Read on Twitter
The study we all have been waiting for (or at least I): should you keep increased distance (>1.5 m) when running/cycling to prevent getting infected/infecting others with COVID-19?
New research suggests yes (more in thread below)
New research suggests yes (more in thread below)
If someone exhales while walking, running or cycling, most of the microdroplets are entrained in the slipstream behind the runner or cyclist. Another person who runs or cycles just behind this person then moves through that cloud of droplets, potentially getting infected.
The images below show the slipstream for walking at 4km/h and running at 14 km/h. The red dots on the images represent the largest particles, they fall down fastest, but are also considered most contagious
Therefore, the researchers advise to keep a distance of at least 4-5 m behind a person while walking, 10 m when running or cycling slowly and >20 m when cycling fast.
"If you want to overtake someone, it is also recommended to start "pre‐sorting" into a staggered arrangement from a fairly long distance – twenty meters with bicycles, for example, so that you can overtake carefully and at a proper distance by moving in a straight line."
Note that the paper has not yet gone through peer-review!
Another important point is that the researchers did not investigate the effects of cross-wind and assumed calm weather.
Another important point is that the researchers did not investigate the effects of cross-wind and assumed calm weather.
Further, a very important point is that it is currently unknown to what extent the micro‐droplets with the virus still carries an infection risk after evaporation. Nevertheless, it is probably good to keep these suggestions into mind when exercising.
My personal suggestion: when you can't follow the guidelines, try to temporary hold your breath to prevent getting infected, and infecting other people, for example when overtaking someone else
Link to white paper here:
http://www.urbanphysics.net/Social%20Distancing%20v20_White_Paper.pdf
Link to white paper here:
http://www.urbanphysics.net/Social%20Distancing%20v20_White_Paper.pdf
Credits to @BertBlocken and colleagues for performing this study!
