Impact of a Multidomain Outdoor Exercise Intervention on Cardiovascular Health and Functional Capacity for Healthy Aging: A Randomized Controlled Trial (ACTIVA-Senior Study)

<b>Background</b>: Population aging calls for effective, scalable interventions to enhance cardiovascular and functional health in older adults. <b>Objective</b>: The objective was to evaluate the effects of an 18-week multidomain outdoor exercise program on cardiovascular and functional outcomes. <b>Methods</b>: Fifty-two participants (mean age: 66.0 ± 5.1 years; BMI: 27.2 ± 3.7 kg/m²; body fat: 35.0 ± 7.0%) were randomized into intervention (n = 26) and control (n = 26) groups. The intervention involved twice-weekly, 60 min outdoor sessions integrating resistance (30-60 s isometric holds), aerobic training (Borg RPE 6-7), balance, and cognitive exercises. <b>Results</b>: Forty-six participants completed the study (intervention: n = 25; control: n = 21). The intervention group (mean age 65.6 ± 5.3) demonstrated significant improvements compared to the controls (mean age 66.4 ± 4.9): a systolic blood pressure reduction of 17.4 mmHg (95% CI: -21.9 to -12.9, <i>p</i> < 0.001, ηp² = 0.376), diastolic blood pressure reduction of 9.2 mmHg (95% CI: -12.1 to -6.3, <i>p</i> < 0.001, ηp² = 0.248), and Six-Minute Walk Test improvement of 64.7 m (95% CI: 45.9 to 83.5, <i>p</i> < 0.001, ηp² = 0.463). Body composition showed modest but significant improvements in percent body fat (-1.3%, <i>p</i> = 0.007) and visceral fat levels (-0.9 units, <i>p</i> = 0.002). However, these changes were not significant between groups. The Number Needed to Treat was 2.2 for clinically significant blood pressure reduction and 1.4 for meaningful functional improvement. <b>Conclusions</b>: The ACTIVA-Senior multidomain outdoor intervention led to clinically meaningful improvements in cardiovascular function and functional capacity. The results suggest strong potential for scalable outdoor aging interventions. These findings support the integration of structured outdoor exercise programs into healthy aging strategies and public health initiatives.