If you can swing 2 to 3 weeks, why not. I went 2 days before the race and it wasn't as bad as I expected. Didn't feel the altitude at all until the run and at that point the heat was worse than air density.

Edit: Maybe I should clarify that by "as bad as I expected" refers to the altitude's effect on my performance. It wasn't a comfortable run by any means but I was still able to be a couple minutes from my PR at the time.

Oh ok cool.

Yeah I'm definitely thinking about going at least 2 weeks early to make it a kind of a vacation. I'm thinking of going to Frisco first and then possibly Blackhawk. I could go to Boulder the whole time, but think if I go higher first, I might be stronger at Boulder altitude.

Frisco is 9,097ft and Blackhawk is 8,537ft.


I'm just familiar with Frisco as I've been there a couple of times. They have a dispensary there that I like with Kaviar Sativa joints, which are my favorite (don't worry, they are plant based). And a Whole Foods in Frisco (yum!). I play poker too so I could chill out at Blackhawk and train and play some small tourneys there before the race.

Then head to Boulder for the last week or so.

Not sure yet - but appreciate the feedback. I'm not looking to shatter any records here. Just to have fun, be prepared, and be poised for a good effort and to have fun.

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https://www.strava.com/...tes/zachary_mckinney

Better off arriving 2 or 3 years before, not 2 or 3 weeks.

You can't really "adjust" to the altitude in any reasonable amount of time. True adaptation involves long periods of time at altitude. You can get used to it to some degree over a few days. But you are not going to be able to gain any actual adaptation.

Two weeks is the worst possible time to arrive.

You need to arrive as late as possible

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Eric Reid AeroFit | Instagram Portfolio
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I have no clue if there are any low elevation areas reasonably near Boulder, but I believe if you were to spent a couple weeks at altitude then get back to sea level for a couple days, then go back and race, that might be ideal - I'm pretty sure that's how climbers acclimate in the Himalayas...up a bit, then back down...up a bit higher, then back down, etc.

^^^---This. We go to Loveland/FtC every year to visit my daughter's family. I have my best performances during the first couple of days...and then it begins to degrade after that for the balance of the 10 day trips. Honestly, the run is about the same as home (Dallas), bike I see a significant uptick, and swimming sucks balls.

Last year I set several bike power PRs at various durations up through 60m power, on my first ride in the foothills. Man I felt strong that day.

Agreed.

Just went to Colorado for vacation. I live much lower (like 3000 ft) and went up to 9500. XC skiing felt pretty decent at 10K for the first 2-3 days, then shit got ugly. The longer I was there, the more I felt the altitude,. I would arrive no more than 3 days before.

I've gone to Colorado for a few events over the last few years.

For the Mt Evans Hill climb I usually go about 5 days before the event. Ride every day i'm there. I usually stay with a friend near boulder and gradually work my way to higher altitude. Day after I flt in we may ride to an elevation of around 8K feet. The next day may e 9-10K,and the day after that a little higher. Coming from sea level thats not enough to fully adapt, but during the hill climb I felt fine riding up to 14K.

One guy I rode with this year flew in the day before the hill climb and said it was much harder than the previous year when he came out a week before. Next time he will be coming out earlier.

For 106 west which was a 70.3 in Dillon which is around the lake from Frisco I think I went out about 1.5 weeks before. I spent a few days in denver, a few in Boulder, and a couple in Dillon before the race. The swim was probably one of the hardest I have ever done. The cold water temp plus altitude made for what felt like a long swim. My swim time wasnt too far off my previous 70.3 swim time. the bike felt good, and the run was hard.

I find swimming at altitude tough. I've swam a few times in boulder and I could feel the altitude effects immediately. My heart rate is elevated and im breathing fairly hard even at low intensities. Biking at altitude I find not that bad.

If you can go 2 weeks before that would probably be ok. You may not have enough time to fully adapt, but IMO its probably going to be better than getting there right before the race.

Yep, I went to Colorado for a week in July, and never felt great the entire time. My running out there pretty much sucked the entire time.

I have a friend who was training for Leadville, he went out last year for like 3 months. Not sure that it really did him that much good.

I’ve blamed all of the issues I’ve had with leg cramps and such even visiting my wife’s family in Sedona to altitude as well. Feel good training for a few days then no matter how much I hydrate after a few days my legs just give out on me. Sucks big time!

