Oof, TCM was going to be my fall Marathon this year, but a scheduling conflict had me switching to the Omaha Marathon last weekend.... dodged a bullet here.

My hottest race was the Des Moines 70.3 in 2021 - I drank as much as I could and got ice whenever I could - I was still overheating and dehydrated towards the end - and that was with some specific heat training as part of my preparation. When I last did the TCM in 2018 it was about ~ 45 deg at the start. Starting nearly 25 deg warmer is a completely different race. I probably would have attempted if allowed but I do see the massive risk for the 4+hours crowd.

edit: this guy on reddit had a pretty good take as to why it was canceled

What races do you organize?

Maybe instead of canceling they could have changed it to an Ironman race and people could have chosen to skip the swim and bike and just do the run….from a person that did Louisville:-)

Maybe, just maybe, there's some sort of balance to be found between "toughness" and safety concerns. We (rightfully) get threads on here instantly when someone dies during an Ironman. Running a marathon flat-out is different from a 70.3/140.6 run. The intensity is different. If they didn't cancel, they probably would have had a negative headline about something happening to one or more of their runners so they made the tough choice to cancel. I've done this marathon. It's a great race. People will go back. It's right that climate change is affecting races. Bigger races should try to push back a few weeks. Idk why this race and Chicago are still in early October. I can promise folks that the faster runners are ok with not wasting their marathon builds. They can go to Indy in a month & get a time that shows off their fitness.

It’s all relative as you said. I doubt many people had 85-90 degrees in Minneapolis/St. Paul on October 1st on their bingo card.

I have spent the last 20 years in Texas or Florida. I run all summer long in heat indexes of 105+. 85 degrees is nothing to me but it’s all relative. I’m acclimated to much worse. Flip side is that anything under 60 degrees is freezing cold to me. I’d much rather run in 85 than 55.

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Favorite Gear: Dimond | Cadex | Desoto Sport | Hoka One One

I'm thinking the race organizers were not prepared for these temps in October.

My first marathon was in northern Vermont at the end of May (Vermont City Marathon in Burlington) in 2011. That year it was in the mid 80sF and very humid. There were black flag warnings on the second half of the run. I actually had a great run that day but it was hot. Very toasty and the sun and humidity were a beast. I was also quite a bit younger. But there were a lot of runners who were not ready for this heat having trained all winter and spring in Vermont. We get snow in April. A friend ended up in the hospital and luckily was OK. It was a very rough day for a lot of people out there.

I can also understand the frustration of the runners who expected to run a marathon. I would have been deeply disappointed too. With our rapidly changing climate and unpredictable weather patterns, RDs need to be prepared for all types of weather including heat and stocking aid station accordingly. Recently 70.3 racers were experiencing cold and some hypothermia at Jones Beach, NY. Next year it could be 90F on race day (probably will since I'm signed up). It's a real crap shoot with weather these days. Maybe it always has been but more so now.

I will say that mid to high 80sF and humidity will be the reality for a 112 bike ride and marathon in Kona less than 2 weeks.

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Death is easy....peaceful. Life is harder.

69deg wet bulb temp for a Black Flag seems incredibly conservative. By definition the wet bulb temp must be between the air temp and the dew point. You could have 72 deg air temp and 68 deg dew point and have to cancel the race. In eastern US you're unlikely to get below that for half the year.

doesn't it really boil down to the ability of the race medical staff put in place to handle the expected numbers of participants that will have issues during the event, and if statistically, a certain temperature will produce medical issues that will overwhelm the medical staff, the plug needs to be pulled?

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"one eye doubles my eyesight, so things don't look half bad" John Hiatt

Read the study i linked to.

In 2007, when it did not get as hot as yesterday, there were enough medical emergencies from the race to cause 6 local hospitals to change their status to change to “divert” status. That includes over 70 ambulance transports from the course….

They're talking about start temperatures, not the temperature during the bulk of the race. The LA marathon typically has cool temperatures. Average Los Angelese temperatures in March are are 70F (high) / 52F (low). LA typically starts nearly chilly, then heats into the 70s. That's very different from *starting* in the 70's and ending in the 90's.

I read through it and I understand their conclusion. Marked increase in adverse outcomes above 69deg wet bulb. I don't question that.

My hang up is that it's not practical. 69deg wet bulb is a very common, in some places ubiquitous weather condition. In the northeast US where I am that precludes races from May to October.

