Heart Rate Recovery In Normal And Obese Males With And Without Parental History Of Cardiovascular Disease

Background: Parental history of cardiovascular disease (CVD) and obesity is associated with delayed parasympathetic nervous system reactivation after exercise. Heart rate recovery (HRRe) after a minute of exercise is inversely related to cardiovascular events. Aim: To determine the effect of body mass index (BMI) and parental CVD history on HRRe in apparently healthy young Indian males. Method: The present cross-sectional experimental study involved 100 males, aged18-25 years. Subjects were divided into two equal groups based on the parental CVD history-(i) Parental CVD history present, and (ii) Parental CVD history absent. Each of these groups were further divided into two equal sub groups based on BMI-(a) BMI <23kg/m2, and (b) BMI 25 kg/m2. Participants exercised on the treadmill at variable speeds and grades to achieve their target HR (THR). THR was calculated by adding 60-90% HR-reserve (HRR) in their basal HR (BHR). HRR was calculated by subtracting maximal HR (MHR) from BHR. MHR was estimated by the formula: 208-0.7 x age. The HRRe was calculated by subtracting the immediate postexercise HR with the HR after a minute of rest postexercise. ANOVA with post-hoc Tukey was applied and a P value <= 0.05 was considered as statistically significant. Results: HRRe value was significantly lesser in subjects having a positive parental history of CVD than the subjects with no parental history of CVD, irrespective of BMI. Also, HRRe was inversely related to BMI. Conclusion: Not only obesity but also a family history of CVD impacts the recovery of HR after vigorous-intensity exercise.