In both Australia and the USA, heart disease currently remains the number one cause of death, but a large study suggests you could significantly reduce that risk by cycling to work.
A Danish study was conducted over 14 years including over 30,000 people to assess the relationship between physical activity and mortality (risk of death). Even after adjustment for other risk factors, including leisure time physical activity, those who did not cycle to work experienced a 39% higher mortality rate than those who did. Those who cycled to work regularly experienced only half the number of heart attacks than those who reported no cycling.
In Denmark, 70% of young men and women use the bicycle to travel to work over Summer and 46% commute by bicycle all year round!
This study suggests that if it's safe and practical to do so, cycling to work could just make you live longer by reducing your risk of heart attack.