Why you can't run and ride a bike next to other people during quarantine

Why jogging and cycling during a pandemic is dangerous

The key rule of quarantine measures designed to slow the spread of COVID-19 is social distancing.

The most reputable medical organizations in the world strongly recommend staying at home in order to limit contact with other people. If you cannot do without contacts, you need to keep a distance of at least 1 m Q&A on coronaviruses (COVID-19) (according to the American Centers for Disease Control and Prevention - at least 1.8 m How COVID-19 Spreads) from others.

It is assumed that at such a distance, the smallest droplets of saliva that another, possibly infected person, secretes when talking, coughing, breathing will not reach you. And you, in turn, will not share your own.

Social distancing is a reliable way of protection for people who stand indoors or outdoors in calm weather. But if the person is moving, the safe distance increases significantly.

Bert Bloken professor of aerodynamics

When you cough or just breathe heavily while jogging, aerosol drops of your saliva remain in the air. The person running after you has to run through this cloud of drops Belgisch onderzoek: fietsen, joggen of wandelen doe je best niet achter elkaar in tijden van corona.

And this infected cloud is the longer, the higher the speed of the athlete.

What is the safe distance when walking, running and cycling

Scientists from the Catholic University of Leuven (Belgium) and the Technical University of Eindhoven (Netherlands) conducted a study in which they studied how far a trail of droplets of saliva stretches behind a moving athlete. This work, so far in the form of a preliminary report (the so-called preprint), was posted by Towards aerodynamically equivalent COVID19 1.5 m social distancing for walking and running on the Web by one of the authors - Professor of Aerodynamics Bert Bloken.

This is what the aerosol cloud that the runner leaves behind. Large and heavy droplets of saliva are marked in red - they settle faster than others. But the lighter ones (yellow, green, blue) remain in the air long enough - this time is enough to infect other people, even if they stay away from the athlete.

The researchers analyzed how saliva particles spread from a fast-paced, running person or cyclist. And they found out that the safe distance for two people who are moving one after another should be increased:

when walking - up to 4–5 m;
with slow running or slow cycling - up to 10 m;
when running fast or driving fast - up to 20 m.

It is quite difficult to maintain such distances while jogging or cycling, because people have different rates of movement. And overtaking a sluggish athlete, you run the risk of catching an infection. The only way to reduce the risk is to lay a large arc when overtaking. It is important that you yourself do not fall into the aerosol trail of a runner or cyclist, and the other person does not end up in a cloud of microparticles of your saliva when you get ahead of him.

An important point: the results of the study are not yet definitive. This work must be reviewed and published in scientific journals.

Therefore, the final values of the safe distance may change.

Now only one thing is clear. You can run and ride a bike. But only if there are no other people near you, at a distance of up to 20 m. If you cannot guarantee this distance, it is better to refrain from such a sport so as not to become another link in the spread of the coronavirus.