This isn’t an article about weight loss. There’s an entire debate about the role of weight in climbing performance, but that’s not what we’ll be discussing here. What we will be discussing is the role of calories in training and sending while maintaining weight, because sometimes they get shortchanged even when your goal isn’t to lose weight; in the pursuit of lightness, we hold ourselves back.
As a group, climbers are a lean bunch. The average climber has a healthy weight, and while they may harbor a secret goal to drop five or ten pounds someday, for most it’s not an active goal. There’s a problem, though: even though most climbers are not actively pursuing weight loss, their diets passively reflect the desire to be light. Calories are skimped on not to lose weight, but to err on the side of caution in regard to weight maintenance. And the end result is weight maintenance at the sacrifice of performance.
Most of us think of weight maintenance as a thin line dividing weight loss and weight gain, like inching along a precipitous ledge. We hug the wall of weight loss—too sheer to easily scale but comforting to know is there—because it feels dangerous to walk close to the edge of weight gain. Weight maintenance isn’t a narrow pathway, though; it’s broad enough to comfortably stroll, and you can make the most progress somewhere in the middle.
Weight maintenance isn’t the balancing act we fear. By and large, our body wants neither to gain weight or lose it, and as our daily caloric intake and expenditure changes (sometimes drastically), our body shifts metabolic priorities around to manage weight balance for us. It’s only when we push outside the realm of “normal” that we can break this physiological status quo—homeostasis—and gain or lose weight. This is partially why weight loss is so challenging to achieve and maintain; it’s beyond the normal conditions of our body.
For the chronically low-calorie but weight-static climber, caloric caution causes worse performance and recovery because your body doesn't expect the calories necessary to exercise or recover from exercise. The low caloric intake reduces levels of anabolic hormones like testosterone and insulin while increasing catabolic hormones like cortisol. It’s not a major shift, but collectively the changes disfavor the creation and maintenance of lean body mass (i.e., muscle) because it’s metabolically expensive. The body decides that it's better to minimize—and in some situations, lose—that tissue until caloric conditions are more favorable.
Your performance and recovery also take a hit. Approximately 30% of our daily energy expenditure comes from non-resting activity: exercise, non-exercise movement (like fidgeting), and the thermic effect of food (the energy spent on digestion). When you reduce caloric intake, you reduce the number of calories your body is willing to spend on non-resting energy expenditure, which reduces your energy available during exercise. These “saved calories” are insidious—you won’t notice they’re missing. Instead, you’ll simply work a little less hard every time you climb or train; you’ll feel just as strong, but your throughput will be reduced.
On the other hand, as you begin to tread closer to weight gain, you body has ways to minimize the effect on fat stores. You become less metabolically efficient, which sounds bad but just means your body starts using unneeded calories in ways that don’t produce energy. If you’re active, you’ll also likely increase caloric output during exercise, either in the form of greater average intensity or longevity. When caloric intake is higher, more calories are available for recovery as well, improving the frequency at which you can climb and train. In short, your body uses the extra calories, occasionally wastes them, and—only in the case of true excess—stores them.
Really, what the body excels at isn’t just adapting to the amount of energy we’re providing, but in sheltering us from the consequences of daily variation. When you hold calories back—not in so great an amount that you lose weight, but on a moderate level—you’re unlikely to notice that you’re training a little less hard, recovering a bit more slowly, and fidgeting less at work. You’ll feel fine, and since the scale doesn’t budge, it may feel like you’re doing something right.
As an experiment, I encourage you to increase your daily caloric intake. Not by a lot, and not all at once, but in small steps: only 100 calories a week until you start to gain weight. If you want, watch the scale. Chances are you can increase your daily intake by several hundred calories without seeing weight change—or with only a small, single-time change—one of the first adaptations your body will make is increasing your caloric sink in the form of muscle glycogen, which will increase your weight by about a pound, but also improve your power endurance and longevity while climbing. More importantly, I think you’ll be surprised at how much better you feel.
I don’t expect you to start measuring your calories daily and that’s not the purpose of this article. It’s about overcoming the “less is better” mentality towards food, particularly when you’re not pursuing weight loss (if you are trying to lose weight, “less” remains an unfortunate key provision). It’s about choosing to bring extra food to the crag for a day of climbing instead of getting by on as little as possible, knowing you’ll get more out of your day.
If your goal is to climb better, it serves you to eat as much as you can, right up to the point of weight gain. The more calories you have available, the more you can do with them. For a climber, that means better performance even when the numbers on the scale don’t change.
As a certified sports nutritionist (MS, CISSN), Brian Rigby works with climbers and other athletes at Boulder’s Elite Sports Nutrition in Colorado, writes at Climbing Nutrition, and discusses the scientific aspects of climbing performance as co-host of the ClimbSci podcast.