Only a few wearables deliver accurate heart metrics that can help you make training decisions. A new study reveals which ones measure up.

At the top of the swing, the kettlebell should briefly feel weightless before gravity begins to pull it back down. Before it starts swinging back down, inhale to brace. Push your hips back, staying ...

Your iPhone can track steps using a built-in accelerometer. You can track your steps in the Health app, where you can see a range of exercise metrics.