Objective: To evaluate the association of physical fitness (PF) and cardiometabolic risk (CMR) with heart rate recovery time (ΔHRR) in Chilean school aged children.
Methods: Cross-sectional study in 478 6-9 years old children participants. We measured weight, height and abdominal circumference. Fitness was measured using the 6MWT, grip strength and leap forward without impulse tests; PF z-scores were calculated. Heart rate (HR) was monitored and recorded during the 6MWT. ΔHRR was calculated as the difference between HR before and one minute after test; blood glucose, insulin, triglycerides and HDL-cholesterol were measured. Waist circumference, CMR-z and HOMA were calculated.
Results: Absolute ΔHRR and CMR-z measures in normal weight children were lower than in obese children (p < 0.05 and p < 0.01, respectively). In obese children, ΔHRR was also associated with grip strength/weight (r = -0.6, p < 0.01) and PF-z (r = -0.6, p = 0.04). Insulin and HOMA were significantly related to ΔHRR (r = 0.3, p < 0.001), especially in overweight and obese children. ΔHRR values were not associated with CMR-z.
Conclusions: A significant relationship between ΔHRR with fitness and insulin sensitivity in overweight and obese school children was found. We consider that these results support the need to measure these variables in overweight and obese children, in order to strengthen the need for early prevention.