Pacing for a century using FTP %

It seems its usually talked about in most podcasts and I can’t seem to find much info on it online. How do you calculate a % of FTP to stay at for a long race? I think it might be a triathlete/time trail thing? I’m looking for suggestions on how pace myself on a 128 mile upcoming race. While i’ll be riding in the race category, due to some unforeseen issues I’m just planning on riding and surviving. The race was supposed to be a relay team in the LOTOJA race here in Utah/ Wyoming. 202 something miles and 8,900 vertical feet. The original plan was to leapfrog with a relay partner over 5 legs with one rider doing 3 legs and the other doing 2 legs. While we hadn’t spoke about it, I was planning doing the 2 and ending up with about 80 miles and maybe 1,000 vertical.

Well, my partner dropped out. I called everyone I knew and I couldn’t find a new teammate. The race organizer found someone else in my position and due to their fitness and scheduling, and my desire to still ride as much as I can, I’ve chosen to ride the first 128 miles. It ends up covering about 7,000 ft of climbing over that 128 miles. Year to date, the longest ride I’ve done was probably either a 2.4 hour MTB ride or a 3 hour 50 mile gravel ride. The race is in two weeks and while I’m on a uptick in training and ftp, I’m still a bit nervous about finishing my segments. I know I can stay tucked in groups most of the way but I won’t be able to hide on the climbs. I’ll in theory have fresh teammates on other relay teams for legs 1 and 2. As a side note: I have completed the entire race by myself about 10 years ago, and 4 years ago did the relay with a partner, but had the breaks in between. going all 128 at once is what I’m nervous about. I’ll end up with a 14 mile 1600 ft climb finishing at mile 106.

On to my real question: how can I or should I calculate a % of my ftp to try and survive the day? I’m confidant that I can go deep but I’d love some sort of plan… anyone have any resources?

Low z2, especially if you haven’t been doing the 5 hour efforts already. If you have data out the the duration you’re going to have to do just take that number and knock ~5% off for wiggle room.

It’s more of a TT and tri thing because those races tend to be on courses where you can lay out steady power throughout. For road racing where you have time to recover on descents and in packs it’s not so easily applicable. For your event I would say the best approach is to have a power cap that you don’t want to go over, particularly on those long climbs. E.g. Something like 90% of FTP for long climbs, which is hard but not putting you into the red and should be both sustainable for long efforts and repeatable. If you’ve got a good base and it looks like you’re going to be in a decent pack on the flats to recover then maybe you could go a bit higher than that. Conversely if endurance is a concern and/or it looks like you’re going to be working solo on the flats so need more of an all day power vs a climbing power then you might need to go lower.

Also need to weigh up on the day the balance of sticking to a power target vs surging to stay in a pack. Usually worth digging a little deeper on the flats and short hills if it means you can get a draft rather than riding solo. Though on events with a lot of riders and a lot of climbing I find the groups get split enough that there’s nearly always one not far behind so best tactic can be to soft pedal until one comes along rather than busting a gut riding solo.

I’ve used the formula of %FTP=0.95-(0.05xhours). So if I’m going to ride for five hours, I target 70% of FTP [.95-(0.05x5hrs)].

To know how many hours I was going to be riding I used Best Bike Split. I just used this for a 207 mile event and it worked very well. There’s probably a smarter way to do this, but I entered in a best guess IF into best bike split, put that finish time into the equation, and made sure it matched my IF input into BBS.


If you know your zones I’d ride tempo for most of it.
The climbs will push you higher but the downhills and bunches will let you ride easier.

If you have best bike split you can calculate the course and hold that NP number to get you to the finish. That is what I have done for some tris and works susprisingly well.

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What does your power duration curve tell you about efforts over that period of time?


Tempo for 5+ hours with the OP’s recent riding background would suck.


From Joel Friel’s Power Meter Handbook. In your situation, I’d shoot for low Z2 like Erick wrote.


Is this average power or nomalized?

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IF so normalized

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Just thought I’d share some stats from my 150mile gravel ride recently, my pacing wasn’t super great and sort of lost motivation toward the latter 50 miles (and I was taking it easy chatting with someone I ran across), but kind of gives an example:

150 miles: 0.65 IF
100 miles: 0.70 IF
75 miles: 0.73 IF
50 miles: 0.77 IF

Wanted to be within 0.7-0.75 for the whole thing and in the future I’ll have to try and get to do that. Only having ridden 100miles ever in my life, the last 50 miles especially were tough on my body, not from a power/endurance perspective but some of the physical and mental stuff from being in the saddle for so long. Anyhow, just thought I’d share my recent experience

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65-70%. If you had more training in the legs it would be better to go a bit harder over the hills and recover on the downhill, but since you have little FTP --> Vo2max work, that might fry you.

Ride within yourself and have fun!


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When we stop on aid stations, should we stop the cycling computer or not? The IF is so much lower we I let the Garmin running while I’m stopping to fill bottles… For the purpose of using the above table and those guidelines, what would you recommend?

I wouldn’t, unless you have it set on autostop/start. If you stop it manually, you will have just one more thing to think about at the station, … to turn it back on.


I don’t recall the book stating whether to do this or not. I can look tonight but my guess is since what I shared is for Ironman events that it’s not discussed anyways.

I stop my computer at aid stations (and lunch) if/when I stop riding. I do this because I’m only interested in what I did while on the bike otherwise I’ll get unwanted data included to review at the end of the day to compare to my pre-ride goals.

Good point. Are there any potential issues with using autostop/start? Never used it before so wondering if there is something in particular I should consider…?

Makes sense. Letting it run while you’re not moving can really skew the data. The autostop/start functionality mentioned by @dlridings sounds like a good option. Have you ever tried it?

I’m in the opposite situation, that is, I don’t want it. But I have used it on occasion when out on group rides. One issue might be how it determines if you are stopped or not. If I recall correctly, some models define “stopped” as being a speed under zyz km/h or mph. You want to really set that low, particularly if there are some huff-and-puff hills involved where your speed is low anyway, even though you’re working hard.

It is discouraging to be struggling up a steep incline and your computer says “you’re not moving” and goes into auto-stop :wink:

Yes exactly. That’s why I manually pause my wahoo bolt. on my 530 I set autopause to <2km/h. I wish you could set autopause with different variables e.g. cadence 0, power 0, speed <2km/h. That would be more accurate than the calculated speed through gps