Cardiovascular Risk Factor Responses to Aquatic Exercise in Overweight Women: A Review of Physiological Adaptations

Abstract

Background: Overweight and obesity are associated with an increased risk of cardiovascular disease through adverse changes in lipid profiles, glucose metabolism, and insulin sensitivity. Aquatic exercise may provide a safe, low-impact strategy for improving these cardiovascular and metabolic risk factors in overweight women. Objectives: This study aimed to investigate the effects of aquatic exercise on cardiovascular risk factors in overweight women, focusing on physiological adaptations. Methods: This clinical trial used an interventional pretest-posttest design. During the announced call, 30 eligible overweight women (BMI ≥ 25) aged 50 - 60 years were purposively selected from 60 individuals who expressed willingness to participate and were randomly assigned, using a random-number generator, to a control group (CG) or an aquatic exercise group (EG) (n = 15 each). The EG participated in a structured aquatic exercise program for 8 weeks, three sessions per week, with each session lasting 60 minutes and exercise intensity progressing from 45% to 60% of heart rate reserve. CG participants maintained their usual daily activities and refrained from regular exercise. Outcome assessors were blinded to group allocation. Study variables included total cholesterol, triglycerides (TG), glycosylated hemoglobin (HbA1c), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and homeostatic model assessment of insulin resistance (HOMA-IR). Data analysis included analysis of variance, the Shapiro-Wilk test, and Levene's test. Statistical significance was set at P ≤ 0.05. Analyses were performed using SPSS version 22. Results: Aquatic exercise produced significant Group × Time interactions for total cholesterol (P = 0.001), LDL-C (P = 0.001), HbA1c (P = 0.001), and HOMA-IR (P = 0.001). No significant Group × Time interactions were observed for triglycerides (P = 0.072) or HDL-C (P = 0.081). Conclusions: Aquatic exercise is a safe and effective alternative for overweight women and may help reduce cardiovascular disease risk by improving selected lipid and metabolic risk factors and insulin sensitivity.