Acute physiological responses in pregnant women during exercises in different positions

Abstract

Objective: This study measured acute physiological responses in pregnant women during short duration exercise in the supine (Sup), side-lying (Side), sitting (Sit), and standing (Std) positions.

Methods: In a cross-sectional study, 42 healthy pregnant women were divided into 3 groups of 14 persons each: G1, G2, and G3 (first, second, and third trimester, respectively). Baseline assessments were performed following a 30-min rest in the sitting position. Subsequent measurements were then obtained while exercising, without resistance, in the Sup, Side, Sit, and Std, respectively. Physiological parameters, including heart rate (HR), minute ventilation ( ${\dot{V}}_E$ ), oxygen consumption ( $\dot{V}{O}_2$ ), carbon dioxide production ( $\dot{V}C{O}_2$ ), and oxygen pulse ( $\dot{V}{O}_2$ /HR), were collected using the indirect calorimetry.

Results: Comparing resting values, all groups had a significantly increased (1) HR, ${\dot{V}}_E$ , and $\dot{V}C{O}_2$ during the Std, (2) $\dot{V}{O}_2$ values during the Sit and Std, and (3) O₂ pulse values during short duration exercise in all positions except the Std, whereas only G2 and G3 had a significantly decreased HR during the Sup.

Conclusion: This study points that acute physiological responses to the positional challenge similarly occur in all trimester of pregnant women. Short duration exercise in the Std positions exerts more physiologic stresses on cardiorespiratory functions than in the Sup, Side, and Sit positions.

Keywords: Indirect calorimetry; oxygen pulse; pregnant women; trimesters.