Race Advice Training - Lose Power after 1.5 hrs

Just wanted to get some takes on this: I started racing last May in preparation for Leadville. It seems like My power fades pretty significantly after 1.5/2 hours. Yesterday for example, I had my best 90 Min power of 237 on FTP of 288 at Old Man Winter in Colorado. On the way back towards end of race, on the flats I hit NP of 197 (IF .67) for one hr. Just didn’t have it. Something similar has happened at most of my races.

Is this common for you all? Any specific training tips to increase 3-4 hour power? Those are most of my distances this year.


Sounds like you are running out of fuel. How are you fueling those rides.


Sounds like a fueling issue to me too. If you’re not near 90g carbs per hour from the gun, that’s the first place to look.

Even if you are doing ≥90g/hr, I’d consider increasing further, but there still may be something else going on.


Im wondering that too… 600 calories of tailwinds in two bottles (liquid mix) for first part. Had a little left
For ride back plus 200 calories of some gel last 2 hours. Was hard to fuel early in race (first hour) when I was trying to hang onto the group.

That’s about 150g of carbs for how long? 2-3 hours? The key might be that you didn’t fuel early enough if you said you were having trouble the first hour. That may be enough time to get behind the eightball if you haven’t pre-loaded with some carbs. If it’s closer to 3 hours, then I’d say it’s not enough carbs at 50g p/h.

+1 for carb intake of 90+ grams an hour. Also, if you set a PR for the first 90 minutes, what do you expect for the remaining? You’ve done more than you’ve ever done before, so that will affect the remainder of your race. In addition to nutrition, pacing may be an issue. If you go out too hard to stay with a group then you could be over cooked and have to craw to the finish line. You want to hit a 3-4 hour PR not a 1.5 hour PR.

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Need to find a way to force the carbs in, during the first hour of racing. For 2.5-5 hr races, It’s as important as the racing itself.

Ways to accomplish this:

  1. Doing all liquid fuel, and playing with higher concentrations. (test in training first)
  2. Downing 30-70g carbs with plenty of fluid, on the starting line. My wife does this.

Basically you need to flirt with GI upset early in races to out-fuel and outperform your competitors.

I wasn’t sure if that’s what @Mick_Ribault meant, but if so, you’re spot-on.

Even if 237W AP = 90min PR, if 288 W = 1-hr PR, fueling better may still solve this completely, because 237 W for 90 minutes should be is “easy” if 288 W = 1-hr power.

People quickly go to the sugar for rescue….However, seems like you also might not have a fully developed endurance base.


82% for 90 minutes should be totally doable if you are fueling well. But if that avg power comes from a ton of spikes to stay with a group then that would be much different than a steady power effort.

Also, what does your training look like? How many rides longer than 2 hours are you doing? It definitely isn’t required to do longer rides to complete longer races but they will certainly benefit your aerobic capabilities.

Also, be sure that 288 is ‘actually’ your FTP. If you have a much inflated FTP (maybe you did a ramp test and have strong anaerobic capabilities) then 237 may be closer to 90%/

I think this as well.

How often are you doing 3-4hr (or longer) z2 endurance rides?

Start with long endurance rides, 3-4hrs mid-zone 2… then spend 15-20 min of each hour near LT1 (say 72-75% FTP or by HR or RPE if you’ve got that dialed.)

Add tempo “intervals”. Say 3 hrs with 3x20 min at 80% late in every hour.

Then add some sweet spot at the end, doesn’t have to be crazy. Ride 2:15 zone 2, then 45 min at 90% late. Build fatigue resistance. Fueling probably isn’t really the issue when we’re talking about 90min, IMO. Take in some carbs, sure, but you don’t need to be doing 90g/hr for a 90 minute ride, again IMO.

Agreed. Here is my take… TR’s focus on sweet spot and intensity made me a better sugar burner. That’s the ‘energy system’ being targeted. Changing my training to TR’s traditional base helped, but what ultimately was best for me was to use other plans with 8-12 hour/week plans that focused on 60-80% of work on endurance. Better even when life interfered and ended up only averaging 7.5 hours/week. Better even when doing two separate overload blocks ramping 9-11 hours and then dropping back to 5 hours/week.

Yep. I’ll toss in a simple benchmark for a 90 minute event - being able to routinely, week after week, go out and do 3 hours at 70% IF with low variability (indoors if necessary) and low aerobic decoupling.

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I would go here first before adding any fatigue resistance intervals. Agree. Start at .65 or so, progress IF to .7 with little decoupling Pw:HR, then add some tempo or late-ride SST.

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Lots of good suggestions, thank you! Training: FTP was from 20 min power test, and slowly been increasing since last year. Last year leading into Leadville I was doing lots more Z1/2 longer ride ( 3 to 5 hrs). Coming into this year, just havent gone over 2hrs that often. My goal was to hit some fast group rides but have only done 2 so far, due to injury. Those would replicate race pace and efforts into 3 hr rides. So… mainly sweet spot and some threshold workouts. Probably a gap there on building base, that I need to work on. Thank you for suggestions.

I think fueling has something to do with it. I always fail to fuel enough early on. I like the suggestions to fuel just before the gun, and more along the way.

Most likely a combo of things, but really looking forward to better power late… I’m going to work on this.



He said he starts to crash at 90 minutes, not that it’s a 90 minute ride. He’s looking to do a 3-4 hour ride.

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One caution: group rides are often not great for aerobic base training. Riders tend to spend a lot of time coasting or in zone 1, when what you need is steady pressure on the pedals in zone 2 to build the aerobic engine. Personally, I prefer my long rides to be solo or with one other person who understands the goal (can chat, whatever, but steady endurance riding), or sometimes I even do them on the trainer. (Zwift, movie, basketball/football game on TV, podcasts, a book…)

I see a lot of my club mates who struggle with their aerobic base doing all of their long days as group rides, and you check their power profile and it’s like a backwards Nike swoosh… half the time is in zone 1, less in zones 2-5, and then a spike in their zone 6/7. Well, no wonder!

Good luck!

Probably a little of both. At that power level, you shouldn’t be crashing at 90 minutes due to fueling (assuming no other circumstances are involved), but I suspect based on his answer above it’s an aerobic base/fatigue resistance issue first and foremost, with a secondary fueling issue.

Nice ride, I was out there suffering with you. Two things, I agree with the fueling advice here. But, it also looks like you went too hard too early. Stalking your Strava, you spent 80 minutes early in the race at a NP of 271. You’re not going to last long at an IF of 0.95 unless you have a very strong endurance base. (I get it, you were probably trying to hang onto Gould like the rest of us). You also have to factor in that walk-a-bike effort on the higher slopes of the hill, that will absolutely thrash the legs.


I think this is your issue…you haven’t been doing longer rides, and with the initial pace you set, you just blew up. Fueling was also possibly a contributing factor.