Under normal circumstances I quite often run a 10+ mile route with a supermarket between miles 7-8. I often pause my watch, go in and buy a bag of crisps and can of coke/red bull to power me up for the last few miles of slogging back up hill. Crisps are great for quick release starch and replacement of lost salts through sweat. And the sugar and fluids from the Coke are also great energy replenishment after approaching 2 hours of running and walking.
The key point of the legislation and guidence issued is to reduce (not eradicate) the spread of the virus by close proximity to people. Depending on location, some parks are being prone to overcrowding due to their popularity, population density and lack of range of pleasant personal and public outdoor space so "loitering" was initially strongly discouraged, particularly after mother's day when crowds flocked to tourist honeypots.
Some people do need to rest while exercising- whatever the intensity. I had the experience of being utterly drained in my early pregnancy when it wasn't outwardly visible. I remember struggling to reach a bench on a gentle local walk, feeling completely bemused that a month earlier, I could have jogged that far without issue. Later in pregnancy, my mobility continued to be compromised by SPD which was considerably more obvious until it reached the point of bordering on being housebound.
At present I'm fortunate to have access to local, quiet, uncelebrated countryside to run/ walk in. I've been taking the DCs on some of my running routes. Being small and young, we take food with us because they tire more quickly and need some incentivisation. We've had basic picnics in very quiet, secluded spots because the benefits of the children walking for a couple of hours far outweighs the tiny risks of stopping and being infected in such quiet places.
My family is low risk and it is far healthier for us, body, mind and general immunity to continue going out to quiet places, and shock horror, sit on the occasional bench and take food with us. I'm already facing weight gain in the loss of unstructured activity as it is.
My main issue with crisps and exercise is that they are awkward to transport without crushing them.