I’m not an epidemiologist, but I do study fluids and turbulence.

There is nothing special about the six-foot distance other than maybe a typical ejecta plume from forceful breathing in still air, from an uncovered mouth.

One of the first things a graduate course in turbulence covers is diffusion from turbulent mixing, and the short of it is that on the order of a minute or so, air from across the room will reach any given spot in the same room. So, at some point the six-foot rule is just enough to distance for a sneeze or so, but eventually the ejecta will be dispersed throughout the room.

This video is pretty informative: https://youtube.com/watch?v=vBvFkQizTT4

Outdoors in still air may not change the acute spray of ejecta, but certainly the long-term mixing will be much diminished in a localized volume.

I wouldn’t think that the concentrations from brief, transient outdoor incidence are significant enough to pose a significant risk. Indoors, there has been some “15 minute indoor exposure” rule, so one could try to do an order of magnitude to find an equivalent exposure level from some person breathing hard on you outdoors... but frankly the science won’t be anywhere near converged to such a level of detail before we stop worrying about it. So, the bottom line is that everyone must manage their own risk, in the same way that a pedestrian may have a “right of way,” but being ran over and correct doesn’t do them much good.

The problem with everyone managing their own risk individually is that (as we can see in this thread) everyone's assessment of what the risks are and what precautions make sense are different. We've had responses that vary from "don't get near me" to "you can spit in my mouth."

Where I live there is a county standard: You must carry a mask, and must wear it when exercising outdoors whenever you are not able to maintain 6' of distance. We can debate the scientific merits (and advocate for a better standard), but at least everyone knows what is expected of them and what to expect from others (you can always be stricter than the standard, but cannot ask/expect others to be).

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

My point is slightly more subtle. People should obey the guidelines, but since we can expect a fairly high amount of rule breakers, that has to be considered in one’s personal risk assessment.

For example, the airline industry made a covid “study” flaunting a super low risk “if everyone wears their mask” along with cabin air filtration. Disregarding the likely bias, how many times have we witnessed people ignoring these rules indoors? People with no masks, or masks below their noses in stores or in flights...

^This

The data have no opinions or feelings and since COVID doesn't either (or sense of geography), it's safe to presume these numbers would be replicated in your city.

If you really want COVID, stay home and have your family come over.

This is a very "Bikeforums" or "Lavendar Room" style poster. They come in here to bitch and moan about something (looking for affirmation), and when they don't get affirmed and are presented with the same evidence and regulations we've all seen for half a year they state instead they prefer some other "visualization graphics" that supports them instead. Basically came looking for a fight and is cherry picking the evidence and now is angry because nobody wants to affirm them.

Also, there's some pretty basic math at play here being ignored. If you pass somebody at just 2mph delta.......you're putting 3ft on them per second.

I have NEVER in riding for 4 years and 10000 miles ever encountered alone on the road someone who passes me within a foot or two of my front wheel.

I guarantee it's the classic "objects in mirror" scenario where this poster can't perceive the distance. If it isn't, it's a rare occurrence and somebody didn't have their morning coffee.

If the passing rider gets over after 3 or 4 seconds (like I see around here) they are well over 10 ft away.

Lastly, absolutely nothing has been mentioned about how the original poster didn't realize that THEY can choose to not ride in the slip stream of the rider in front of them! Slip over two feet.

In triathlon or in time trial, after someone has been legally passed...........guess what.......the onus is on YOU to abide by the drafting rules and/or move to the side some distance to not be in the slip steam.


Same in skiing. Person in front of you has the right of way. I love how this person is coming in here all Karen and trying to put the onus on somebody else. You're passed, you're now in charge of safely following!

 

Everyone should get to set their own boundaries and not sure how to protect yours .. can you ride different routes? .

Out of curiosity, has there been a single instance of covid transmission outdoors ? I’m under the impression there hasn’t, but maybe I’m wrong...

