Impact of lifelong exercise "dose" on left ventricular compliance and distensibility.
Level 4 - case-series / case-control
Cross-sectional physiological study comparing stratified cohorts based on retrospective exposure
PubMed 25236519 · doi:10.1016/j.jacc.2014.03.062
What was done
Healthy older adults (n = 102) were recruited and categorized into four lifelong exercise groups: sedentary (<2 sessions/week), casual (2 to 3 sessions/week), committed (4 to 5 sessions/week), and competitive Masters athletes (6 to 7 sessions/week). Left ventricular pressure-volume relationships and Frank-Starling curves were measured using invasive right heart catheterization and echocardiography during preload manipulation with lower body negative pressure and rapid saline infusion.
What was found
Peak oxygen uptake and LV mass increased across escalating exercise doses with minimal change in systolic function. Baseline LV distensibility was 21% higher in committed exercisers and 36% higher in competitive exercisers compared to sedentary individuals. Group LV stiffness constants were 0.062 ± 0.039 (sedentary), 0.079 ± 0.052 (casual), 0.055 ± 0.033 (committed), and 0.035 ± 0.033 (competitive). Casual exercise did not prevent LV stiffening compared to sedentary aging, whereas committed and competitive exercisers demonstrated preserved LV compliance and reduced stiffness.
Why it matters
This study provides a physiological dose-response threshold for cardiac aging, showing that 4 to 5 sessions per week over a lifetime are required to prevent age-related left ventricular stiffening, while casual exercise (2 to 3 sessions per week) is insufficient.
Limits
The study is cross-sectional and relied on retrospective recall to define lifelong exercise dose. The sample size was modest (102 total across 4 groups), and survival or selection bias among lifelong athletes cannot be excluded.
Cited by
- supports Exercising 5 hours per week including high-intensity interval training can reverse cardiac aging by 20 years.