Background – Heart rate recovery (HRR) is an independent risk factor for cardiovascular disease and mortality and is inversely associated with insulin resistance and co-related metabolic risk markers.
Objective – The objective of this study was to determine the effects of weight loss on HRR and it’s association with traditional cardiovascular risk markers in overweight and obese men with components of the metabolic syndrome. Design – HRR (defined as the decrease in HR from peak HR to that measured 1 minute after a standardised graded treadmill test) and a range of well-established cardiovascular risk factors, were measured in 42 overweight and obese men (BMI: 33.8±0.6 kg⋅m2; age: 46.5±1.3 yrs) who had no symptoms of cardiovascular disease, but had components of the metabolic syndrome, before and after 12-weeks of weight loss.
Outcomes – The dietary intervention resulted in a 9% weight reduction (P<0.001). There were significant reductions in waist circumference, blood pressure, plasma triglycerides, total, LDL and HDL cholesterol, triglyceride:HDL ratio, CRP, plasma insulin, glucose and HOMA (P<0.05). Although peak heart rate remained unchanged, HRR at 1 minute improved from 33.4±1.4 to 37.0±1.2 bpm (P<0.001) after weight loss. There were no changes in either cardiorespiratory fitness (P=0.30) nor physical activity levels (P=0.67). The improvement in HRR was significantly correlated with decreases in body weight, BMI, waist circumference, plasma glucose, serum triglycerides and triglyceride:HDL ratio, but was only independently associated with changes in weight and plasma glucose concentrations.
Conclusion – In addition to improving a range of well-accepted cardiovascular and metabolic risk factors, weight loss also improves HRR after exercise, a less well-recognised risk factor.
Acknowledgment – This work was funded by a Medical Research grant from Meat and Livestock Australia. None of the authors had any conflict of interest.