Sneaky Ways You Under-Fuel as a Mountain Athlete
Written by: Alyssa Leib, MS, RD
It’s been a busy couple of months here at Peak to Peak Nutrition. Climbers are closing out mountaineering season with successful summits of Denali, Rainier, and Baker, and I’m up to my ears in fuel plans for summer races and big mountain adventures.
As training ramps up, one of the most common concerns I hear from athletes is: “I want to make sure I’m eating enough.”
And I get it. Eating enough to support big mountain goals isn’t always straightforward. Between long training days, early alpine starts, busy work schedules, and trying to keep your house at least kind of clean, it can be surprisingly easy to fall short on nutrition, even when you’re trying your best.
If you’ve been here a while, you know that adequate energy availability (AKA eating enough) is one of the foundations of athletic performance. Consistently under-fueling can contribute to Relative Energy Deficiency in Sport (REDs), which can impact everything from performance to bone health and injury risk to menstrual dysfunction and more.
The tricky part? Most athletes I work with who aren’t eating enough aren’t trying to under-fuel - and many don’t even realize it’s happening. Under-fueling can look like dieting, skipping meals, or cutting out entire food groups. But more often, it happens through small decisions, habits, and beliefs that add up over time.
Let’s take a look at some of the sneaky ways you may be under-fueling as a mountain athlete - and what you can do instead.
The Problem: You Don’t Want to Inconvenience the Group
I hear this from mountaineers and mountain bikers all the time: “I don’t want to slow everyone else down by stopping to eat.” While your friends may be grateful for their speedier Strava segments, they won’t be as stoked when you get hangry and start to drag.
The solution: Pack thoughtfully. Wear clothes with pockets or stash snacks in your hip belts for easy access on the move so you don’t have to stop as often. And if you do need to stop, advocate for yourself. Chances are, your friends need to eat too
The Problem: You Wait Until You’re Hungry to Eat
As an athlete, you know that you need to eat more than someone who is sedentary. But did you know that exercise itself can suppress your appetite?
High intensity exercise decreases the hunger hormone ghrelin while increasing hormones that promote fullness, like leptin, CCK, and peptide YY. Add in altitude or heat (which also reduce hunger), and it’s no surprise that eating after a long run or big mountain day can feel like a chore.
I’m a big believer in Intuitive Eating and listening to your body. Hunger is an important signal, but for athletes, it’s not always a reliable one. If you’re waiting until you feel hungry to eat, you’re likely missing opportunities to meet your nutrition needs.
The solution: Eat mechanically. Schedule your meals, snacks, and training fuel into your day instead of relying on hunger cues alone.
If eating feels really hard, think liquid. Smoothies, recovery drinks, chocolate milk, or even a sports drink after exercise can provide much-needed fuel when solids feel unappealing. Often, getting something in first is enough to stimulate your appetite, making it easier to eat a meal 30-60 minutes later.
The Problem: You Miss Meals Because of a Long Run or Crag Day
Let’s be honest: it’s hard to fit in a drive to the trailhead, an all-day outing, and a drive back home all before lunchtime. And even though you’re snacking during your adventure, getting in 3 square meals just feels… awkward. So, you eat an early dinner and call it a night (and wake up the next morning starving).
The solution: If you’re truly out from sun up to sundown, there may not be much you can do other than eat a large dinner and bedtime snack. But for those days that fall “in-between” (you finish your run mid-afternoon), try to eat a recovery meal ASAP and another one a few hours later. For example:
6am: Start the day with a balanced breakfast, such as a bagel with peanut butter and banana.
7am-3pm: Fuel your adventure to the fullest with hourly carbs and regular protein.
3pm: Re-fuel with a sandwich or smoothie from the cooler in the car to start the recovery process.
7pm: Eat a regular dinner at home.
9pm: Top off with a bedtime snack with protein and carbs (this will help with sleep too).
The Problem: You Don’t Want to Carry the Extra Weight
You paid a premium for an ultralight backpack and tent setup. Shouldn’t your food be ultralight too?
It’s true that foods like almonds, cheese, and salami are staples in the mountains because they’re calorie-dense relative to their weight. But when those foods replace carbohydrates instead of complementing them, problems arise. Your muscles (and brain) rely primarily on carbs during moderate- to high-intensity exercise. Without enough, you’ll fatigue sooner, struggle to maintain your pace, and have a harder time making smart decisions when they matter most.
The solution: Here’s a reframe: your ultralight gear isn’t there so you can carry less food - it’s there so you can carry the food your body actually needs without adding unnecessary weight elsewhere. And all of that training? It didn’t just make you faster. It made you strong enough to carry enough food to stay fueled.
Honorable Mention: You Exist in a Culture that Reward Being Lighter
Speaking of extra weight… I couldn’t talk about under-fueling without addressing the “lighter is better” culture that exists in climbing and endurance sports. Whether you consciously buy into these messages or not, they’re hard to avoid. You hear athletes joking about surviving all day on coffee and a few gels, proudly sharing how little food they ate. You scroll past posts praising dramatic body transformations or “discipline”. You read articles promoting an optimal strength-to-weight ratio. Over time, it’s hard not to absorb the message that eating and weighing less is part of being a better mountain athlete.
The solution: What if instead of trying to lose body weight, you let go of the weight of comparison, unrealistic expectations, and the belief that taking up less space somehow makes you a better athlete? You don’t get to choose the culture you train in, but you do get to decide whether or not to participate in it. Choose to fuel yourself instead of shrinking.
If you found yourself reflected in any of these, know that you’re not alone. These are common challenges for mountain athletes, and they often happen without even realizing it. The good news is that now that you’ve recognized your own patterns, you can start making intentional changes to better support your training, recovery, and health, so you can be a fueled athlete - not a depleted one.
