Fitness intensity can be one of the most subjective areas of working out. From “rate of perceived exertion” (or RPE) to the famous “runner’s high” or getting “in the zone,” these metrics can, at best, ...

When you think of progressing as a runner, you probably think about getting faster and/or going farther, but there’s another variable to consider: running intensity. To Steve Mura, manager of runner ...

The debate about how hard to push during exercise has persisted for decades, with fitness approaches swinging between high-intensity interval training and gentler, steady-state activities. However, ...