Want to take the guesswork out of training? Then you need a heart-rate monitor. Here's how to use it.

We tested the best heart rate monitors so you can focus on the miles, not the math.

Ambient light shines through your skin and produces a video stream that looks like a dark red rectangle. Though it may be imperceptible to us, the color changes ever-so-slightly as your heart beats.

A new video monitor utilizes novel technology to measure breathing and heart rate by capturing images of your face. The implications of such contactless monitoring could be a disruptive force in ...