The exercise heart rate profile in master athletes compared to healthy controls

Endurance exercise protects the heart via effects on autonomic control of heart rate (HR); however, its effects on HR indices in healthy middle-aged men are unclear. This study compared HR profiles, including resting HR, increase in HR during exercise and HR recovery after exercise, in middle-aged athletes and controls. Fifty endurance-trained athletes and 50 controls (all male; mean age, 48·7 ± 5·8 years) performed an incremental symptom-limited exercise treadmill test. The electrocardiographic findings and HR profiles were evaluated. Maximal O2 uptake (52·6 ± 7·0 versus 34·8 ± 4·5 ml kg(-1)  min(-1) ; P<0·001) and the metabolic equivalent of task (15·4 ± 1·6 versus 12·2 ± 1·5; P<0·001) were significantly higher in athletes than in controls. Resting HR was significantly lower in athletes than in controls (62·8 ± 6·7 versus 74·0 ± 10·4 beats per minute (bpm), respectively; P<0·001). Athletes showed a greater increase in HR during exercise than controls (110·1 ± 11·0 versus 88·1 ± 15·4 bpm; P<0·001); however, there was no significant between-group difference in HR recovery at 1 min after cessation of exercise (22·9 ± 5·6 versus 21·3 ± 6·7 bpm; P = 0·20). Additionally, athletes showed a lower incidence of premature ventricular contractions (PVCs) during exercise (0·0% versus 24·0%; P<0·001). Healthy middle-aged men participating in regular endurance exercise showed more favourable exercise HR profiles and a lower incidence of PVCs during exercise than sedentary men. These results reflect the beneficial effect of endurance training on autonomic control of the heart.