Methods:

Seventy-five middle-aged men were sorted into the following four test groups: healthy, asymptomatic veteran athletes (ATH), their sedentary controls (SED), post-MI veteran athletes (ATH + MI), and post-MI sedentary controls (SED + MI). Veteran athletes had histories of lifelong (>20 years), regular, weekly, moderate (3-5.9 MET) to vigorous (6 MET) physical activity. All participants visited the laboratory on 2 separate days: day 1 included screening, physical exam, and incremental maximal cycling testing, and day 2 included blood samples for cardiovascular risk markers (glucose, lipids, and glycated hemoglobin) and thorough assessments of vascular structure and function by noninvasive echo-Doppler ultrasound techniques. Using the brachial artery, these techniques included endothelium-dependent flow mediated dilation (index of endothelial function), conduit artery vasodilatory capacity (index of arterial structure), and endothelium-independent dilation using glyceryl trinitrate (index of vascular smooth muscle function). Using the left carotid, right common femoral, and radial arteries, these techniques included measurements of pulse wave velocity (index of vascular stiffness) and conduit artery intima-media thickness.