A study has found that men need to exercise twice as much as women to achieve the same reduction in coronary heart disease risk. Analyzing physical activity records from over 80,000 people, researchers found that women who exercised 250 minutes per week saw a 30% drop in heart disease risk. In contrast, men needed to exercise for 530 minutes, nearly nine hours, per week to see the same effect. The findings suggest that healthy living guidelines should consider these sex differences.