Originally Posted by
CbadRider
...Your heart is a muscle. Saying it only has a predetermined number of beats is like saying your bicep has a predetermined number of contractions and your arm will stop working if you don't exercise it hard enough.
No it isn't. You bicep doesn't have resting flexing rate that is lowered by intense exercise. The more frequently you move it, the sooner it will stop working regardless of exercise, if it has a fixed number of flexes built in. I want to ensure I have enough bicep flexes to keeping hoisting brewskies for the duration...