Runners, cyclists and gym-goers with wearable fitness trackers are no doubt familiar with the five "heart rate" zones.

Heart rate zones are a way to describe how hard you're working during a cardio workout, like running or cycling. The faster your heart beats, the harder you're working. So an easy jog might have you ...

Add Yahoo as a preferred source to see more of our stories on Google. Understanding our body’s target heart rate zones and how they change as we age is crucial for getting the most out of our workouts ...

These days, everyone from the average Susan to the hardcore data-loving wellness enthusiast has the technology to track just about anything in the name of self-optimization. A ring wearable tells you ...

For years, the gold standard for gauging workout intensity was often a simple "how you feel" metric. And while perceived exertion is still used by many exercisers and athletes today, it’s a bit like ...

Lastly, zone 5 is 90 to 100 percent of your heart rate max, so you’ll feel winded, like you’re at your most intense effort. The issue: Many runners (particularly women) report that their fitness ...