Training Adaptations in Sedentary Adults: An 8-Week Randomized Controlled Trial Comparing Walking and Cycling Protocols

Abstract

Background: Physical inactivity is a major modifiable risk factor for cardiovascular disease. Aerobic exercise is widely recommended to improve cardiovascular health; however, comparative adaptations between walking and cycling protocols in sedentary adults remain insufficiently explored. Objective: To compare cardiovascular and autonomic adaptations following an 8-week structured walking versus cycling program in sedentary adults. Methods: Sixty sedentary adults (20–45 years) were randomized into Walking (WG; n = 20), Cycling (CG; n = 20), and Control (CON; n = 20) groups. Exercise groups trained 5 days/week for 8 weeks at 50–65% HRmax with progressive duration (30–45 minutes). Primary outcomes included VO₂max, resting heart rate (RHR), systolic blood pressure (SBP), and diastolic blood pressure (DBP). Secondary outcomes included body mass index (BMI), body fat percentage, and heart rate variability (HRV). A 3 × 2 repeated-measures ANOVA assessed group × time interactions. Results: Significant group × time interactions were observed for VO₂max (η² = .28), SBP (η² = .24), DBP, RHR, and HRV (p < .01). Cycling demonstrated greater improvements in VO₂max (Δ +5.8 mL·kg⁻¹·min⁻¹) compared to walking (Δ +4.1 mL·kg⁻¹·min⁻¹; p = .02). Walking produced slightly greater SBP reduction (−9.2 mmHg) compared to cycling (−7.6 mmHg; p = .04). No significant changes occurred in the control group. Conclusion: Both walking and cycling significantly improve cardiovascular health in sedentary adults. Cycling enhances aerobic capacity more substantially, while walking may provide superior blood pressure reduction. These findings support modality-specific exercise prescription.