It's a risk/reward balance, and it seems like the conclusion of this study is very very far on the risk averse side.

But that's pretty much in agreement with the Northeast US marathon calendar, right? Not much in JJA up here (or DJFM) ... September and May are risky for heat you go further south, big city ones are pretty much all in narrow fall-spring windows that move north as the spring progresses, and back south as the fall passes by.

i remember running big sur several years ago and there was record heat. post race i walked into my girlfriend's apt that afternoon and it was over 90 degrees in palo alto. the general consensus amongst most of the runners at the finish that year was the heat massively sucked the life out of the race. there was a death and many DNFs. i can see both sides of this argument. I knew to slow it way down because it was hotter than normal but witnessed lots of good runners walking after mile 20.

Super useful info, thanks for sharing, including the study! That makes sense that the thresholds are wildly different for marathon racing vs. military physical exertion, but I would not have expected by 20 C!

I imagine some of the Twin Cities participants would have appreciated seeing the race-specific threshold information, as well as the data that substantiated the cancellation decision. The WBGT seems like it was very close to the 69 F threshold that morning, and exceedance would have likely depended on the exact time the "start" conditions were taken, and what weather station was used.

I ran the Scranton ("Steamtown") Marathon in 2017 -- start conditions at the nearest airport were temp = 73, dewpoint = 70 (WBGT clearly over 69 whether in sun or shade!). It was certainly one of the most unpleasant experiences of my life. In hindsight it would not have been at all crazy for the organizers to cancel due to weather...

I really like the study write up. But all of the recommendations are based on the starting time WBGT (note that WBGT is not wet bulb temperature). I'm sure someone could be clever and come up with a good way to predict WBGT and mix that with percentage of the field still on the course. But the wet bulb temperature at the race start was 64.0. The wet bulb globe temperature was a little higher at 66.0. There is a calculator here: https://www.osha.gov/...sure/wbgt-calculator. In the report the temperatures they lay out for warning vs cancelling is higher than that.

But I think that brings up the next topic mentioned in the paper about the ability of the local municipality to handle the additional load. It looks pretty clear that they were going to get more people than normal and if the weather continued to break for the worse then they would be solidly in the caution area by noon.

They probably made the right call. But it is difficult to determine if it is because they read the report guidelines incorrectly about the WBGT timing or if they were being sensitive to the local emergency services.

Just for perspective, the WBGT at Kona last year around 2pm (when a lot of people are starting their run) was 86 and last year wasn't that bad. It helps that every participant knew what it was going to be like.

:P

 I was born and raised in Minnesota and have lived here for most of my adult life. I have been a serious endurance athlete for 25 hours. Furthermore, I am a medical doctor. Ironically, I was on call yesterday and so had to get out early before work for what turned out to be beautiful weather for a run. I believe the cancellation was a serious error in judgement, and I would be quite interested to hear the rationale from the medical professionals who were undoubtedly involved in the decision to cancel the race. The question that must be asked is, how much greater risk than normal do the predicted temperatures place on the most vulnerable athletes in the event.

1. Lets suppose that the 5-6 hour crowd will be finishing in the heat of the day at 2 p.m. The temperature at this time was indeed hot, around 90 degrees with some humidity. However, a 6 hour marathon pace is 13:43 minutes per mile. This is essentially a brisk walk. The amount of work (Watts) that is required to achieve this pace is FAR less then that of the runners who are going sub 3 and faster. It is actually the faster athletes who are much more at risk for heat stroke, as they are generating substantially more heat/second through their efforts. I would argue that the 6 hour crowd could have maintained their usual pace in that weather without any significant slowing. After all, the weather in MN has been quite hot all summer, which is when the bulk of training for this marathon was done.