I am familiar with the science around COVID, as a physician versed in epidemiology and as a therapeutics developer.
And I generally agree with windschatten’s concerns here, though perhaps getting lost in the emotions and style of this debate—the crux appears to be discomfort when others do not obey social distancing while participating in outdoor sport.

1) Debate aside, everyone must do their part in obeying guidances which include responsible social distancing, wearing masks, and avoiding crowds.
2) Outdoor or sporting activities are not exempt from social distancing principles. While risk of transmission is definitively lower due to virus dispersion and rapid inactivation of virus (in minutes not seconds) in direct sunlight, the risk is non-zero. Those espousing paucity of reported cases from outdoor transmission is mistaking incomplete/poor data ascertainment with evidence of proving the negative. There are definitely cases of COVID from outdoor sporting activities when collected via more complete national registries. For example, additionally, there is not one well-documented case of transmission of SARS-CoV-2 from contact or fomite transmission—this is not evidence to stop washing our hands, but rather fomite transmission can be reasonably ascertained from known science from the totality of virological science.
3) Public health measures cannot be contingent upon how we feel—the game changer for SARS-CoV-2 is that transmission occurs with asymptomatic people.
4) I observe a lot of individual decision-making about risks of infection to one’s self, which is not the central principle in this pandemic—it is what measures we take to reduce risk not only for ourselves but for every subsequent person who might become infected down the road. Most people who contribute to asymptomatic transmission of this virus are not considering the innumerable nameless faces of people who suffered or died from their contributory behavior.
5) These being said, we should all be able to enjoy outdoor sports while respecting others by distancing and wearing masks when nearing people. While inconvenient, we should pull our mask over our face when passing or approaching other people.

Please take care everyone. Wishing you all well.

  

On #2... Presumably the risk of you handling an amazon delivery package and getting covid is non-zero, the risk of you getting attacked by a bear walking to the mailbox is non-zero and the risk of getting covid while in an apartment building via airborn droplets from toilet water is also nonzero

When you say outdoor transmission is non zero ... is it practically likely or non zero like the above?

I struggle because If someone had research to suggest outdoor cycling w others (well, or unwell, tbh) is unsafe I’d stop. But everything I see suggests that it’s not unsafe, it’s just not zero

I watched the Tour de France, Giro, and Vuelta happen. TdF happened with crazy amounts of fans while Covid19 was rising rapidly in France. Not a single rider caught it from the brief seconds they rode by all the fans. Its not hard data, but we have almost 200 riders going through all those fans for seconds at a time who did manage to not get Covid19 through that exposure. It is a faster speed that two riders passing each other but its non zero exposure time outdoors.

As I mentioned in my city indoor pools have been operating from July to December. 4 swimmers per double lane, slower passing speeds than riders passing each other, people resting (generally respectfully at the wall, but sometimes not) everyone breathing very hard. Our city has something like 20 pools, so with some rough math, with 5 lane swims per pool per day, so 1600 swimmers x 180 days that is 288,000 visits including lifeguards on deck. Let's just go with 144,000 visits, people swimming indoors in close quarters (relative to the bike example), and also using change rooms after swimming. On top of this there are club practices, public swims, and aquafit also.

There was zero cases of transmission linked to the pools.

Total cases have been 10,184 out of a population of 1M (so roughly 1 person out of 100 have gotten this so far).

It could just be swimmers in my city are magically not bringing it too the pool, but that seems almost impossible.

So relative to the example given by the OP, I think our pool environment is a lot worse. I swam 600km during this time and no doubt have been exposed numerous times but the question is how much total load am I exposed to. Clearly our head of public health in our city feels this is low risk relative to other things in society. I would think the riding example is far far far lower risk than the pool, so personally I am completely comfortable taking it, I don't think any rider will give me Covid19 out on the open road, and even though I THINK I will not give it to anyone I will respect them and pass wide and as quickly as possible.

We may not have good data on riding outdoors (it is all anedotal like protour riders all over Europe), but we have a relatively good data (at least in my city) on swimming in a closed frequently environment, that is a lot worse than riding outdoors.

