By Laura Ingalls, Certified Holistic Health Coach, NASM Personal Trainer, Certified Running Coach

In 2014, I trained for the Boston Marathon and got fat.

I know, right? WTF?! Marathons are supposed to make you powerful, sleek, and svelte — like a gazelle. I was eating clean, healthy foods. I was exercising. I’m a health coach — a nutrition expert for goodness sake! I was doing everything “right” (or so I thought) and yet my body packed on 16 pounds of… well… not muscle.

Many of my running girlfriends have similar stories to mine. In fact, the weight gain I experienced last year was not the first time something like this had happened to me. It happened several times before while training for races.

In this insane “health” paradigm we live in, it is still widely accepted that if you gain weight, it’s because you are eating too much and not exercising enough. But this isn’t the only assumption made about food and exercise that people buy — hook, line and sinker. Nearly as often as I hear the calories in, calories out theory, I also hear the, “I’m training for a marathon so I can eat whatever I want,” theory. Cupcakes are on the menu because of “running.” Well, I’m here to debunk both of these theories. Our bodies are so much more complicated than that.

Before you go blaming yourself for getting fat and hating your body for being un-gazelle-like, here are three possible reasons you might be gaining weight while training for a marathon and what you can do about it (and, for the record, my weight gain was due to reason number 3):

Reason 1: You are replacing calories but not nutrients.

As a result of burning so many calories during training, you eat just to replace calories. “I’m running, who cares if it’s a cupcake? Cupcakes are only, what, 500 calories max?! I just burned 2,500 calories before 10 a.m. This cupcake isn’t even going to register on the calorie meter.”

Unfortunately, food is about more than calories. Food is about nutrients.

Nutrients make your body go, not calories, and runners use up a lot of nutrients while training. If you’re eating just to replace calories and not taking care to get protein, vitamins and minerals, you may find yourself in a bad place rather quickly. You can become iron deficient, you can experience muscle breakdown, your B12 and D3 levels can drop. Your electrolyte balance can become slightly off. Your body stops being efficient. It slows down. It packs on weight.

What you can do about it: Eat nutrient dense foods.

Don’t double up on foods that have no nutritional impact like the empty carbohydrates in cupcakes or pasta. If you’re going to go overboard on anything, make it fruits and vegetables. Hit those sweet potatoes hard! Toss back handfuls of spirulina like it’s going out of style. Snack on clementines, sweet peppers, and carrot sticks like they’re popcorn. Smother avocado on everything. Grass-fed beef? I’ll take seconds, please! Free-range chicken? Bring it on. Oh, and definitely add that extra smoked salmon to your classic egg and whole grain toast stack. Buy a bag of mineral salt (my favorite is Redmond Real Salt), and get liberal with it. Romaine and spinach salad with salt, olive oil, and lemon? Yes, yes, yes!!

Foods like these will not only satisfy your hunger, they will also help your body recover and perform better. They will replenish your vitamins and minerals, unlike empty carbohydrates that tax your body’s resources just to digest them properly.

If you want to get really specific, you can get a bio-individual report based on blood work that will show you exactly which nutrients are throwing your body out of balance long before you feel the physical ramifications. Companies like Inside Tracker, whose techniques have been used by professional athletes for years to help them target their nutrition for performance, are making a big splash in the health and nutrition world by opening their services to the public.

One more tip: decide before you go for a run what you are going to eat after your run. In your head, plan your post-run meal and do it before the rungry takes over your brain. You will need protein, minerals, carbohydrates, and fats. All should come from whole food sources. That way, when you plop down in the seat at the dinner next to your running buddies, you already know that your plate is going to include some eggs, oatmeal, fruits, and vegetables. Not just pancakes and french toast.

Reason 2: You are hitting the sugar hard, and you don’t even realize it.

At every marathon, you will find two things being liberally handed out at water stops along the course; sugary sports drinks and sugary gels/blocks/beans. It’s so ingrained in running culture that you need to replace carbs while running to avoid “bonking” during a race or training run that you may not think twice about chugging down a sports drink that you normally wouldn’t touch. Just because you are running doesn’t mean eating sugar won’t cause blood sugar highs followed by intense crashes. Our insulin/leptin system operates in a delicate balance.

What you can do about it:

Find better sources of race-day nutrients and try as hard as you can to avoid sugar crashes.

Before your long runs, eat a solid breakfast complete with fat, protein, and “slow carbs” like oats or sprouted grain bread. Can’t run on a full stomach? Wake up early enough to allow time to digest a bit before hitting the pavement for a long run. Pack easy to digest whole foods and drinks to consume at regular intervals such as dried fruit, spirulina tablets, mineral salts, coconut pieces, raw coconut water, “bulletproof” coffee, or even dark chocolate. Consuming a small amount of food at regular intervals gives you a better chance of maintaining even blood sugar rather than waiting until you crash.

Reason 3: You are overtraining, under-recovering, over-stressing, and thus over-taxing your endocrine system.

The intense tax training for a marathon puts on your body’s resources, especially with regard to stress, blood sugar, fluids and electrolyte balance, is an endocrine disaster waiting to happen. And for many people, especially women, whose bodies depend very intimately on the careful balance of changing hormones throughout their monthly cycle, it absolutely is.

It’s not just tackling long miles with inefficient methods of replacing electrolytes. How many runners out there are guilty of the following:

Regularly forgo the necessary 7-9 hours of sleep in order to get up early and knock out a run before work (Guilty!)

Ignore stress in our lives or “power through” by adding extra “stress management” work-outs. (Guilty!)

Exercise MORE, not LESS, when you feel your performance slipping. (Guilty!)

Register for race after race after race with little to no recovery time between running one race and beginning training for another. (So, so, so guilty!)

What can you do about it:

Have a smart training plan and an even smarter recovery plan.

Start by considering that you may not need to train as hard or as much as you think you do. New evidence suggests that training up to the revered “20 miler” before a marathon can actually do more harm than good, especially for those who run 9:00+ minute miles. Some scientifically proven methods, such as those coming from the Furman Institute of Running and Scientific Training, suggest that all you need are three very specific run workouts per week to achieve your best race. Do some research and train with intelligence, not frequency.

Make sure you get that average 7-9 hours of sleep per night! Lack of sleep contributes to disruption of the endocrine system and significantly impacts physical recovery. Protect that sleep time like a mama bear with her cubs.

Address your chronic stress and do not underestimate its ability to ruin your health. Stress can cause hormone imbalances with as significant an impact on your body as nutrition.

Recovery, recovery, recovery! Schedule in and take recovery days. If you’re feeling run down despite your scheduled recovery days, skip a workout and take an extra recovery day. After training for a big race, take a few months off from endurance training and back off of the long distances. If you’re a marathon runner, choose two marathons per year to train for and make them about 6 months apart. If you’re a race junkie, pepper smaller, shorter distances in between so you can get your bling-fix without running your body ragged.

In conclusion:

Before blaming yourself for packing on the pounds, or assuming that it is your fault that you gained weight by not training hard enough or trying hard enough, consider that you may just be experiencing your body’s natural reaction to being depleted of resources! Get curious about your weight gain if it doesn’t make sense to you. Before abandoning the sport that you love, realize it is possible to train a bit smarter going forward. Keep the faith, love yourself, and treat your body with kindness, sleep and good nutrition.