Recent studies seem to indicate that the human heart muscle hardens with age, and consequently the flexibility necessary to pump blood efficiently becomes progressively reduced. This can be a contributary cause of heart attack and stroke. The study has revealed that endurance sports such as swimming and CYCLING, go a long way toward preventing the progressive heart hardening. The benefits are a result of long term exercise, not something that starts to occur rapidly. So, if you aren't riding much, time to get a little dirt on the gem and start a regular routine.
Dennis Young
Hotaka, Japan