the effect of islamic praying on heart rate variation in adult muslims

Introduction: the flexibility of the heart is important for cardiovascular health. the heart rate variation (hrv) is a metric of heart flexibility. muslims perform praying (namaz) which has some significant effects on general health regularity. the study aimed to assess the impact of real namaz on hrv. materials and methods: eighty-two participants who performed namaz daily were categorized into three groups, including more minor, more than, and equal to the normal cortisol level range based on salivary cortisol. the electrocardiography was recorded before, during (divided into standing, bowing, prostration, and sitting positions), and after a four-cycle namaz around noon. the linear and non-linear features of hrv were extracted. results: the two-way analysis of variance showed that the standard deviation (sd)1 and sd2 of the poincare plots of all groups increased after namaz (p<0.0001). during namaz, the indexes of sympathetic tone decreased in the prostration and bowing compared to the sitting and standing positions (p<0.00001). the sd of the mean of the r peaks interval, sd1, and sd2 of the poincare plot also increased in those comparisons (p<0.00001). in addition, the spectral entropy was decreased in the bowing and prostration compared with standing and sitting positions (p<0.001). conclusion: namaz significantly increased the performance of the cardiovascular system and decreased the effect of daily stress on it.