Effect of aerobic physical training on cardiac vagal reactivation in young sedentary

Abstract

The objective was to compare the cardiac parasympathetic behavior during the recovery phase of an incremental exercise (IE), before and after an aerobic training (AT) program. For this, fifteen healthy sedentary young people, aged between 18 and 25 years, underwent the IE in treadmill with initial velocity of 4.0 km/h and increments of 1.0 km/h/min until exhaustion. After the MIE the heart beats were recorded during 10min. The register was sent to a computer to be processed the heart rate variability (HRV) analysis using the index pNN50, RMSSD and HF (u.n.) of the times 0-5min and 5-10min post-effort. After, underwent an AT with 12 sessions of 40min at intensity equivalent to 65% of HR peak. Subsequently, the IE was repeated until they reached the same speed of IE of the first phase before AT. The data were compared using Kruskal-Wallis test with significant level of p<0.05. The HRV analysis 0-5min and 5-10min showed no differences between the data, with: a) 0-5min: pNN50 (0.3±0.7 % pre AT and 0.4±1.1 % post AT), RMSSD (8.4±5.5ms pre AT and 9.6±7.5ms post AT), HF(u.n.) 27.6±17.0% pre AT and 28.2± 13.8% post AT); and b) 5-10min: pNN50 (0.1±0.4% pre AT and 0.4±0.8% post AT), RMSSD (8.0±4.6ms pre AT and 10.6±7.9ms post AT), HF(u.n.) 27.6±18.3% pre AT and 29.8± 17.5% post AT). The application of a short duration AT was not effective to increase the parasympathetic nervous system interference on the heart during the recovery phase after IE.