Social distancing is a skill that takes time to perfect. Avoiding catching or spreading Covid-19 means keeping a safe space from other people, not avoiding them. Just because we have to work or do school lessons from home does not force us to be housebound. A healthy immune system to fight off the disease requires moderate exercise. Hong Kong is in a more fortunate position than other cities, where home lockdowns are in place. We do not get fined for being outdoors, as in California, or can only do so if necessary and have filled out a form giving the reason, as in France. If we want exercise for the sake of our mind and body, we do not have to run a marathon on a balcony, as a man in Toulouse did, circling about 6,000 times to notch up the required 42.2 kilometres. We can easily head for country parks and hiking trails, remembering to keep about 1.5 metres from others we meet to avoid moisture droplets from coughing and sneezing. Research shows exercise can affect the body’s immune system. Dancing the salsa and social distancing don’t go together A groundbreaking Hong Kong study published in 2008 of 24,656 Chinese adults who died during an influenza outbreak in the city in 1998 found that people who never or seldom exercised or did so more than five times a week were at higher risk of dying. American researchers have determined that engaging in physical activity past exhaustion or doing so without allowing sufficient time for recovery also increases chances of infection. Working out or playing sport while sick raises the possibility of medical complications. The French runner would not seem to have been making a wise choice in deciding to run a marathon in the midst of a coronavirus outbreak. Confirmed Covid-19 cases among people who visited fitness centres have prompted authorities to temporarily close such places until the threat recedes. While researchers warn against exercising in crowded or enclosed spaces, doing so in locations that are well-ventilated and while keeping away from others is for now still believed to be safe. Mild to moderate physical activity of between 20 and 45 minutes up to three times a week is considered by experts to be ideal. Coupled with social distancing, cleanliness and eating and sleeping well, there is every chance of lessening the risk of infection.