State of the Heart: Knowing How to Listen to Your Ticker

Mio Shape Select strapless heart-rate-monitor watch ($129.99).

Others start at $69.99.

Credit: Getty Images

Maybe you're one of those admirable souls who always stays in top shape with daily workouts. (We'll try not to hate you.) Or maybe you're like most of the rest of us, letting things lapse until you have to hit the long, hard road of getting fit from scratch. These are the times when new demands are put on your heart, and when that pounding in your chest can get more than a little alarming. A fitness obsessed friend may suggest you strap a heart monitor on to keep track of how the old ticker is responding.

So, just what can you learn from one of these gadgets? The truth is, not as much as your zealous friend may think.

"Heart-rate monitors are not individualized, and they can provide only a rough idea of how you're doing," says Dr. Rita Redberg, a cardiologist at the University of California, San Francisco.

Heart monitors can be appealing, though. For as little as $40, such a device will provide the actual numbers for an on-demand picture of what your heart is doing during and after a workout. Those numbers, however, are just raw data; they lack the context that makes the information useful. For one person, 145 beats per second may be short of an optimum rate; for someone else, it may be dangerously high.

Typically, a monitor comes with a chart to help you map your heart rates (e.g., resting, maximum) within your age range. (It's essentially the same one slapped onto cardio machines at the gym as a sort of one-size-fits-all measurement.) Staying in what may seem an age-appropriate range could be the best thing for you, but even if you're not in great condition, your heart may be capable of going faster, longer than those of others in your age group. Without more detailed data and analysis, heart monitors can't really guide users meaningfully. In fact, says Redberg, "they can be distracting."

Tracking the intensity of a workout isn't rocket science. You can do it yourself simply by developing what's called your rate (or rating) of perceived exertion -- an informal gauge of how hard you're working using "tests" such as the ability to talk without gasping. You can also put a finger on a pulse point, count the number of beats in ten seconds, then multiply by six.

If you're really serious about getting under the hood to see how your heart is doing, a stress test is the way to go, according to a recent Johns Hopkins University School of Medicine study. Many doctors and sports physiologists are qualified to conduct stress tests, which usually involve a treadmill and lots of EKG-style sensors and can give you a detailed picture of your heart's health and how hard you can push it. But unless you are having health problems, don't expect your insurer to pay for the test.

In the end, once your doctor gives you the green light for rigorous exercise, it's essential to remain active without making things overly complicated. To strengthen the heart, says Dr. Cris Slentz, a senior research scientist at Duke University, "the intensity of the exercise doesn't matter as much as the amount." So, as a well-known ad campaign puts it, just do it -- gizmo free.