 1 years) and 12 young men (22 +/- 1 years).

Methods: Subjects were studied by echocardiography at peak all-out anaerobic exercise, on a cycle ergometer.

Results: Seven older subjects experienced ECG abnormalities. Significant (p < 0.05) differences between the older group and the young group, respectively, were noted for: cardiac output (9.8 +/- 0.9 and 15.8 +/- 0.9 l.min(-1)), left ventricular end-systolic pressure-volume ratio (4.7 +/- 0.8 and 4.4 +/- 4.9), left ventricular end-diastolic volume (104.8 +/- 6.9 and 125.7 +/- 6.2 ml), ejection fraction (67.1 +/- 6.0 and 59.8 +/- 5.5%), left ventricular end-systolic pressure volume ratio (4.4 +/- 0.4 and 4.8 +/- 0.3 ratio), and total peripheral resistance (966.0 +/- 84.0 and 660 +/- 82.8 dyn.s(-1).cm(-5)).

Conclusions: Data suggest that during all-out anaerobic exercise, forces opposing ejection were not reduced enough to avoid left ventricular dysfunction and ECG abnormalities in the older subjects. This is attributed to functional changes with age in the myocardium and associated blood vessels, leading to impairment of left ventricular function and blunted inotropic and chronotropic responses to catecholamine. Therefore, an all-out anaerobic-type effort should not be given to an older subject due to the great hazardous potential.