Oxygen levels and activity

I run and hike and was diagnosed with Bronchiectasis a year ago. I have both a Pulmonologist and a Cardiologist. My Cardiologist does not want my heart rate to go above 148 if my oxygen is below 90%. I use an Apple Watch and a O2 Ring from VHealth. Is there anyone else out there trying to continue with aerobic exercise and watching heart rate as well as oxygen level?