Heart rate recovery (HRR) as a function of vagal reactivation, which is an independent risk predictor for cardiovascular disease and mortality, is strongly associated with metabolic syndrome. Middle-aged obese men classified on the basis of Adult Treatment Panel III criteria were investigated in this study. Postexercise HRR and the HRR decay constant following a symptom-limited bicycle exercise test were evaluated before and after a 12-week exercise training program. Although the peak HR remained unchanged, HR at anaerobic threshold significantly decreased for both groups after exercise training; HR at rest was significantly decreased in the metabolic syndrome group after training. HRR significantly improved in the metabolic syndrome group with no change for the non-metabolic syndrome group. HRR decay constant values showed significant improvement in the metabolic syndrome group after exercise training but not the non-metabolic syndrome group.
This study demonstrated that moderate-intensity physical training without caloric restrictions improves HRR in obese men with metabolic syndrome, possibly due to a reduction in the resting HR. Therefore, weight loss-induced exercise training would help in improving the resting HR, and the responsiveness of the autonomic nervous system in obese men with metabolic syndrome.