I’m not a fan of a boring 45 min on treadmill at the same pace. I spend 1/2 that time, but have several 90 sec periods of peak exercise built in. At my age of 56, that means getting my pulse up to 150-160 beats/minute. For me, that’s the treadmill at 3.8 mph and 15% elevation.
The nice thing about exercising to a heart rate target is that it helps challenge you while allowing you to progress in performance. Of course, you should see your doctor before starting such a program.
You can read more here about such HIIT (high intensity interval training).
During moderate exercise, according to the Canadian guidelines, your pulse should rise to about 64 percent to 76 percent of your maximum heart rate; during vigorous exercise, your pulse should hover between about 77 percent and 90 percent of your maximum. More casually, the American guidelines suggest that during moderate exercise, you should be able to “talk, but not sing,” while during vigorous activity, “you will not be able to say more than a few words without pausing for a breath…”
The volunteers were, as it turned out, quite inept at judging intensity. Few maintained a heart rate above 65 percent of their maximum when they were supposedly exercising moderately; even fewer reached a heart rate above 75 percent of maximum during their version of vigorous exercise.
The standard formula for determining maximum heart rate — 220 minus your age — is notoriously inaccurate. A more precise formula, as described here, is 211 minus 64 percent of your age.
That means when I get my pulse up to 160, I’m at 91% of maximum. At that pulse, I’m really huffing and puffing and can’t carry on a conversation.
But that kind of exercise is the best stress relief in the world (OK, maybe second best!)