BMJ Group Apr 16 2025 A brisk walking pace, and the amount of time spent at this speed, may lower the risk of heart rhythm abnormalities, such as atrial fibrillation, tachycardia (rapid heartbeat), and bradycardia (very slow heartbeat), finds research published online in the journal  Heart. The findings were independent of known cardiovascular risk factors, but strongest in women, the under 60s, those who weren't obese, and those with pre-existing long term conditions. Heart rhythm