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 ...

You can even go a step further and add these customized ranges to your Strava account so everything is in sync. (On the ...

Anyone who has ever climbed aboard a treadmill or elliptical trainer at the gym is familiar with the little charts or electronic displays that provide information about "maximum" or "target" heart ...