Much of the tension depends very much on where you live. If it's in the suburbs of an average city, maybe on a housing estate (of all degrees of wealth), it could be several miles of walking to get to what you might call 'green space'. Many city parks are not much more than a square of grass with some swings, especially in London. So folks are literally restricted to walking around their urban neighbourhood for exercise - hardly stimulating if most of that is concrete or brick canyons. If the neighbourhood is not that safe already, they may be even less inclined - though I'd be interested to hear how the gang situation is faring under lockdown.
Living where I do in Sheffield I've got access to several large parks and large areas of woodland within 15 mins walk of my home, so it's not too bad really. But I've noticed a huge increase in visitors to places I'd normally expect to be deserted - which is probably a good thing, if a little disconcerting. Many are clearly unfamiliar with the location (and the territory - some walk as though they're half-expecting something to drop onto their heads from a tree), and I've even been asked the way to places, but generally, if they're discovering their local wilderness (and walking to it) whilst maintaining social distancing (not that hard in the woods), it has to be better than sitting indoors watching TV and eating crap.
If obesity is a major risk factor for Covid-19, and it's certainly looking that way, then folks need to get exercising and cut down on eating, as it's a major issue here, and even more so in the US. The receptionist at my local GP surgery is so large you can hear her breathing (gasping) on the other side of the reception room, and it's not small.