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Thank you for saying that and making me feel normal. I've lived here for a few years and I still find that I can't hit the numbers that I used to hit at sea level. When I travel for extended periods I feel like it takes 1 weeks just to get back to normal.

Ironman Boulder is an awesome race, but I'm not sure if I'll ever race it. The altitude is real and the heat the past few years has been record breaking. If you want to see the struggle bus, look up the video of Sam Long who was running in third and he laid down in Boulder Creek for a solid minute or so to cool down. It's a tough race, there's a reason the run times have never been that flashy.

I also hope they adjust the bike course, that thing last year was just a gauntlet of doom. The course designers essentially picked the longest slogs throughout Boulder and had participants do it twice. Best of luck to all racers, it's a tough one.

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Team Zoot 2023

Go listen to Flo Cycling's Faster podcast and their latest episode where they have Robert Chapman break all of this down in detail.

https://soundcloud.com/...and-race-at-altitude

I have raced IM Boulder in 2015 when it was in August and the half in 2011, 2017 and 2018.

You would need a long period of time before true adaptation occurred to affect your race performance. Maybe 3 weeks would give you some adjustment, but after those 4 races and coaching several more athletes for that race, of which one was in full FF gear for the run, the biggest key is not just the altitude. Yes, it will rob you of some oxygen for use, but what will get you is dehydration. Sweat evaporates so fast and you don't notice it like you do in humid areas, that you can get in a hole FAST. No amount of coming early can really get you past that. Focus on hydration leading up to and on race day.

I've had crappy races and I've had breakthrough races in Boulder. For all of them I was out there maybe 2 to 3 days before. The only factor was how I approached hydration as all the races were in August. Not nearly as hot as Boulder 2018 in the heat btw.

Here's a vid of my FF athlete talking about her experience.

https://www.facebook.com/...os/1910853252269841/

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Ryan
http://www.SetThePaceTriathlon.com
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Research says at least 2 weeks otherwise go there like you would for any other race.

Thanks. This helped a lot.

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https://www.strava.com/...tes/zachary_mckinney

Yeah - I’m all about hydration, especially the first couple days at altitude.

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https://www.strava.com/...tes/zachary_mckinney

You seem so sure of yourself - haha

ahhh man I should have never left slowtwitch ... very entertaining

I did break the 100% plant based diet though - gotta eat those double bacon cheeseburgers :P

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https://www.strava.com/...tes/zachary_mckinney

Thanks - yeah I think the PulseOx on my watch will help to give me an idea.

I brought it to CO a few months ago and saw what looked like an adapation over the first few days.

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https://www.strava.com/...tes/zachary_mckinney

Thanks for the feedback! Yeah that is about what I was looking for. Was worried it might be too easy with such little elevation gain on the bike.

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https://www.strava.com/...tes/zachary_mckinney

Frisco is too high if your body isn't used to the altitude. Try to find something at or just below 8,000 ft.

I would suggest either 3-4 weeks early or show up just before game time. 3-4 would be best if your lifestyle can swing it. 2 weeks puts you in the danger zone for maximum suck.

Be my guest... show up two weeks early

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

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I came out last year 7 days early. I don't know if it helped with getting more acclimated to the elevation or not, but it didn't hurt. If nothing else, it gave me plenty of time to get comfortable with the bike course and also the run course while doing some OWS is the Res. I was probably most worried about the altitude and the swim, but as long as I started out easy and just focused on my breathing, it went well. I'd probably do the same thing if I were to sign back up (which I probably will) but again, I have no idea if actually helped me. Friggen triple digits on the bike course hurt more then any altitude did last year. :-)

A local here. If you are coming early (3+ weeks) and want to go higher, rent a place in Nederland. 25 mins outside boulder and 8200ft. You can easily get to boulder for food and fun, but you a little higher up with great places to train. But make sure you are here at least 3 weeks ahead of time otherwise you'll just be really tired on race day. Good luck and see ya at the start line.

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Jeff Abbott - @run1fast
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I have done IM Boulder twice, and came from sea-level (48 feet above sea-level to be exact). I arrived on Thursday of race week, and had no problems in being race ready. Drink lots of fluid, and do a very light run and bike on Friday. To be clear though, I did live in Ft. Collins for 5 years for college years ago, so I knew what to expect when going from sea-level to mile high.