John Cobb Cycling Wind Tunnel - YouTube

You cannot claim “zero cases”—the epidemiological methods are not comprehensive enough to claim this.

I fail to see the objective of your communication here, Dev.
As mentioned above, I have agreed most sporting activity generally carry low risk, and I wholeheartedly support continuation of sporting activities though we still should obey guidance and practice and respect precautions.
We post in a public forum to share our views knowing there may be broader impact of these opinions. If your point is to waive public health measures for sporting activities, I categorically disagree with that perspective and communication objective as irresponsible.

If your regional public health guidance has weighed benefit:risk to open swimming pools, that is terrific. Chlorinated water quickly inactivates virus, but probably should take whatever reasonable precautions in changing rooms, etc.

Good luck to you, and happy new year.

What I was trying to share is our public health has records from half a year of operating indoor pools. Chlorine does not kill virus in the air so that virus is floating around above the water as we pass thru it and breath it. What I just shared is how many swims happened in an environment much worse than the cycling example.

Nothing is zero risk the question is what we do while minimizing risk to all around us and ourselves. I shared a higher risk activity than the low risk cycling example where our city has collected records has all the phone numbers and contact tracing is going on.

So people can decide how comfortable they want to feel with this additional info. I would suspect many locations in the US are not operating this degree of indoor pools all centrally coordinated as in Canadian cities with public health oversight of these publicly run facilities. So increasingly we have more info here on this use case, more coordinated action due to the facilities being publicly run, with public health oversight. So there is accountability since it's not being run for profit. If there is anything bad happening the hammer comes down quickly and all facilities get shut. In that context it has been one of the lower risk activities in society. And in that context cycling outdoors should be safer given the speeds, volume of air, and overlap time between riders.

So hopefully people can feel less worried. For sure there is never no risk so let's put this in the context of relative risk so people feel less scared about Covid19 from cycling. There should be many things we do daily both covid19 spread related or personal risk related that are far more dangerous to us and society.

Just to add, its not me claiming no cases traceable to pool usage at our city. The city officials have a fairly rigoorous protocol that they need to conform to and have said they don't have any cases spread through their system. Of course this is the "that we are aware of", but Canada wide Swim Canada aggregated up everything from across the country, and published a report articulating the same. At this point there are enough visits to at least know that its rare, bordering on zero (I say bordering on zero, because they had zero reports and sample size is quite large....it may have happened, but quite infrequent that from a risk angle each of us can choose to feel comfortable or not). We have all kinds of reports from schools, workplaces, restaurants, bars, church gatherings, parties, etc etc, but pool looks pretty decent. At least there is some semblance of data from pools. Cycling we don't have anything really that good but it should be better than indoor swimming. If we can't agree on that, that's fine we agree to disagree.

Coming back and thanking everybody for their thoughtful (particularly J Kae), less thoughtful (anecdotes) and sometimes hostile/aggressive/hare brain responses.

Cycling has changed with COVID.
More ride, and many seem to think of it as an outlet where everything goes. An outlet that’s immune to COVID (as responses show) and other social courtesy and common sense (traffic rules).
I know, Oldtimer talk.

My original post clearly outlined my concerns:
Pass within 1-3 ft for several seconds (5-10), looking/breathing at another rider without wearing a mask and while often not holding the line.

Again, the only real data I have seen indicate a possible significant risk and we all know a/symptomatic spreaders and vulnerable individuals ride.
For that reason many areas have guidelines for riding outside.

On the point of ‘riding as you please’:

In a Zoom call the other day I recognized/confirmed a possible local IT contractors’ reckless riding we observed
a couple days back (no mask, wiggling by slowly within inches and proceeding to run our red light).
He didn’t get the contract.
.

For the part in your post in bold, when you say "possible significant risk" consider making an ordered risks of chance of dying from various actions on one side of the spectrum if we put high probability items like cancer, heart attacks, traffic accidents, on the other side, low probability items like dying in a plane crash, getting hit by a bolt of lightening in your house, from gunshot while being unlucky enough to be in a bank during a heist etc etc and somewhere along the spectrum, from Covid19 specifically while cycling with X passes adding up to Y seconds per hour of cycling.

