The gymnasia are closed, as are the sports centres and swimming pools. People are taking exercise in the parks: they are walking, running, cycling, skipping, lifting weights, boxing, dancing, stretching, and playing football and cricket. It is good to see children and adults – of all ages and sizes – trying to keep healthy, in body and mind, by working their muscles and their lungs. The spring and summer months, even in London, are conducive of outdoor activity most days.