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Team Zoot-Texas, and Pickle Juice

+1. FWIW, altitude concerns a lot of people, but it's not the only or primary concern, IMO, nor is it something you have that much control over. The sun and dry climate (combined with altitude) can really take a toll when you're working in it all day. Last year's race day hit mid 90s which feels like triple digits on asphalt in the blazing sun. I feel having a good plan to stay hydrated and shield yourself from the sun, which are things you can control, is a better thing to focus on.

I too did it this past year, the altitude didn't have any affect on me but HOLY SHIT WAS IT HOT AND DRY!

Whatever you are thinking hydration wise, multiple it 10x!

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Tough Times Don't Last, Tough People Do.

Apparantly, from some serious research articles on the subject :

the 4 first day (3 to 5 in fact), nothing happen
then your fitness go down until approx day 8 (worst case)
then your fitness move up slowly (adaptation):
- at 2 weeks, you come back approx to initial level : so same as arriving the day before
- at 4 weeks you are reasonably adapted
- at 8 weeks your wife request divorce : you are fully adapted !

what about the opposite scenario - going from altitude to sea level? I always feel terrible around days 3-5 after going down to sea level.

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____________________________________

Are you ready to do an Ultraman? | How I calculate Ironman race fueling | Strength Training for Athletes |

Having moved to Boulder from sea level 3.5 years ago, I can tell you that it took many months for me to fully adapt. However, it's 5300ft so being non-adapted is not too bad. Just swim easier, dial back target power on the bike 10-15% and the run is just hard and slow at IM Boulder anyway. Plan on 15-20 mins slower than you would normally run in an Ironman. The thing that got me after moving here was the extreme dehydration - so I would focus more on that. Just arrive as close to the race as possible, focus on staying well hydrated, and dial back your effort especially on the swim.

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____________________________________

Are you ready to do an Ultraman? | How I calculate Ironman race fueling | Strength Training for Athletes |

I did experienced this coming back from 4000+m and 5000+m long trekking.

Found this article : https://www.ncbi.nlm.nih.gov/...articles/PMC3641122/

At least, it show it is common and studied

There is probably lots of research article indicating how to optimize altitude period, but did not find them now (and bedtime).

Man o man, you are getting a lot of bad advice here. First of all altitude in not an equal opportunity employer. There are 3 different levels so to speak. First group of folks are shit up high, not much to help them, they need many, many months to get the smallest adaptations.

2nd group are more neutral, they will slowly adapt, and eventually get some decent benefit.

3rd group are exceptional at adaptations, they begin to pump out EPO getting off the plane, and can have some benefit at just over a week or so.

So to answer you question, well first you have to know what group you belong to, and unfortunately you dont get to change groups, you are born to these.

Other good suggestions you got were to stay hydrated,(although I didnt see where you were told to top off electrolytes too). Dont dilute yourself drinking too much water only. The other good things you can do no matter what group you are in, is do some hard swims to feel what it will be like on race day. Probably the #1 mistake most make, go too hard early on the swim, and it punishes you for most the rest of the race. At the very least it is a long time to recover from blasting off, and often you will have a panic attack too during the swim. It just cannot be explained in words, you have to feel what controlled race breathing feels like in a pack swim start.

Other benefits are just being able to not breath so hard. Even if your blood has not adapted, your lungs will gasp for air at first, but over a few days that feeling goes away, and that is not something you want on race day.

And lastly, it is ok to go up right before, lots of people have some luck with that. But keep in mind those are folks that mostly know altitude, and know how to pace differently from sea level. It is an experience thing, but if you follow advice well, then you can avoid many pitfalls that virtually everyone has had/has racing at altitude..

Good luck, I loved high races, but of course I'm a 3rd grouper!!!! 1 week and I would feel great, and that would be working out hard everyday. By day 10 I was on fire, doing as well as those that lived there. But my normal HCT% was just about 50 at sea level, so I had that going for me too.. My buddy Paul Thomas would be around 52%, he would be ready in about 4 days to race high, but that is just the luck of the genetic draw, unless you have your own longevity doctor!!! (-;

I believe there have been a few cases over the years of riders that have spent their whole life at altitude and they really struggle when they go down to sea level. When I was living in Colorado, and traveling back Ohio to see family, I really struggled with the humid, heavy air for the first couple days. My lungs have always felt best around 7-8,000 ft. Even if my power if lower, it just flows so nicely in and out of my lungs.

