These days, it may seem like there’s a million different data points that you’re supposed to keep track of—hello, steps, sleep, and recovery scores!—and it’s difficult to know which ones are worth ...

That tension becomes especially clear with heart rate zone training, a popular five-tier system that endurance athletes use to measure effort and fine-tune performance. The well-known formula is ...

Whether due to stress or an intense cardio workout, most of us have felt our heart racing from time to time. A rise in your heart rate can be perfectly normal given outside circumstances. However, ...

Did you know there’s a number that might let you know how stressed you are, whether you have a cold coming on and how to get into the zone if you’re about to present at a big meeting? You can find ...