Although the treadmill is only moving at 4.4 miles per hour, I feel like I cannot possibly go on. The grade just rose to 16.3, and my legs, though barely shuffling, are moving with great difficulty.

Thanks to the proliferation of smartwatches and fitness trackers, it’s never been easier to log your heart rate while running: Simply don the device, start your workout, and watch those beats per ...

I tested them against the Apple Watch and the Polar chest strap to find out whether you can trust them for your workouts. I’d been wearing my AirPods Pro 3 for months without ever touching one of its ...