In going through this exercise, people can decide where Covid19 while cycling fits and then they can decide for themselves their personal risk and also if they are being bad members of society for cycling and spreading this disease vs being bad members of society for getting in a car and potentially killing someone in an accident.

I don't know what the gauge is for "possible significant risk" but at least if we put quantified data down, everyone can decide what that may mean in some kind of a statistical way that framed with real numbers. If the probability is higher than bolt of lightening or less for us personally dying we can make a call on personal risk tolerance.

Where I live public health authorities are encouraging outdoor activity and where we have to pass inside 6 feet, we are told to make the pass quickly. Almost no one wears a mask for these types of scenarios (I am all for wearing masks indoors or for extended outdoor contact). I don't know what types of stats they have to allow us to do this as we are in a lockdown, where most things are not allowed. But outdoor exercise is permitted and encouraged right.

Our public health authorities may be complete idiots or really smart, but for now they have completely erred on the side of ultra caution and only allowed things from "normal life" sparingly. Solo outdoor activities have never been curbed here when everything else has been. So this is not me coming up with something. Lots of doctors, scientists and public officials where I live are encouraging us to get out and exercise. I would imagine they have weighed all the risks to individuals and the entire society and given it the green light. I don't know where you live and rather than 1/100 people having contracting Covid19 (as is the case where I live) it may be different where you live so maybe more caution is needed there on the probability/risk spectrum.

I think you may not need to be as worried as you make out to be on this thread.

I am still struggling with the communication objective.
Though more importantly, I believe we are (and apparently always have been) agreeing on key points—at least I hope.
- We should continue to joyfully participate in sporting activities, which in most cases are lower risk and improves health and well-being. The benefit:risk is very positive.
- We must still adhere to public health guidances, including social distancing measures, especially amid this global surge in COVID-19 before vaccines become broadly available.
- Many sports activities carry implicitly lower risk of transmission, but do NOT waive us from public health recommendations/guidance and reasonable social distancing measures.

The following points are rather trivial if we agree on the above, but I have concerns in this thread about:
- Ignoring or minimizing the concerns of the OP, who admits being an older aged higher risk demographic, for having concerns about fellow cyclists not respecting social distancing. For a cycling and triathlon community this is disheartening to observe.
- Inadequate precision around data, or lack thereof, and its implications. I know something of clinical data ascertainment, quality, integrity, and interpretation, and I am not in agreement with your interpretation of exposure-adjusted risk. And contact tracing is a highly labor-intensive process, and most jurisdictions, including major cities in US and Canada, have declared contract tracing resources overwhelmed and incomplete by last October amid this surge. Many Western cultures also do not wish to participate in voluntary contract tracing or thorough observational research—for example, almost half of Canadians declined to participate by survey. Again, while lower risk of transmission liberates us to embark on many athletic activities, it should not allow us to neglect public health measures.
- While many hospital systems have saturated their ICU/ ventilator capacities, this is NOT the time to communicate complacency around public health measures or indignant attitudes towards people who are concerned with respecting social distance. Additionally, I know first hand the COVID pandemic impacts risks outside of direct SARS-CoV-2 infection. Global clinical outcomes trials are in real time identifying reduced hospitalizations of all cause because of patient fears of coming to hospitals—the impact is less adequate management of chronic disorders, increased suffering, and many more people dying at home from various acute and chronic disorders.

You want to change other people's behavior while they cycle outside near you, right?

Do your own science. Next ride, why don't you wear a white T-Shirt over your kit and mark on it with a sharpie, "At risk from covid, please stay 6ft away." Record the number of people that pass you and how many come within 6 feet. Try different messages and colors and determine what is most effective for your you.

I was hiking on busy trail in Nashville a week ago. When passing, almost always I, or they, stepped to side to allow six feet for passing. Only about 1/4 wore masks or put on masks when approaching. If passer was wearing a mask, I put on a mask as courtesy to them even if six feet away. Sometimes I put on my mask first and then the passers did in response.

