Your heart rate is more uneven than you think. This is what it says about your health

Artem Kirillov is not, by nature, the kind of person to take it easy. “I prefer to push myself further, even if I feel a bit off,” says Kirillov, who is 40, lives in London and works in health tech. For a long time, even as a recreational exerciser, he discounted the need for rest days and pushed through fatigue at the gym, believing that more time spent training automatically meant better results.