Sunday, February 24, 2008
"Forced, continuous, endurance exercise induces your heart and lungs to 'downsize' because smaller allows you to go further... more efficiently... with less rest... and less fuel.
So what's wrong with increasing durational capacity through downsizing? Instead of building heart strength, it robs it of vital reserve capacity. Your heart's reserve capacity is that portion of its maximal output that you don't use during usual activity. To reuse the car analogy, your reserve capacity is the 'pedal' that you have left on your accelerator before you hit the floorboard when you're cruising at your typical speed.
So if you downsize your heart and lungs you have traded reserve capacity for efficiency at continuous duration. This then forces them to operate dangerously close to their maximal output when circumstances challenge them. For your heart, this is a problem you don't need.
Heart attacks don't occur because of a lack of endurance. They occur when there is a sudden increase in cardiac demand that exceeds your heart's capacity."
- Al Sears, M.D. from "PACE: Rediscover Your Native Fitness" (pg. 8-9)
Posted by Boris at 8:12 PM