If you're looking for a leisure-time activity that has an added benefit of protecting you against heart disease, try biking. A Danish study followed more than 45,000 recreational cyclists, ages 50 to 65, for 20 years. The participants who cycled regularly for either pleasure or commuting, had 11 to 18 percent fewer heart attacks than non-cyclists. Additionally, adults who took up cycling for the first time saw a 26 percent decrease in their cardiovascular risk within five years when compared with non-cyclists. It's already known that incorporating bicycling into a workout routine is good for your heart. But this study looked at people who enjoyed outdoor bicycling as a recreational hobby or as a way to commute instead of a conscious means of exercise. What's more, even once-a-week rides of only half an hour were associated with a reduced heart attack risk. Because the study is observational, it can't prove that bicycling prevents heart attacks, but it does suggest a beneficial relationship between bicycling and heart health. The findings are supported by another study in which middle-aged and older adults in Sweden who commuted to work via bicycle were less likely to have a high body mass index, high blood pressure, high cholesterol, diabetes, or prediabetes than those who commuted "passively," such as by car or public transportation. The researchers found that the cyclists' risks decreased as their rides' frequency and duration increased, consistent with a dose-response relationship.