Hi all,
I’m probably overthinking this (please stop me if it’s nonsense!).
I’m trying to evaluate fatigue during a long ride, with a constant regular (no competitive) pace. I’m using the Marmotte 2026 route, that i will do this June, as a test.
I have already calculated that , with FTP = 230, total time = 11 hours, my body+bike weight, my supposed fatigue starting at 2000 KJ (conservative, 61 years old), a constant watt pace < 0.7 IF (when possible…), i will have roughly a final TTS = 615, KJ = 6280, plus other secondary indicators. Following this calculation, i will arrive at the start of Alpe d’Huez (the last climb) after 09:30 of moving time, and a fatigue measurable with an effective ftp reduced to 198 watt. At the summit, effective ftp would be around 186 watt.
The fatigue is calculated using progressive KJ produced (after the first 2000 KJ) multiplied by 0.5% every 100kJ .
So, if you have read until here, the question is: if the fatigue depends only on KJ consumed, there is no way to “train the fatigue”. Ipotetically, maintaining the same other parameters, the only way to arrive to the start of Alpe d’Huez with more dynamic ftp is to ride slower, to spend less KJ until then.
What i am missing ? I’m doubting that there is some big concept that i’m not considering.
I don’t mean to sound rude but I think you should have stopped at the beginning
The thing I think you are missing is to just go and enjoy riding your bike. You can nerd out on all the data and different scenarios you like but in my opinion it’s irrelevant.
You’ll do what you do on the day … then you can nerd out with the actual data and see if any of your modeling was even remotely accurate
(Edited to say this was intended as a positive reply)
I’m struggling to follow your post, but fatigue resistance is certainly trainable and fatigue is not linear based on Kj’s of work performed. You can be completely implode after a very hard 1000Kj effort and while you could be totally fine after riding 5000Kj at a very easy pace.
There is no magic answer/formula for figuring out the exact intensity factor is to get you to the finish line the fastest, it’s a very individual thing and will be highly depend on your fitness and ability to fuel continuously. But there are ranges that most people fall in and you can test how those feel during your long training rides leading up to the event. Once you get past ~6 hours, your power/fatigue curve is going to be really flat, so whatever you can do for 6 hours is probably not much higher than what you can do for 10+ (again, assuming proper fueling/hydration/cooling/etc.).
.7IF isn’t an unrealistic target if you have solid fitness and have experience in long events, but I’d definitely test it in training to see what it feels like in some long training rides. If you are totally dying at .7IF after 6 hours on a training ride, that’s not a good IF target for a 10+ hour event. When I do that long training rides, I’ll ride and fuel them as much like the race as I can. When I get to the end, I’ll ask myself whether I could keep riding x more hours at that pace (the approx race duration). If the answer is “maybe”, then that’s a good target for me. I know I can find a little extra on race day.
I’m confused what your goal is: to get to the bottom of Alpe d’Huez the freshest? Complete the entire ride in the lowest time possible?
If it’s the former, ride everything up to Alpe d’Huez as easy as you can. If it’s the later, that’s a more complicated question that something like Beat Bike Split can help you model
My main goal: arrive at the finish alive and cycling. It’s not so sure for me, with 10-11 hours of cycling AND 5000 mt/d+ AND 6-7000 KJ to consume. I don’t have problems with (let’s say…) 7 hours of cycling and 2-3000 mt/d+, but i think that is a different beast.
To fulfill the main goal, i suppose that the key is to arrive fresher and “refuelled” as much as possible to the start of the last climb, Alpe d’Huez. Without this last climb, i would have said “ok, it’s not easy, but it’s feasible, i will arrive to the finish”. And from this… derive what i wrote in the first post.
The idea is to predict the ideal pace for the first 2 climbs (Glandon and Telegraph/Galibier). I have already made some tests analyzing other rides done (Maratona dles Dolomites, Tour of Flanders, Gavia + Mortirolo, Stelvio + Cancano), and i’m refining all the theory.
For a day that long with climbs that I assume will be well over an hour (at least for Alp dhuze), I personally wouldn’t pace the climbs much harder than the overall effort. Either just steady all day or maybe 10% harder on the later climbs if still feeling good. Assuming you can dial in your “all day” IF, there is no reason you can’t stick to it all day (assuming you have the right gearing). Going a bit under early isn’t going to leave you significantly fresher and going over it on the climbs is going to increase fatigue in a hurry. That’s just my experience as someone who likes to ride steady state on long rides, but I’m sure it’s an individual thing. And all that said, this assumes it’s a solo TT effort. If there were other riders with the opportunity to draft on the flatter sections, I’d be sucking wheels and resting between the climbs.
You’re overthinking it. You’re going to want to spend all your time below and mostly well below threshold. Think climbing at tempo, 70-80% of threshold, and an overall IF closer to 0.6 than 0.7, rather than an overall IF of 0.7 and climbing at some higher % of any FTP. You need to cap power at tempo to survive it and have legs for that final climb, and even then I’d be more ~LT1 than Coggan tempo (so more like low 70son climbs).
Given those facts, I wouldn’t be trying to calculate effective FTP at the end of the ride. Pace it slower than you think you should at the start, and then do what you have left in the last hour.
The best way to train stuff like this is to do a lot of late effort riding, so longer rides of 5-6 hours with efforts in the final hour. Since your ride is so long, you can do “long weekends” where you simulate your event by riding and incurring fatigue on Saturday, then doing it again on Sunday but with a 1 hour climb at the end of it when fatigue is highest. This is a key way you can rehearse it without having to go do the actual ride itself.
But all these calculations aren’t going to be helpful. You’re gonna have to train, practice nutrition on epic rides, do late efforts, and then be conservative on race day.
i didn’t say before because i consider it obvious, but let me assure you all: i’ll eat and drink like there’s no tomorrow. How much ? until now, 90 gr/h are too much for my body. And i don’t think that something will change, i have already tried so many times, also on 2:30 / 3:00 hours indoor training.
I did La Marmotte 8x, it has no secrets for me. But you should aim to take at least 60gr/hour. 90 will be better.
What is your weight? FTP of 230?
Crucial is Glandon climb. Many over pace this climb because still fresh and adrenaline. The Marmotte begins halfway Galibier. Every thing before should not feel that made you super tired.And use appropriate gearing for the steeper parts.
actual 76 Kg, 230 FTP, 61 years in this world . I am used to ride climbs with relative high cadence, 34 x 34 from 8-9% up to stay below FTP. When the gradient is very steep, cadence low and speed of 5-6 km/h, just to stay in balance on bike, and obviuosly watts much upper than FTP.
With 60 gr/hour i think i shouldn’t have problems, for 90 gr/hour i’m trying again, today i will do 2.5 hours indoor in sweetspot at 70 gr/hour.
I’ve read everywhere that Glandon must be taken EASY. I also hope that the two long descents can be used to recover a little.
At the start of the Alpe, i already know i will think that also if i walk for the steepest first 2-3 km’s, i can lose not so much time and i can arrive to the finish.
… then you can nerd out with the actual data and see if any of your modeling was even remotely accurate 