Interesting

Based on genetics ?

Any reference to a (public) research article studying these adaptations differences ?

Like others have said, if you can get three weeks great if not just get there like a normal few days ahead and race. Remember, thinner air and less oxygen. That means back off your bike effort just a tad and you will still be just as fast cause of the thinner air. back off the run just a hair and take lots of fluids..... I took 10 watts off my bike average and still went way faster than I thought and PR'ed on the old course in 2016. On the run I didn't hydrate enough and paid for it the first half of the run but got enough fluids in me that I ran just fine the second half of the run

Based on genetics ?

Any reference to a (public) research article studying these adaptations differences ? //

Over the years several have been posted up here by others, but my search function abilities prevent me from finding anything so specific. But as I recall, it was just about 1/3, 1/3, 1/3 for the 3 groups I mentioned. My guess is that it is based on your ability to produce EPO quickly, and in quantity. My production almost doubled in just 10 days, others might sit at a low level for a long time before reacting. Of course mitochondria size, red blood cell counts, etc, will all be factors too.


But when you think about it, makes sense that different groups would tolerate altitude differently. You have populations where the average HCT% is in the 30's, and one I found where the average male was 60%+, females in the low 50's. With such a wide variance in adaptations, of course we should expect that people will react quite differently when put under pressure up high..

I'm in the 1 week camp (unless you can be here around 6 weeks early).

Think of it this way, the altitude is a new stress you're adding to your workout load, like suddenly upping the mileage or intensity. When you change up your workload, most people feel challenged the first few days but then a little better, mainly because they get better at the workout and not really any adaptation taking place. But that stress change starts to add up and you start just having to grind through it around week 2 onward, until you can absorb it some time after 4-6 weeks. I wouldn't want to do the race at the time I'm starting to feel the struggle.

I wouldn't go higher either, it's not like the race is at 14000 feet and you need to do the mountaineer thing. You'll probably ride up that high outside Boulder anyway just to check it out. I'd come a week early and stay the week after. Golden Gates for tourneys, Ameristar for cash (we have a $100 max cash bet here if you're not familiar with spread limit).

Correct.

Basically what happens is after the first day, the body gets busy adapting - initial decreases in blood plasma volume, then increases, EPO generation, more red blood cells, etc. All of this has a high metabolic cost.
Adaptation to altitude is affected by many other factors, where 2 weeks is a best-case scenario. 4 weeks is better.
Or, arrive one or two days before, is simplest..

I used to go to university at sea level and return to 6000ft-odd for vacations, normally took about ten days to feel better.

Excellent review article by Corrine Malcom,
https://www.irunfar.com/...ude-acclimation.html

I did a hot and windy 70.3 at 6000 ft last year.
It was miserable!!!

I think:
1) Elevation means less oxygen.
2) Heat means more blood needs to be sent to the skin - thus also less oxygen.
3) Elevation + dry heat- means super rapid dehydration.
4) Dehydration means thick blood, means heart has too work harder, means less oxygen.

There were a few people that appear to have avoided a complete meltdown at IM Boulder last year.
But not many!

Anyone here execute reasonably well last year?
Want to share how you did it?

(I realize 80s are more likely than 90s).

I was going to say this. It took me a good 2-3 months to "adapt" to altitude where I as comfortable on my easier days and probably 6 months before I was feeling good on harder workouts. 2.5 years later and I don't notice it much anymore. But when I moved here, there was no way I could do sustained tempo runs or anything without dying.

That was a good article, not sure why he waited to the very end to say what I have been saying all along;
Individual Variability
"Like with anything, there is a degree of individual variability when it comes to altitude acclimation. Physiology operates in shades of grey for multiple reasons, including genetics, so don’t get too hung up on a generic timeline for acclimation or the potential outcomes. There is room for experimentation".
He hits on all the points, and I love the new line about cross acclimatization. I will have to try that sometime to see if I notice anything, as I go back and forth to altitude all the time. And need more evidence that there are groups, just look at the responses here on individual stories, going from it takes 6 months to 10 days.. On that alone I could tell you what groups people fall in...