If you live in the UK you will have been told that the only reasons to go outside are to go shopping for food, to exercise, or to travel to work if your work cannot be done at home during the coronavirus outbreak.

The simple fact that the government is allowing people to go out and exercise once a day indicates that it is absolutely vital to recovering from COVID-19.  What they have failed to do is specify what the nature of that exercise should look like, and the duration of it.  This is covered in the below BBC article:

https://www.bbc.co.uk/news/uk-51506729

Clearly, to me, the issue here is exposure.  Because of the importance of social distancing the deciding factor when considering exercising outside is time.  Both duration of exercise and relative footfall numbers play a considerable factor in these decisions. 

If you are in a more rural environment then in the course of an hour long run you might encounter ten people at a peak period.  Of those ten people none of them would come within the two metre zone, five would be within five metres and five would be within ten metres.  The risk of exposure and contamination is therefore low.   

But if you live in a built up area where your only option is to run in a park at peak time you could easily encounter one hundred people during your hour long run.  Of those one hundred people ten could come within the two metre zone, forty within five metres and fifty within ten metres.  The risk of exposure and contamination is therefore high.

Running at a less peak time, away from the parks and along the streets, might reduce the numbers significantly.  Outside my flat, for instance, at around 9pm and later there is barely anyone outside.  Running at this time I would imagine you would see less than twenty people in an hour and it is more than possible to maintain the two metre distancing, which would dramatically lower the risk of exposure and contamination.

So, in order to be socially responsible and to avoid aiding in the spread of COVID-19 we must consider the timing of when we choose to exercise, as well as the duration.  This is, I believe, the fundamental reason why the government haven’t set a duration time for exercise, because the level of footfall along your exercise route will impact your risk, and therefore impact the duration that is sensible.  And clearly, undertaking all other forms of exercise which can be done at home should be done at home.