Thoughts on Endurance MTB Race Pacing

My two A races each year are typically some endurance mountain bike races. One is esssentially 50 miles (4-4.5 hours) with some elevation change and the other is a flatter 6 hour race. My training is mainly focused around those, but I ride much more on the road than trails these days because I prefer the social aspect of road riding and the longer duration. In my many miles of z2 and road pacing, my approach going into these mountain bike races has been to do the same by maintaining a nice steady sustainable z2 average, but I’m not certain that is the fastest way to ride a mountain bike. So I’m interested in what has worked best for folks in these types of events.

Do you find trying to stay steady tempo, even on climbs, on descents, flats is faster because you stay fresher longer by avoiding any spikes above threshold?

Or do you find pushing it a bit on the climbs, easing off on the descents and a steady tempo on the flats?

Or do you push it on the descents and flats, but try not to blow up on the climbs and just go all out the whole time?

It seems easy to ride like I want up front (what feels right for a normal fast run), but then end up paying for it later when I’m spun out. But also it feels like slow and steady is slow and slow.

Pick of elevation profile of my end of march event for context.

i try to race with an IF of 0.8 - 0.85 on these longer races. It is tough not to go too hard in the beginning and no matter how hard you try to IF will probably be higher than 0.9 after the first 30 mins or so. I have tried a negative split and felt a lot better at the end but it takes dicipline to watch everyone pass you at the start and may not be the right thing to do on some courses.

Your profile looks like it is quite a flat race but I try to sweet spot long non technical climbs. If it is fast and wide try to draft as much as possible.With technical climbs and pinches you just have to go for it without trying to blow out. I like tech so go fast on the descents.

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Whenever I try this on XCM and MTB 100s I’m always slower. The last 3rd of the race will always suck, it doesn’t seem to matter if I pace it evenly or go off RPE/feel.

I’d recommend a little more on the climbs, active recovery down hill and draft on flats. If it makes drafting sense to push more on the flats to stay with a group do that. However, really pay attention on RPE for the first 3rd to ensure you don’t go out super hard. Don’t be afraid to let groups go if it’s well above your abilities.

My last XCM for reference.


yeah, I think this is why pacing xcm is so hard. you are just too slow on the climbs if you don’t go over threshold much of the time and you only have so many matches that it’s hard to avoid eventually hitting the wall.

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My strategy is mid-high tempo by default and just touching threshold on the climbs. Going over threshold can often will kill you at the latter stages.

Holy hell there’s a difference between your 4hr events and mine.

4hr 75k 1200m elevation vs 4.5hr 75k 2000m - not too different.
But looking at the power:
IF .69 vs .99
NP 221 vs 249
TSS 200 vs 434 (based on our ftp differences…)
3% anaerobic vs 27% for me (!)

Is there an Amber’ism to describe the multiple ways to skin a cat :smiley:

Like boxing: “Everybody’s got a plan until you get punched in the face”.

Course demands can make the spectrum for XCM really broad. Repeatability can be key on singletrack heavy courses where you need to stay on top of the gear to maintain momentum, especially if there are reasonable descents for recovery. In my mind, this is pure xc, that matches the TR XCO model.

Many mtb marathons are more tempo focused however, the profile for yours looks very continuous rolling terrain, with demands perhaps aligned more to the rolling road race.

. 99 IF for 4.5 hours has me wondering what’s wrong with your data, or what your FTP really is… (Avg power looks feasible, never seen an IF that high for that long)


I know right? It’s not isolated, here’s a sample size of 20, from three different power meters over the last 5 years

I was more thinking that your FTP is higher which is throwing it off. Either that or there’s so much variability in some of those rides that the NP is inflated.


You must ride like a light switch :stuck_out_tongue_winking_eye:.

Speaking of pacing. I have a suspicion, that going hard early might be faster. We’ve discussed it here on the forum in the past, and it’s obviously very dependant on not completely cooking yourself, but I’ve had some faster results starting hard and hanging on.

I also have a propensity for long and more steady efforts, I don’t seem to slow up that much more in the back half, it just hurts a lot more.

It might also be that I’m going normal pace but my inability to hit out super hard means it feels worse than it is?

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I get that, and agree it’s probably a little of both. For Russel’s question, I’ve definitely learned to ‘take the top off’ efforts during races, to avoid burning matches. I have a high short power and low threshold, so it’s handy to know what yours is and pace to your strengths.

@russell.r.sage I’d recommend taking a look at the power page on to see where your strengths / weaknesses are. Example:

I think this is possible, however i clearly slowed in the second half, and not by a little. So the question becomes, is going hard for a time so much faster on a mtb that it more than makes up for the slowdown later. In one of my races that was 8 laps, that seemed true. I was about 5 minutes faster than pace on laps 1 and 2. So much so that doing the sec9nd half of the race at slightly slower than pace did not negate those 10 mins i gained. However, im not so sute that held up on my 50 miler, possibly because of the elevation increase during the slower half. Thats almost a double whammy.

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Yeah, don’t get me wrong. I’m not recommending it per se. I usually plan for and try to ride a negative split, or at least as close to even pacing in terms of Power.

I’ve just noticed a few times that I have gained a lot of time early that doesn’t seem to come back if I start too conservatively. It can also lead to an early crash and burn.