High-intensity interval swimming improves cardiovascular endurance, while aquatic resistance training enhances muscular strength in older adults

The aim of this study was to examine the effects of free swimming (FS), aquatic resistance training (ART), and their combination (FS&ART) on the body composition, blood pressure, and physical fitness of older adults. The study employed a randomized controlled design, comparing three experimental groups with a control group. Eighty volunteers aged between sixty and seventy years (age: 66.2 ± 2.3 years; body mass index: 25.8 ± 4.3 kg/m²) participated in the 16-week intervention, consisting of two weekly sessions. Assessments were conducted at baseline and post-intervention, including anthropometric measurements, blood pressure readings, and the Senior Fitness Test. Significant differences were found between groups in post-intervention considering the chair stand test (p = 0.017; ES = 0.125), arm curl test (p = 0.029; ES = 0.111), 8-foot up and go test (p = 0.042; ES = 0.102), and walk test - 6 min (p = 0.005; ES = 0.156). Specifically, both ART (+ 20.1%; p < 0.05) and FS&ART (+ 19.5%; p < 0.05) showed significantly greater improvements in the chair stand test compared to the control group. Similarly, ART (+ 23.1%; p < 0.05) and FS&ART (+ 18.7%; p < 0.05) performed better than the control group. FS&ART also exhibited a significant improvement over the control group in the 8-foot up-and-go test (+ 14.6%; p < 0.05). In the 6-minute walk test, FS (+ 19.4%; p < 0.05) and FS&ART (+ 15.9%; p < 0.05) both significantly outperformed the control group. This study found that FS improves cardiovascular endurance, while ART enhances muscular strength and endurance in older adults, with combined benefits for agility, suggesting integration of combined modalities into community wellness initiatives for enhanced physical fitness and health outcomes.