Effect of 5 weeks of high intensity intermittent training on HRV and RPP parameters in girls Aged 7 to 9 Years: Relation to overwaight in childhood

Overweight and obesity in children are the underlying cause of cardiovascular problems that occur through Autonomic Nervous System (ANS) dysfunction, However, physical training has a beneficial effect on the ANS. These changes can be measured through Heart Rate Variability (HRV) indices. Accordingly, the present study aimed to investigate the effect of five weeks of High-Intensity Interval Training (HIIT) on HRV and Rate Pressure Product (RPP) of overweight girls.

In this research, overweight students in the range of +2 < BMI Z- SCORE <1+ participated in the Experimental and the Control groups. Before and after five weeks of HIIT intervention, the participants underwent the Shuttle Run test to estimate maximal oxygen consumption and the Six-Minute Walking test to estimate maximal fat oxidation (MFO) during exercise. Root Mean Square of Successive Difference (RMSSD) of the R-R wave interval of the heartbeat was recorded to measure resting HRV and also systolic blood pressure and heart rate were recorded to measure resting RPP in the first and the last week. Data analysis was done using dependent t-tests and analysis of covariance (ANCOVA) with a significance level of p<0.05.

the results showed that in the training group, five weeks of HIIT intervention caused significant changes in RMSSD, RPP, and MFO of overweight girls (P<0.05). However, in the control group, the indices did not change significantly (P>0.05).

RMSSD, RPP, and MFO indices can be used as suitable and efficient alternatives to identify children at risk and therapeutic processes before puberty.