Vigorous exercise might produce greater health benefits than moderate workouts. But working out too hard isn't a good idea. A heart-rate monitor can help make sure you reach your target heart rate, but stay in your safety zone. We tested 11 new models, ranging in price from $29 to $200, and found that all had excellent accuracy.
Our test included six chest-strap models, which you wear along with a device on your wrist or in on case a special iPhone app to see your heart rate; four wrist-only models, which you have to touch to get a reading; and one wrist model that provides a continuous heart-rate reading.
Our volunteers wore each monitor while resting and while walking on a treadmill at various intensities. To assess accuracy, we compared heart rates on the monitors with those measured by an electrocardiograph, a device similar to the kind doctors use. Staffers also took the monitors home with them, so we could see how easy they were to use outside of our labs.
All provided a consistently accurate heart-rate reading, but check out the section on types below to pick one that best suits your workout routine. For example, some are better for activities like biking. Swimmers should check with the monitor's website or the user manual. The manual for one model we tested says it's only "splash proof," while others say you can use the device while swimming as long as you don't press any of the buttons while you are in the water.