Running To Lose Weight Is A Terrible Idea

It's a pitfall of too many dieters: They decide to "get healthy" — by which they mean "lose weight" — so they start eating salads and going on runs.


Experienced runners everywhere hear this and cringe. Running to lose weight is a terrible idea.

Weight loss is not only an appearance-oriented reason to run that likely won't provide enough intrinsic motivation to last, but it's also a misguided motivation. Running does not efficiently, if ever, make you lose weight.

Running is what exercise professionals like to call "steady-state cardio." This is cardio that lacks the intensity to produce an extreme response by the body; you can tell this because your heart rate remains relatively stable throughout the run.

Your body is smart: It goes first for the stores of energy it saves from intra-muscular stores of fat, circulating free fatty acids, muscle and liver glycogen, and blood glucose, all of which it uses to fuel your daily activities and lower-intensity conditions of exercise.

So you're not actually burning fat with exercise until your body needs more energy much quicker — during high-intensity exercise. When your heart rate is at an extreme high, your body recognizes it's under extreme conditions, and it dips into its precious, last-resort stores of fat.

If you were to go on interval training runs, where you ran sprints or trudged up hills, you might enter this actual fat-burning zone.

But if we're talking normal running, you would have to run for hours and hours to run out of alternative sources of energy (or eat dangerously little, which we do not recommend you do). And even if you do run for hours and hours, it might still not work to dip into your fat stores and lose the weight you want to.

I've known people who have trained for a marathon with the intention of shedding pounds. During their training, I watched them run mile after mile and become increasingly agitated because they continued to gain weight as the runs got lengthier.

This (understandable) frustration comes from a misunderstanding many people hold about health. "The healthier I get, the thinner I'll be!" False. Sometimes, the healthier you get, the more weight you put on. Your body's just trying to survive, after all.

Allow me to explain. When you run, your body expends a great deal of energy — especially when you're running long distances. Here's something your body doesn't want to be: tired.

There are a few different places your body searches for its energy: your food, your fat, and your muscle. First, it's going to plow through your energy from food. If you're trying to lose weight, it's probable that you're eating at a calorie deficit, i.e., expending more energy than you consume. So you're likely not eating the extra calories you would need to support those runs. So when it's out of that, it has to choose: Is it going to dip into your fat or your muscle?

It will likely dip into your muscle. Your body's on preservation mode. What does it need more, the energy stored from fat or the muscle that burns fat?

Try driving a car on just a few droplets of gas at a time. That's the mechanical equivalent of trying to force your body to function without gathering an energy reserve. Now imagine that a car was smart enough to save gas for later. What do you think it'd do?

Your body saves fuel for later. It puts on weight — saves some gas. And it plows through the unnecessary muscle (running requires a minimal amount of physical strength). So as you get better at running, as you practice and run longer distances, you might just get heavier. And healthier. You'll gain endurance, build a few key muscles in your legs, improve mental and physical stamina. You'll be more capable, better equipped to outrun an attacker, and have a much stronger heart.

You might just get healthier and heavier. At the same time.

Now, that's not to say you shouldn't run. If you want to run, by all means — run! Just don't do it for weight loss.

There are so many more valuable reasons to feel proud of running a marathon or dedicating yourself to training that have nothing to do with fat loss or whether you can fit into those size 4 jeans. Here are a few:

  • Get in better touch with your body.
  • Get healthier and stronger (though maybe heavier).
  • Spend meditative time outdoors.
  • Fight depression.
  • Alleviate anxiety.
  • Join a new and uplifting community of other runners.

And there are many more. Everyone's reason to run is different, but they should all have one thing in common — they shouldn't involve running to lose weight.