What is the formula that determines your estimated maximum heart rate?

220-(age)=maximal heart rate

If you want to know your optimal training range take that number and multiply it by .62 and .9

Example: 220-37=183

183x.9=165

183 x .64=117

This respresents the heart rate values that fall between 64% and 90% of maximal heart rate which is the range generally recommended to achieve aerobic fitness. It's good to stay in between this range for atleast 20 consecutive minutes.