I'd like us to do what the French are doing.
You need to justify why you're out and it needs to be enforced.
I hate to think of the consequences for so many if exercising once a day is banned.
You only need to look on some of the threads on mn though, to see why we've come to this where people are claiming it's fine for them to have two walks a day because they don't see anyone, or their dog is used to three walks a day or they need to go for walks with their children but also need to run every day, so obviously they're exempt from the one form of exercise a day, which a lot of posters are claiming has never been said.
A great many people will claim their situation is different and more important than everyone else's situation because in their heads their needs are more important.
So what if I go to the beach? I'm not harming anyone. So what if I take a drive to that national beauty spot, I'm not harming anyone. So what if I go running when I've already been out with the children, I'm not harming anyone.
The trouble is you are harming everyone, because now we all face the prospect of not being able to go out for exercise at all and for a great many people that's going to be a disaster.
Well done!