It is unknown whether commencing structured endurance training after 40 years of age is powerful enough to induce beneficial cardiovascular adaptations in later life. 34 men between the ages of 55 and 75 were included: 10 life-long sedentary seniors (SED), 13 endurance master athletes who commenced training≤30 years of age (ET30), and 11 endurance master athletes who commenced training≥40 years of age with no prior physical training (ET40). All performed resting 5-min spectral heart rate (HR) variability analysis, resting and submaximal-exercise echocardiography, and a maximal exercise test. Maximal oxygen uptake was higher and resting HR was lower in both trained groups vs. SED, without difference between ET30 and ET40. Atrial and left ventricle dimensions were greater in ET30 and ET40 vs. SED, without difference between both athletes groups. At rest, total arterial compliance was improved in both ET30 and ET40 compared to SED. During submaximal exercise, improvement in global LV afterload was only observed in ET30 vs. SED. Two powerful markers of health, maximal oxygen uptake and resting HR, did not differ between athletes who commenced training before 30 or after 40 years of age, but were significantly improved compared to their life-long sedentary counterparts.