EFFECTS OF EXERCISING POSTURE ON HEART RATE AND ENERGY EXPENDITURE IN PREGNANT THAI WOMEN

Abstract

The aim of this study was to measure heart rate (HR) and metabolic equivalent (MET) during exercise in supine (Sup), side-lying (Side-lying), sitting (Sit), standing (St) and walking position at the 1st (G1), the 2nd (G2), and the 3rd (G3) trimester in pregnant Thai women. Forty- two healthy active non-smoking pregnant women participated in this study and divided into G1, G2 and G3 groups depending on mean gestational ages at the time of testing. The values for HR and MET were measured using indirect calorimetry (IC, gas analyser) at rest and during exercise. Baseline assessments were made in the sitting recumbent position after a 30-minute stabilization period. Sequential measurements were then obtained in the following exercise positions; Sup, Side-lying, Sit, St and walking position, respectively. At rest compared with exercising in Sup position, the subject had tendency to decrease in HR, but statistically significant difference was found only in G3 group (P<0.05). St and Walking accelerated and increased HR more than the other three positions with the same of patterns in all gestation groups. The percentage of change in MET relative to resting position was significantly higher in walking than the other positions in all gestation groups (P<0.05). Our data strongly correlates with the American College of Obstetricians and Gynecologists guideline that recommends avoiding the Sup position post G1. We found walking to be the most spending cost of energy with respect to maternal MET output. Thus, we highly recommend pregnant women walk on a regular basis throughout pregnancy as this will also help maintain their aerobic fitness during pregnancy.
(Journal of Sports Science and Technology 2014;14(1): 145 -154 ) KEYWORDS: Pregnant woman, Heart rate, Metabolic changes, Body posture