Rucking and ultra-running seem like natural cousins. Both are about covering long distances on your feet, both demand serious endurance, and both reward the kind of person who’s happy to suffer for hours. So it’s a fair question: can rucking actually make you a better ultra-runner?
To answer it honestly, we went to someone who races these distances for real. Our source recently finished the Dolomiti Extreme Trail (DXT) 72K, a brutal UTMB-qualifying mountain ultra with thousands of metres of climbing. He’s a runner, not a rucker, and that’s exactly why his take is worth hearing: he has no reason to oversell rucking, and what he told us is more useful than any “rucking fixes everything” article. The short version? Rucking helps ultra-runners in some specific ways, and actively works against them in others.
First, what actually builds an ultra-runner
Before we talk about where rucking fits, it helps to understand what ultra-running is really built on.
According to our racer, the single most important foundation for finishing an ultra is a strong aerobic base. “It lets you keep going at a steady pace because you’re burning fat and delaying the point where your energy crashes,” he explained. That base is built through long, medium-paced efforts, teaching the body to sustain effort for hours without blowing up.
On top of that sit the technical skills: climbing, descending, and threshold work. But for anyone whose goal is simply to finish an ultra rather than win it, he’s clear that the aerobic engine and raw endurance are what matter most.
This is the lens to judge rucking through: does carrying weight on your back help build that engine, or not?
Summary: Ultra-running is built first and foremost on a strong aerobic base and deep endurance, developed through long, steady efforts. That’s the yardstick for whether any cross-training, rucking included, is actually useful.
Where rucking genuinely helps: the climbs
Here’s where rucking earns its place in an ultra-runner’s training, and it surprised us how specific the answer was.
People assume trail racing means running the whole way. It doesn’t. On races like the DXT 72K, some climbs are so steep that running is impossible, and even elite racers switch to fast hiking. As our source put it, the goal on those sections is “to finish the climb as fast as possible without wasting too much energy.“
And that’s exactly where rucking comes in. Walking uphill under load is, essentially, what a steep race climb demands, only harder. “I think rucking can be very useful as training for steeper climbs,” he told us, “because it gets the body used to handling more fatigue and more weight than it’ll actually face on race day.” Train your legs and lungs to power up a hill carrying 20 or 30 lbs, and doing it with just your bodyweight on race day feels easier.
For the hiking portions of a mountain ultra, rucking is genuinely sport-specific training. That’s a real endorsement, from someone with no stake in selling it.
Summary: On steep climbs, trail racers hike rather than run, and rucking trains exactly that movement under heavier load. It builds climbing strength and fatigue resistance that carry directly over to race-day ascents.
Where rucking doesn’t help: the descents
An honest article has to cover the other side, and here our racer was just as direct.
If climbing rewards steady power under load, descending is the opposite. “The main goal going downhill is to be as fast as possible while staying light and agile,” he explained. Descending well is about quick feet, balance, and letting gravity work for you, not grinding out weighted steps.
For that, rucking isn’t just unhelpful, it can be counterproductive. Its whole foundation is walking under weight, which is the wrong pattern for fast, light descending. Spend all your training carrying loads and you’re not developing the nimble, reactive movement that technical downhills demand.
The takeaway: rucking is a tool for one specific part of ultra-running, not a complete training method. Lean on it too heavily and you’ll neglect the speed and agility that races are often won and lost on.
Summary: Descending rewards speed, lightness, and agility, the opposite of what rucking trains. For downhill performance, weighted walking can actually work against you, so it should never replace running-specific work.
The mental side: the real lesson
The most valuable thing our racer shared had nothing to do with legs or lungs. It was about the mind, and it’s where rucking and ultra-running truly overlap.
He described his lowest moment in the DXT 72K: the second-to-last climb, after already covering 52 km, when his body and mind were both screaming at him to stop and lie down for ten minutes. What got him through wasn’t physical. “I thought about all the training I’d done to get to that race, even the sessions I did unwillingly. I realised the race is just the finish line of everything you did before it.“
That reframing, seeing the suffering as the reward rather than the enemy, is what kept him moving. And it points to something rucking and ultra-running share completely: both are as much mental training as physical. In his words, “if you’ve prepared properly, your body can handle the fatigue, it’s the mind that makes you throw in the towel.” Learning to keep going when everything says stop is a skill, and long, uncomfortable efforts under load, like rucking, are one way to build it.
Summary: In endurance events, the body often outlasts the mind. Our racer’s breakthrough came from reframing fatigue as the reward for his training, and mental toughness like that is something both rucking and ultra-running develop.
The one thing people underestimate about carrying weight
We asked what most people get wrong about carrying a heavy load, and his answer was pure rucking wisdom, from a runner who arrived at it independently.
“It’s not enough to just put the backpack on,” he said. “Otherwise everything falls on your shoulders and after a few hours it really hurts. Tying the pack down well, so the weight is carried by all your muscles, is essential to feeling less fatigued.”
Any experienced rucker will recognise that instantly: load placement and a snug fit are everything. The fact that an ultra-runner landed on the same principle, purely through hard experience, tells you how fundamental it is. If you take one practical thing from this article, let it be that: how you carry the weight matters as much as how much you carry.
Summary: Simply wearing a pack dumps the load onto your shoulders. Strapping it snug so the weight spreads across your body is what makes it sustainable, a core rucking principle our racer discovered the hard way.
The honest verdict
So, can rucking help ultra-running? Based on someone who actually races these distances: yes, for some things, and no for others.
Use rucking to build climbing strength, load tolerance, and the mental toughness that long efforts under weight develop. Don’t use it as a substitute for running, especially the fast, light work that descending and speed demand. Treat it as one specific tool in a bigger toolbox, and it has a real place in an endurance athlete’s training.
If you’re an ultra-runner curious about adding rucking to your climbs, start light and treat it as a supplement, not a replacement. And if you’re a rucker inspired to test your endurance further, our rucking vs running comparison is a good next read.