Vivoactive 5 Continuous Heartrate Monitoring

I haven't been able to find a way to turn off the continuous heartrate monitoring, but still have heartrate monitoring for activities. So every time I go for a walk throughout the day or go for a run or strength train, I have to remember to go into the app and turn on the heartrate monitor, then go back in and turn it off. 

Does anyone know of a way to turn off the constant monitoring but still have the monitor for activities?