Some people you cannot make courteous, but I think some number will be responsive if you wear your concerns on your back.

I rode 50 miles in Birmingham on a cool morning yesterday and didn't see a single other rider (usually I'd see 10-20), so I don't have experience dealing with many others on road.

Hearing your concerns, I'll be more attentive to giving space when I pass.

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It doesn't really matter what Phil is saying, the music of his voice is the appropriate soundtrack for a bicycle race. HTupolev

I think we generally agree but the nuance here is around zero risk vs low risk and following public health rules (wherever we live)

Just to be clear, over here, swimming 4 per lane was supported by publiic health until everything indoors including offices have been shut during this current lockdown that started on 26 Dec.

Where I am, Outdoor solo sports are supported by public health with no masks needed as long as people quickly pass one another when the path is narrow. Where I live this has been supported and permitted by public health and never been limited since day1 (outdoor group activities have been limited). This is why I was giving these examples that "at least where I live" this is permitted and falls in the category of keeping our guard up. Taking our guard down, would be going to an illegal indoor gathering, a now closed down spinning studio, going to indoor restarants and bars, visiting family members (we cannot visit ANYONE and can only have contact with the people we live with).

So I was providing info that is supported by public health where I live. Outdoor Cycling or skiing, or running or walking outdoors and quickly passing others (even if with no mask) does not fall into the category of letting our guard down (where I live). It is approved.

These discussions are difficult because people share what is allowed where they live and get told to shut up, and on the flip side people tell others how to behave based on rules in their place that are not in place in other areas. It can easily go downhill from there. Providing people with information from all over the world allows for people to see what is going on where. This may or may not be applicable to where they live but at least they get exposure to what may or may not be working. Telling people in another jurisdiction how to behave based on the rules and situation in your own however, goes nowhere. If somone from Toronto tells someone in Mumbai India what to do and how to distance where they are shrinking their curve doing whatever they are doing in Mumbai but applying rules and norms from Toronto (where everythig is explodiing) is going to go nowhere.

So I am just saying the goal is to information share. If it helps others feel more comfortable doing low risk things or deters them from doing high risk things, then that's productive discussion. If not we don't need a forum, just read the website of our local public health.

Not much to add.

Part of my job is risk assessment, evaluation and mitigation during project management.

In that speak, I experience and see an absolute failure from a significant part of our athletic community to acknowledge the basic risk, and to agree on a basic vision and mission statement for its simple and easy mitigation.

Not even to speak of being positive catalysts or role models in that regard.

But that’s our society right now, and it is foolish to expect more from this community.
But advocacy and raising awareness isn’t something I would want to give up on.

Also you refer to contact tracing having its limits but on the flip side the onus would be on you or public health or whoever is saying outdoor exercise is spreading this virus inclusive of moments when participants pass one another outdoors to prove that it is. Not to shame others for doing the activities in the remote case that maybe there is some spread.

Right now we can't point to a single case around the world where this has been definitively shown (or even with a high correlation).

Literally no disease we know of has been spread this way in outdoor activity. Maybe this disease unique so let's go get the hard proof. In the mean time manage risks and respect one another. This includes respecting others who are not hurting us even though we think there may be a remote chance they are. If they are hurting us, by all means we should ask them to change behaviour.

When we go to the pool, walk on the trail, go to the mailbox there is always a chance someone spreads something. But the outrage some people can also be tuned to the venue and risk. At most of our pools people are respectful that I'd they finish hard 100 fly to not hyperventilate at the wall close to others. We turn the other way or walk 6 feet up the lane to give people space. If someone behaves like a jackass we say something but if you come to the pool a someone makes a pass because they swim faster we have to let that go. It's so ethi f that will happen at the pool. If we walk or jog on a trail we will passed and be passed. If we bike we may be passed.

Let's all get along and save the combat for when someone is hurting others. If they are being ultra low risk to others I prefer to let them enjoy themselves .

