Timing exercise to match body clock chronotype—the natural predisposition to morning or evening alertness—may lower cardiovascular disease risk among those who are already vulnerable, suggests research published in the open access journal Open Heart. Chronotype alignment boosted sleep quality and lowered risk factors, such as high blood pressure, fasting glucose, and ‘bad’ cholesterol, more effectively than mismatched exercise timing, the trial results indicate. The findings prompt the researchers to suggest that individual chronotype assessment should be included in exercise prescriptions for those who are at risk of cardiovascular disease.