Very sensible vegetable.
We live in a suburb of a big city, but literally right next to a couple of parks and woods. We do have a garden. So does everyone else around here. If the guidelines change, we would obviously stay within our property lines as instructed. Until then, we will go for our daily singular state-sanctioned exercise around the woodlands and parks. It wouldn't make any sense to "reserve" these spaces for people without gardens around here, because there aren't any people without gardens around here.
So in the fantasy full-lockdown-do-not-leave-your-property scenario, you'd have neighbours in every house perambulating round and round their own gardens in relatively close proximity to each other, whilst the parks and woodlands are completely empty (except for the people from elsewhere who don't have gardens, who could drive to the parks... oh wait, that's a no-no too 🤔).
Furthermore, in our specific situation, we are able to access the parks and woodlands, and move around them freely, without having to touch any handrails, gates, stiles or other contaminated objects.
Also, I have these things called windows. When deciding a good time to exit my property to go on our daily singular state-sanctioned exercise, we can look out of the window to see if the pavements are filled with perambulating humans (clue: they're not, because it's a suburb) in order to not barge out into a crowd. If there was a crowd of humans swarming along my pavement to the park, I'd decide not to go out. (This happened at the weekend, where we arrived at our other local park via one of the little side entrances, saw that it was busy on the main paths that non-locals use, and so we went home).
Finally, our neighbourhood actually set up a residents' WhatsApp group, in which we provide practical and moral support to each other. Part of this involves encouraging each other to take our daily singular state-sanctioned exercise, to keep spirits up.
When we took our daily singular state-sanctioned exercise yesterday afternoon, every group we saw kept a (very large, more than 2m) distance from each other; one single chap was practising martial arts, some were running, others strolling, some walking dogs, some with small children even sat down on the grass or a log. If people saw someone they knew, they did distant polite waving. Nobody abused anyone else. I saw nobody using the exercise equipment, touching gates/handrails (of course it's possible they were all waiting for me to walk by before gathering in a giant neighbourhood scrum and all licking the playground).