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Adherence to heart rate-based intensity parameters predicts cardiovascular response to 12-weeks of aerobic cycling training in sedentary older adults

Year: 2026

Type: article

Abstract: Exercise improves cardiovascular health in older adults, yet variability in responsiveness remains. This study tested if prescribed exercise intensity adherence predicts individual differences in cardiovascular fitness gains following an intervention. From 2017 to 2022, nineteen sedentary older adults (69.78 ± 6.47 years) completed a 12-week aerobic cycling program in the Exercise Research Laboratory at the Atlanta VA Hospital. Participants trained 3× weekly, progressing from 20 to 45 min per session. Target intensity, expressed as percent heart rate reserve (HRR), increased from 50% to 80%. Cardiovascular fitness ( V ̇ O 2max ) was estimated pre- and post-intervention using the YMCA submaximal test. Attendance reflected the proportion of completed sessions. Intensity-based adherence was derived from the ratio of median HR to prescribed HR across sessions, modeled over time, and expressed as change from session 1 to 36. Estimated V ̇ O 2max increased significantly (21.51 ± 8.77 to 25.80 ± 9.42 ml/kg/min, p < .001). Attendance exceeded 90% and did not predict estimated V ̇ O 2max change, whereas HR adherence to prescribed intensity significantly predicted improvement (R 2 = 0.42, p = .01). Cardiovascular adaptations in older adults relate more strongly to prescribed HR adherence than attendance. Objective, trajectory-based adherence metrics may refine exercise prescriptions and improve prediction of individual responsiveness. • Cycling training improved VO2max by ~20% over 12 weeks. • Intensity adherence, not attendance, predicted VO2max gains in older adults. • Polynomial adherence trends explained 42% of VO2 variance.

Source: Preventive Medicine Reports

DOI: 10.1016/j.pmedr.2026.103388

Authors: Tom S. Novak, Caroline Quan, Keith McGregor, Kevin Mammino, Medina Bello, Joe R. Nocera

Institutions: Emory University, Atlanta VA Medical Center, University of Alabama at Birmingham, Center for Clinical and Translational Science

Language: English

Topic: Cardiovascular and exercise physiology

Subfield: Complementary and alternative medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,610