Okay, I suppose we could discuss it a bit more than that.
As readers may recall, Crabby doesn't automatically endorse every health or fitness related gadget that comes to her attention. She lusts after them, but doesn't always spend actual money to get them herself. She didn't urge you to run out and buy that RESPeRATE thingy, right, 'cause it cost three hundred bucks?
But if you're trying to get regular cardio exercise, and you know your target heart rate zone (and if you don't, go here), then a heart rate monitor is a really convenient way to stay in the right range. And they're not expensive either, if you shop around and settle for the most basic model.
Crabby loves the low-end Polar monitor, which does absolutely nothing except measure your heart rate. Because it has so few functions, the digits on the wrist band are actually big enough to read. (Not true of the fancier models). Doing some comparision shopping on-line, she bought it a couple of years ago for less that $40, U.S. (As though Crabby would be suddenly quoting prices in yen. But she wants to remain sensitive to her most-valued international readers).
For most models, you do have to wear a chest strap. Crabby didn't buy a monitor for years because of the chest strap, assuming it would be terribly uncomfortable. But it's really not bad at all.
Especially for non-runners, a heart rate monitor can ensure your "brisk walk" is really brisk enough to be aerobic. Often you're doing more than you think you are. But if it turns out you're not, at least you'll know it. You can either step it up, or just embrace your slackitude. Either way.
One caution, however: neither the monitors nor the "target zones" are a hundred percent accurate. For example, when Crabby gets going with good music, charging up a big hill, the heart rate monitor claims she is actually exceeding her maximum possible heart rate (not merely her target zone) and should be in full-on cardiac arrest. Crabby, being foolish, just ignores the scary number because she's been doing the same thing for years and figures the number must just be wrong. She hasn't died yet.
Don't you do that though. It's dumb . If the number gets too high, slow the f*ck down.