Discovering your target heart rate zone is the best method to find your exercise intensity level. It’s important to find a balance between pushing your body to the limit and being lazy. Finding this sweet spot will help people with low fitness levels gain endurance without risking injury.

The links below will show you how to calculate your target heart rate zone, printout charts and worksheets.

Download this chart in high-pixel 11" BY 17"

Sources:  Personal Fitness Training: Theory & Practice and ACSM's Guidelines for Exercise Testing and Prescription