Fading in the last hour of a 3 hour gravel race

In my mid 60’s and have been road and cross racing for a very long time…40+ years.
Started doing gravel events 3 years ago and I’m finding that I’m abruptly fading and begin to lose power, legs cramping in the last 1 hour of a 3hr race.
Any training suggestions to make this issue improve?
Also, I’m well fueled and hydrated at the start of the race.
I begin taking in carbs (Gels) and have consumed 1 bottle of water or Skratch fuel by hour 2 of the race.

How many grams per hour of carbs? Could be fueling related, or just fitness. If you’re going relatively hard, probably want to be shooting for 75g+ per hour.

Sodium / Electrolyte need is pretty individual and depends on the conditions.

From a fitness perspective, upping your volume and getting experience working up to race pace/time will help, as will proper pacing relative to your fitness.


Pretty much just echoing the above. Make sure you have practiced the time, distance, and terrain, are getting enough fuel, aren’t going out too hard at the start, have experience with the conditions (heat? dirt/gravel? climbs? long solo stretches?)

If you’ve done it in practice, you can do it on race day.


No “Power” numbers but for the entire 3 hrs “Heart” average was at 92% of max (183)
Spent 2:40 hrs at Threshold & :20mins above that at Maximum

Echoing others above on nutrition, how many carbs are you taking on per hour and are you fueling just before the start too?

In my experience many gravel races require far more time around ftp or SST/tempo depending on the length than in road racing, you just have much fewer drafting opportunities and need to expend more power than you might in a road race.

Something seems very strange there. I don’t think I’ve ever heard of anyone who can hold power/HR at or above threshold for three hours.


Yup…I held my HR at 159 for 2:30…not sure what’s odd about that.

Correction 2:40

Way more carbs. Try 60-70 grams per hour. What’s your longest training ride usually?

Also if you’re actually 90% of your max heart rate for that long that’s impressive.

I’m not surprised by the heart rate. I’ve maintained threshold HR for 2+ hours during marathon XC races.

Definitely more carbs. Probably more sodium and electrolytes as well. I’ve seen a lot of people who can go for 2 hours or so, pretty hard, but then completely run out of gas - they usually don’t do much in the way of nutrition…

Sorry, was thinking threshold power. But no power data in this case.

Longest training ride is 2.5hrs thus I’m thinking that I need to be doing some 3.5-4hrs


Cross bike has no power metre so
I monitor my heart to stay between 155 - 166 on the flats. Hills will push it to 168 - 174

How many grams of carbs per hour? I’d imagine going that hard you are burning thru your glycogen pretty fast.


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I would start here….one bottle of water or Skratch for 2 hours is likely leaving you under-fueled and / or dehydrated, especially if it is the regular Skratch and not the high carb version.

You should be closer to one bottle / hour.


I think I need to feed better (more often) but more importantly do more longer duration training rides that get me up to a similar timeframe as my events.


For reference, one serving Skratch is 20 or 30g of carbs depending on how much you use (standard instructions are 1.5 scoops in a big bottle, 1 scoop in a small one).

On a 3h endurance ride, sure. Some people would take more, some people do their endurance rides over 3h and really should take more, but this would be fine for me.

If it’s 3h at a very spicy pace, then going to need more carbs. For those of us who started cycling earlier on, we may have been told 30-60g/hr in our youth. I know when I started (I’m in my 40s), I definitely didn’t even get that much. It took me a while to comprehend this.


If you’re only taking in 20-30g an hour, I’d start by tripling it for a hard 3 hour race.


I was going to say the same, but want to add that it may not be easy for your stomach to handle that much Skratch. Mine couldn’t. I’d you experience gastric issues, you’ll need to either make your own mix (several threads here about that) or experiment with other carbs (gels, maple syrup, whole foods, etc).


A few thoughts here…

First, they aren’t mutually exclusive. You can (and arguably should ) do both.

Second, there was a similar thread here recently where a rider was saying that he was coming up short in the final hour of relatively fast 3 hour group rides. Many here were pointing to his nutrition as the culprit while, IMO< the issue was that he was only training 3x / week (including the group ride). It seemed raltively clear that he lacked the foundation / fitness for the ride.

OTOH, you have a wealth of experience and foundation. So you “Should” be able to handle a 3 hour gravel race fairly well (assuming you have been doing longer endurance rides across your training history). Given your above sentence re: 1 bottle / hour, it seems that your primary issue is a fueling issue, not fitness/ foundation.

Should you start to do longer / harder rides? Absolutely can’t hurt (assuming you can tolerate the increased training load). But I’m willing to wager that if you just increase your carb intake for the rides, your performance will improve dramatically.