# Heart rate response and recovery during exercise and dementia risk: a prospective UK biobank study

## TL;DR

A study found that better heart rate response and recovery during exercise are linked to a lower risk of dementia and slower cognitive decline.

## Contribution

This study is the first to show a link between heart rate recovery during exercise and reduced dementia risk in a large population.

## Key findings

- Higher HRR index and recovery ratio were associated with reduced all-cause dementia risk.
- Higher HRR index was linked to slower cognitive decline in processing speed, reasoning, and memory.
- Recovery ratio was associated with slower decline in reasoning and memory.

## Abstract

The heart rate response/recovery (HRR) index, a common indicator for cardiovascular health during exercise, has been linked with neurocognitive disorders and mortality. However, the relationship between HRR index and dementia remains unknown. Electrocardiogram data from 46,348 middle-aged and older adults from the UK Biobank were analyzed following a standardized submaximal exercise stress test (15-second baseline, 6-minute exercise, and 1-minute recovery). The HRR index was calculated as the product of heart rate responses ratio during exercise (peak/resting heart rate) and recovery ratio (peak/recovery heart rate). We found that 519 participants were ascertained with dementia, including 232 with Alzheimer’s disease (AD) and 85 with vascular dementia (VaD) during a median follow-up period of 12.62 years. Higher HRR index and recovery ratio were significantly associated with a reduced risk of all-cause dementia (HR: 0.72, 95% CI: 0.54–0.94, P = 0.017; HR: 0.75, 95% CI: 0.57–0.99, P = 0.018), but not with incident AD or VaD, respectively. In addition, higher HRR index was significantly correlated with slower cognitive decline in processing speed, reasoning, and memory (β:2.39, 95% CI: 0.28–4.49, P = 0.027; β: 2.12, 95% CI: 0.26-4.00, P = 0.027; β: 0.03, 95% CI: 0.02–0.05, P < 0.001), while the recovery ratio was significantly correlated with slower cognitive decline in reasoning and memory (β: 1.91, 95% CI: 0.04–3.79, P = 0.045; β: 0.03, 95% CI: 0.01–0.04, P < 0.001). Higher HRR index and recovery ratios are associated with a decreased risk of incident dementia and appear to have beneficial effects on delaying cognitive decline. The possible mechanisms for this may involve autonomic function and neurovascular health.

The online version contains supplementary material available at 10.1038/s41598-025-22299-2.