For bodybuilders and fitness enthusiasts, changing body composition often reflects hard work and discipline—but knowing body composition is useful for anyone, and for more than just bragging rights.

Thanks to the ever-improving world of fitness trackers and apps, you've never had more access to personal health data. But which of the dizzying number of markers and metrics should you really be ...

Smart scales track changes in your muscle mass, body fat percentage and other health metrics — but how do smart scales work, and how accurate are they? When you purchase through links on our site, we ...