Heart to Heart
Q. I’ve been using a heart-rate monitor to exercise at 60% of my maximum heart rate (MHR). What
Would happen if I really went for it and hit 110%.
A. You can’t. “MHR is an absolute limit. You might not think so, though, because the heart rate formula-
220 beats per minute, minus your age – has a 10% margin of error. The only sure way to pin down the
number is to have your doctor administer a treadmill test to exhaustion. Once you know your max, you should train at 60-75 of it. You’ll see a modest effect on your fitness level at 60% and a good effect at 75%
but beyond that you’re wasting effort.