The problem that I see with Blu running a world level marathon is his weight. Speed is not linear as you know. Running 15 minutes quicker is running about 35 seconds per mile faster. And that’s is a huge difference and something that will take a lot of energy. The heavier you are the harder it is to do.
Can he do it? Yes I think he can. He would need to train differently and would probably need to lose weight to get there.
I saw that he ran a 5k road race in under 14 minutes. It’s hard to extrapolate out too far from that, but Jack Daniels estimates a 2:13 marathon off of that 5k time. Would be worth seeing how close to 2:10 he could go if he just focused on running.
So, I have done 3 x 17:42 5k races.
Jack Daniels suggest a 2:49 marathon.
I ran a 2:59:48 just 3 weeks after the first time I did 17:42.
Granted… I am just a normal guy who is not very good at this running thing. But speed is not linear.
But I would buy into him going sub 2:20 off a IM training plan and 2:10 off a running plan.
The problem with this example is time and mileage. If you can run 17:42 for 5k then 2:50 ish should be very doable…but only if you run decent mileage. 50-60miles/week with a weekly 22miler and a midweek 15miler at MP. Before I took up cycling, I ran 2:50 after running a 16:48 5k a few months earlier. 5 years later I ran 2:47 having just run 17:22 for 5k…the difference in the first case my mileage was 40miles/week in the second 60. So yes he would need a dedicated running plan of 100+ miles/week. However, at his size that may injure him.
In my case I think is more about ability and weight.
At that time I was just running. I was doing over 60 miler week with some weeks in the upper 70 (November 2016 I did 76 per week). Plus multiple 20+ run and a tempo/threshold run per week.
I am a heavier runner for my frame. I weight around 150 and just 5’6. That’s a lot of weight to carry when you are not a tall person.
At the end of the day, he is a ridiculously good athlete. He is God tier of triathletes. There is really no way to predict what he could or couldn’t do. We can only use our experience. I see him as a heavier athlete and that the only reason I say 2.20.
But, he might one day day say fuck it , I’ll run Boston marathon and he drop a 2.15 off a triathlon training. God are allowed to do that.
Mileage is definitely key… and not speaking to this specific case… but it is important to note that not all 5k runners make good marathoners. Some come from a middle distance realm (800/1500) and some come from the 10k side. There are plenty of examples of those who have been supper successful making the jump but plenty more who never could.
That said, if you are doing an ironman I am guessing you’ll do just fine at the longer stuff.
True - Kipchoge was World 5k champ in 2003…God that’s ages ago! - and an Olympic medalist but didn’t have the track pedigree of Gebrselassie, Bekele or Farah. However, none of them have ever got remotely close to beating him over 26.2 miles.
I dont know why we do these thought experiments when the answer is already in front of us 
Ironman was invented to answer the question, who is the fittest on the planet? Swimmers, bikers, runners all racing together. The answer, this year, is Gustav Iden 
Comedian on the radio just now.
If you did an Ironman against a shark. The shark is going to beat you in the swim and you’re going to beat it in the run…
…so it all comes down to the bike.
That should have been a 
joke… Since they can run and swim faster than a human.
Doing a local 5 mile cross country race on Sunday with my club. I’m still recovering from IM Cascais but I think I’ll be okay. I’m back of the field anyway. And trail shoes.
Thinking about pacing/effort…do I go for 10k race effort, or just make it a high end z2 run?
Did 1hr marathon sort of pace with 3 or 4 long walk breaks this evening and felt some stiffness in my left calf coming on.
I currently have a calf strain which has derailed my last 3 running races - but not my TT season…although I did have a couple of crashes to interrupt that 
I would give the race a miss - calf strains are hard to shift once you start getting them regularly. That said it is a bit of an age thing…I could shake them off quickly in my 20s and 30s now I’m 54 they re a pain
At 43 I am starting to feel small pains take way longer than I would like to get better… I really hope I can stay somewhat competitive in my 50s
The beauty of a five mile race is that you can send it and always back off if you don’t have it… I’d try to go out at 10k pace and see if you can hold it. If you flame out after 3 or 4 miles and just have to hold on, dropping your pace for the last mile or so won’t ruin your day, but you might surprise yourself with a great effort.
Wondering if anyone has any recs/starting points for a fairly basic everyday shoe that isn’t super heavy on the cushion/stability features but still fairly sensible?
I typically gravitate towards more “stripped-down” models like the Adios and Gel-DS (I hesitate to say minimalist because that’s kind of a loaded term, but something that would traditionally be denoted a ‘tempo’ shoe I believe) but I’m looking to build the mileage while I focus on running for a bit and starting to feel like I might need to sub in something a bit more forgiving for easy/long runs. I don’t deal well with the hoka-esque super cushy stuff though.
If relevant: fairly pronounced forefoot strike, on the lighter side, no injury history.
I always trust Asics - not much hype but have done the job for years… 1000 series if you have mild stability issues (2000 series is better but only really needed if you start running serious miles) If you are neutral the Gel Cumulus is lovely. There are lots of new brands, but their lack of history means that although they make some good shoes, there isn’t the consistency across the range. I do most of any run training in a set of 1000s (when my calf is ok) and race and only race in some Saucony Endorphin pro carbon plate racers.
If you haven’t try the not that expensive plated offering from different manufacturers, that might be a starting point.
I feel you when it come to how you like the shoes. I was on your same boat until recently. But then, thanks to a deep discount on Saucony endorphin pro, I’ve been spoiled forever. I have a pair of adios 4, that have probably less than 50 miles on them. The Boston that I bought at the same time have more miles, but still have a ton left on them. I just stopped wearing them thanks the the endorphin line…
I recently got the endorphin speed, and it’s a fantastic shoe for long run and easy runs and really anything.
If you had to make the biggest impact (from a pretty low base) on your 5k time in 7 weeks what would you do?
Strides, 400, 800 and mile repeats!
Depends on your recent run history really, but yes intervals would likely feature