2. "Heat stroke" is very ambiguous waste basket term. In fact, serious heat related illness resulting in endangerment to life is very uncommon in young to middle aged healthy individuals and only seen with any frequency in the frail elderly/very sick populations. They reason for this is the body has a robust system referred to as the "central governor". When you go for a run in seriously hot conditions, your body responds by elevating heart rate, sweat rate, perceived exertion which results in the central governor slowing your pace to keep your body from overheating. If you ignore the signs to slow down and/or don't take in fluids, your body shuts itself down by cramping and your brain shuts down by developing headaches, nausea and dizziness. Permanent brain damage essentially never occurs, and I say this with the authority of a neuroradiologist, ie someone who looks at more brain MRI's and CT's than any other type of physician. I think heat in and of itself is very overblown as a danger to athletes or even recreational types. It is much more dangerous to the elderly and very sick, who simply have no place signing up for a marathon in the first place. In a lot of reported heat related deaths, the underlying cause was a cardiac problem. It is true that overheating can exacerbate cardiac issues, but in many cases there is no way to say if the person would have died on a cooler day. Triathlon is actually the perfect example of this, as cardiac deaths almost always happen in the first part of the race, ie the swim where overheating is not the problem.

Lol...have to ask: are you trolling?

Have you ever thought that maybe this is the reason why here in Southern Ontario our marathons are in either May or Oct-Nov. The Houston, LA, Miami marathons take place in Jan-March, Boston is in April. Chicago in Oct.

https://dumbrunner.com/...o-hard-ass-old-timer

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"What's your claim?" - Ben Gravy
"Your best work is the work you're excited about" - Rick Rubin

I just read through that "study". It is very flawed. Limited data, way too many assumptions and does not account for increased acclimatization of northern latitudes from global warning over the past 10 years among other issues. Having read thousands of papers over the years, the one thing I can say with certainty is that you can come to almost any conclusion you would like if you frame the data in a certain way. I probably would not make a good medical director for a mass participation event because I am not in the "avert risk at all costs" camp, rather I believe that every thing we do in life has inherent risks. A marathon run in high 60s to mid 80s for the vast majority of participants seems like an acceptable risk. And for those who don't feel like they can finish in healthy manner, take personal responsibility and don't start the race.

This is the only race I have done where the gear bags had to be turned in at the expo and not on race morning. Picking them up at TCM offices M-F this week isn't an option for those of us from out of state.

Not sure why the 10 mile was cancelled as even the slowest of the runners would have finished by 10 AM. Easily in excess of 1,000 runners still running from US Bank Stadium to the Capital (without water, aid stations or porta potty's).

What those who were in the decision seat (which is none of us) had to deal with is ensuring that they didn't have a news headlines with death, heat, and Twin Cities Marathon 2023 in the title. A quick Google search for "marathon death heat" found these links:

https://bleacherreport.com/...d-amid-heat-concerns

https://www.runnersworld.com/...dence-half-marathon/

https://www.mirror.co.uk/...denly-drops-29461756

https://www.foxnews.com/...-scores-hospitalized

https://www.accuweather.com/...hon-on-record/349726

https://www.standard.co.uk/...rheated-9696171.html

https://mainichi.jp/.../p2a/00m/0na/006000c


It's not common, but it happens. I am imagining that these race organizers decided that it wouldn't happen at their race. Many on this message board are by definition outside of the bell curve of athletes (and humans in general) and are likely to have a different risk tolerance perspective.


Also the radiologist should know that "clinical correlation is required"....Data can't be taken in isolation. The RD had to think of managing safety for 25K+ participants and all the potential complications of the weather. Maybe it would have been fine, but if they ran the race and someone died, the race directors/race physicians would have had to own that decision and its consequences also. Right or wrong, it's a tough call, but I respect their willingness to make it.

So their flags don't align with actual WBGT or any DoD Standard I've used. DoD is effectively WBGT but there are things that you have to add to do training. But 69F is not black flag and not close. They used language that aligns with government safety models and then changed the definitions. Seems really dumb.

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Washed up footy player turned Triathlete.

Well, the best clinical correlation that I can think of is what the actual runners signed up for the race ended up doing. Thousands went out and ran the course on their own with their race bibs on that very morning in what could best be described as form of protesting with their feet. I don't doubt that the job of a race director is an unenviable one. I do think there are situations where weather should result in race cancellation. My argument is that 70-85 degree temperatures with a nice breeze is not one of them. Also, people die at large endurance events for all sorts of reasons, and even when it is hot, that is only ever one contributing factor. As I stated before, it is close to impossible to "run yourself to death" in the heat. Many times, correlation without causation occurs in these cases, when the reality is the individual may have died in a cold and rainy race. At the end of the day complex situations like these are all about risk tolerance, which becomes more of a legal, societal and cultural question than a medical one. I would love to hear a lawyer chime in...