Why Training for a Marathon is a Terrible Weight-Loss Strategy

Running is a fantastic way to lose weight, but specifically training for a half marathon or marathon is often a one-way road to frustration and failure when it comes to dropping pounds. In fact, people who train for marathons often report GAINING weight in the process! Here are 4 reasons why that happens.

1) Endurance running causes big-time food cravings.

Unless your input nutrition during training is nearly perfect in terms of getting the correct ratios of carbs, protein, fat, and the right balance of electrolytes, intense physical activity causes your body to crave whatever it happens to be missing. People short on carbs will crave sugar, people short on electrolytes will often crave salty snacks, and people who are short on calories in general will crave food.

The result, for most athletes, is an over-response. You might only need a teaspoon of salt, but end up eating a whole bag of pretzels. You might only need a few grams of carbs to balance out your glucose levels, but end up eating a pile of sugary snacks.

For me, the end of a distance run leaves me ravenously hungry for literally any kind of food about 24 hours later. In fact, if I’m not carefully watching my food intake, I can easily consume an extra 1,000 to 2,000 calories above and beyond that I actually need just by giving in to that general craving for food.

Unless you’re the kind of person who’s strictly counting every calorie you eat, your body is going to lie to you about how much food it needs and you’re probably going to over-eat and gain weight.

2) Excessive cardio can actually block fat burn and slow your metabolism.

High amounts of cardio stimulate the production of the stress hormone known as cortisol. Unfortunately, cortisol production also blocks fat burn. (From a purely evolutionary perspective, this makes sense. When the body goes into panic mode, the first biological instinct is to preserve our fat-stores in order to conserve energy).

So where does the energy come from if you’re eating at a caloric deficit (so you can lose weight) and you run like crazy? Your body reacts by slowing your metabolism to compensate. Now you feel tired and sluggish, even when you’re not running because the food you eat is more likely to be stored as fat, rather than used as energy.

It’s a viscous cycle!

3) You can’t eat at a caloric deficit and expect to perform well in a marathon.

Running is hard enough without having your body working against you — but if you’re eating at a caloric deficit (which is required, if you intend to burn fat), then your body is, by definition, performing sub-optimally.

Eating the correct balance of calories, carbs, fats, and protein is the secret to achieving optimal running performance. Unfortunately, that’s mutually incompatible with dieting for weight loss.

4) You can’t out-exercise your bad diet

Most athletes training hard for a marathon get caught up in the idea that their training somehow justifies the ingestion of junk-food. Unfortunately, the math doesn’t work in your favor. The amount of running required to burn off a steady diet of snacks, treats, and unhealthy food isn’t realistic.

Don’t believe me? Check out this article.

The better strategy?

First, try eating to run, instead of running to eat!

Second, use running as a tool to burn fat, but don’t focus on the half marathon, or the marathon until you’re closer to your goal weight. Try to keep your weekly running volume low enough that you won’t trigger the problems mentioned above (absolutely no more than 12 to 15 miles per week!)

To drop the weight, you should eat 500 to 1000 calories per day less than what you would normally need to maintain your weight. This will give you an (average) weight loss of about 1 to 2 pounds per week. (Don’t get discouraged if the weight doesn’t come off at a steady rate, especially if you’re female. The “Whoosh Effect” is a real thing!)

Once you reach your goal-weight, it’s time to up the volume and get serious about endurance training! Increase the calories to 250-400 calories per day OVER your maintenance number (yes, eat that EVERY day), and you’ll be training at peak performance while eating tons of food!