Using the following formula you will first find your Minimum Training Heart Rate, then your Maximum Training Heart Rate. 220 - Age = Maximum Heart Rate Max Heart Rate - Rest. Heart Rate x Intensity + Rest. Heart Rate = Training Heart Rate For example: Sara is 33 yrs old, has a resting heart rate of 75 and she's just beginning her exercise program (her intensity level will be 50% - 60%.)   Sara's Minimum Training Heart Rate: 220 - 33 (Age) = 187 187 - 75 (Rest. HR) = 112 112 x .50 (Min. Intensity) + 75 (Rest. HR) = 131 Beats/Min.   Sara's Maximum Training Heart Rate: 220 - 33 (Age) = 187 187 - 75 (Rest. HR) = 112 112 x .60 (Max. Intensity) + 75 (Rest. HR) = 142 Beats/Min. Sara's training heart rate zone will be 131-142 beats per minute   Intensity Level 50% - 60%     Beginner or low fitness level 60% - 70%     Average fitness level 75% - 85%     High fitness level