Exercise Intensity and 5-Yr Trajectories in Peak Oxygen Uptake in Older Adults: Analysis from the Generation 100...

The long-term impact of exercise training on change in cardiorespiratory fitness (CRF) with age remains uncertain. Given that CRF appears to be one of the strongest predictors of current and future health, we examined the differences between high-intensity training (HIT) and moderate-intensity training (MIT) on 5-yr changes in CRF in older adults.

In this post hoc observational analysis of the Generation 100 Study, we included 500 participants (52% women; aged 70-77 yr) who consistently reported engaging in HIT or MIT for 5 yr. Participants underwent clinical assessments, including CRF measured as peak oxygen uptake ( ) at four timepoints. Linear mixed model was used to examine the longitudinal change in and differences in trajectories across the 5-yr period.

Across 5 yr, men reporting HIT and MIT showed declines of -3.1% ( P = 0.007) and -7.7% ( P < 0.001), respectively. Women reporting HIT showed no change ( P = 0.96) in , whereas those reporting MIT showed a decline of -4.6% ( P < 0.001) . At 5 yr, the difference in was 1.31 mL/kg/min (95% confidence interval [CI] 0.17-2.45) and 1.33 mL/kg/min (95% CI 0.28-2.37) in favor HIT in men and women, respectively. In exploratory analyses, higher self-reported exercise intensity was associated with 1.11 (95% CI 0.60-1.62) and 0.64 (95% CI 0.22-1.06) mL/kg/min smaller decline in in men and women, respectively, whereas weekly exercise duration showed weaker and inconsistent associations.

Among men and women aged 70-77 yr, consistent engagement in aerobic exercise training was associated with more favorable age-related trajectories , with HIT showing the smallest declines over 5 yr. Exploratory interaction analyses suggested that exercise intensity may become increasingly important over time for preserving .