Am expecting to be shot down in flames here, but bear with me....
Self isolation advice is to stay at home for a week and not even go out for a walk. I totally get why public places should be avoided etc, but given the risk of airbourne transmission is being with 2-3ft of someone for 15 mins this wouldn't happen if I went for a run or a walk. It would be very easy for me to go for a walk in a rural area / woods etc where I would be unlikely to see many people, and I certainly wouldn't be getting close to them.