220-age has been debunked. It may have some application across a population but it's useless for individuals. You are better off finding your lactate threshold HR and basing your training levels from that.
See:
https://www.trainingpeaks.com/blog/j...setting-zones/
To find your LTHR do a 30-minute time trial all by yourself (no training partners and not in a race). Again, it should be done as if it was a race for the entire 30 minutes. But at 10 minutes into the test, click the lap button on your heart rate monitor. When done, look to see what your average heart rate was for the last 20 minutes. That number is an approximation of your LTHR.
Or find your actual HRmax, but that's quite painful.