"Rarely am I able to pull up my mask in time....and any convo is a higher risk"

It seems like you are putting them at risk too?

When people that wear a mask while riding pass you and see yours is down, do you think they feel disrespected by you not wearing the mask?

I wear a mask while running in the treadmill at the gym, not for myself but for others and because I have to. I have no expectations of other people doing what I want, I am happier that way.

Just my two cents.

I don't see the failure to acknowledge risk. The assessment of risk for contracting Covid while exercising is subjective and not easy to come up with an accurate number. Most on this thread have made their own risk assessment and it appears lower than yours. Once you've made an assessment of risk each person has their own level of risk tolerance. Your tolerance for risk appears very low and there's nothing wrong with that but you also need to accept that others may have a higher tolerance for risk.

Whether someone passes you unmasked on a bike at 3 or 6 feet makes little difference to the risk. Both cases are very low but non-zero. If you are unwilling to accept someone passing you on a bike at under 3', one could argue that you shouldn't spend any time indoors regardless of whether everyone is wearing masks as the risk is also non-zero and likely much higher than the bike pass.

Adhering to public health guidelines for a particular activity does not eliminate risk. Air travel is allowed (but not recommended) in North America but is clearly a far higher risk activity than exercising outdoors.

Exactly. Too many people want to live in a world with nothing but people that agree with them. This pandemic has really forced our personal truth bubbles to the fore. You have anti-science folks on both sides: people who think Covid's all a hoax dreamed up by the "damned libruls" and those who think the only acceptable risk level requires us all to be locked in hermetic clear plastic hamster balls until they say we can come out. Both are irritating and both are going to be a problem as we try to return to normal.

I ride a lot on the (huge and largely vacant) local MUP network. I ride mostly alone or with one or two other people I trust. I'd say I rarely come within 30 feet of another person, let alone 6 feet. Still, I routinely see people who RUN off the trail when I get within a hundred feet of them, quickly pull on a mask and turn their back to me. Just a complete overreaction. Sorry folks, if you're that terrified you shouldn't be on a MUP, or even outside.

Using terms like “combat”, “shame” and “outrage” while employing hyperbolic arguments and confrontational language does not convey intentions of “getting along” in a respectful way. Please consider this.

With regard to maintaining reasonable social distance while engaging in outdoor activities, your mandate for requiring hard, definitive proof of transmission under specific scenarios to defend public health policies during a surge in a global pandemic is pretty unreasonable. Public health and safety does not work that way. The epidemiological tools, as I have stated, are imperfect, and much requires reasonable scientific deduction with what is known in totality about infectious diseases. Saturation of critical health care resources is real, and social distancing as a public health measure against a highly contagious airborne infectious disease is credible, and can be reasonably done without significant impairment on one’s ability to participate in most outdoor sports activities. The hope that people can be respectful to each other and obey public health directives should transcend your personal opinions or qualitative perceptions of risk.

I have worked with Health Canada before, and they have historically been science-based and reasonable, and I am not sure whether the exact point of view you are espousing is their intent. And the “combat” you describe is partially synthesized. The OP has described a higher exposure scenario of denser cyclists where s/he lives, and experiencing cyclists deliberately making no attempt at social distancing. You are creating false equivalence with and transference of that situation with your personal and regionally accepted practices that strike me as variations of social distancing, ie, quick passes while making every behavioral attempt to lower exposure by distance or time—the time-adjusted exposure of such passes made with intent to obey the principles of reasonable social distancing. This is not the same as people participating in outdoor activities with no recognition or respect for reasonable social distancing measures.

I hope we can still land on our common agreements:
- A full-throated endorsement of responsible outdoor sports activities as being markedly positive for benefit:risk in promoting well-being and health.
- Adhering to public health directives/ guidances including responsible social distancing. And being respectful to each other, even in disagreement, amid this pandemic.

I will stop here, since this appears to be an activity of diminishing gains.

That's the perfect summary and place to stop! I don't think there's a ton of substantive disagreement in this thread. Just a lot of sophistry to try to win narrow internet arguments.