Epidemiologist Rides a Bike

By now, some of you may have heard of the Dutch/Belgian study whose authors recommended that fast runners maintain at least 10 m distance and fast cyclists maintain at least 20 m distance from others in their “slipstream”. It received a lot of media attention, enough that runners and cyclists felt a bit demonized.

The researchers used existing wind tunnel measurements to computer simulate how far droplets traveled after being coughed, sneezed or exhaled by a fast moving person.

There were many limitations to this study. Mainly, the study was about droplets, not infectious particles, and none of the authors were medically trained. Many medical experts have responded that the study in no way addresses the risk of spreading infection. There are many more factors to consider. Droplets disperse much differently outside than inside and are subject to the effects of temperature, humidity and wind currents; all can significantly reduce or eliminate the ability of the virus to reach and/or infect another person. Finally, the work has not been peer-reviewed, something we require in the scientific world for anyone to make any serious claim about the results of anything. Anything less than that is just conjecture.

As SRCC’s resident doctor of epidemiology, I still strongly recommend that you ride solo or only with those with whom you cohabit. If for some reason you simply must ride with others, exercise extreme caution. Only ride with one or two people whom you’ve frequently ridden with before in order to reduce the risk of accidents. This will also make it easier to ride side-by-side or stagger. Choose quiet roads as they lower your chance of car/bike incidents. Stay out the hospitals as much as you can.

Keeping the number in your group low (one, two or three max) directly lowers the risk of transmission. It also helps avoid having to ride in someone’s slipstream. And riding in larger groups may not only be risky, it sends the wrong message to the rest of the community about cyclists.

So how far away is good enough to be safe and beyond the reception of someone’s virulent personal droplets? Scientifically, we simply don’t know. Obviously, the further apart the better, and certainly no closer than 2 metres. For a given distance, the above-referenced study indicates that side-by-side is less likely to lead to transmission than riding single file. No shit Sherlock.

Never forget why we’re doing this. We’re not doing this so we don’t get sick, we do this so we don’t get other people sick. And step one in that is: don’t get sick.

These days everyone needs to do their part. And when we’re seen, we need to be seen doing our part. Simply, group riding is verboten. Don’t be a douche, doctor’s orders.

Wash, rinse, repeat.


COVID-19 Cycling Advisory

These are difficult times and we need to be good, responsible members of our communities. Everyone is finding ways to cope. Stress relief is important and healthy. We love cycling, that’s why we’re club members. Can we ride our bikes during this? As long as you are not showing COVID-19 symptoms and have not been exposed to someone who is infected with coronavirus or has recently traveled, it is probably helpful for your mental well-being (and your immune system) to get out for a ride. Keep riding your bike, indoors and out. But be smart and safe about it and much safer than usual. You really don’t want to end up in the hospital right now, for everyone’s sake. Here’s some guidelines from one of your board member and professor of epidemiology, Dr. Meg Thorburn (how many cycling club’s have one of those?(!)). She recommends the following:                     

Do not ride outside if you have a fever, dry cough, fatigue or have returned from recent travel unless you have successfully completed the mandatory 14 day self-isolation with no signs of the previously mentioned symptoms.

Do not group ride.

Only ride alone or with household members that you are in regular contact with.

Stay away from busy public spaces.

Stay at least two metres away from anyone you meet on your ride.


The disease is spread through respiratory droplets either directly or indirectly, in the air or from surfaces in which the droplets have landed. So far, we know that this disease is more contagious and more deadly than a regular flu. But we don’t know how long this virus can survive on open surfaces. Wash your hands after touching public surfaces. Soap and alcohol (hand sanitizer) destroys the virus’s protective shell. 


The best plan for riding right now is to go out and ride solo and enjoy the outdoors, in non-crowded areas. Choose a time of day to ride when you know your route will be less crowded with people and traffic.  Ride even more cautiously than usual – this is really not the time for an emergency room visit!

And very importantly, if you are sick or at risk of spreading the virus, do not go outside – self isolate.

For a really good explanation of COVID- 19 watch this short video – The Corona Virus Explained & What You Should Do

Looking forward to seeing and riding with you in more normal times.