Frequently Asked Questions About Running and Weight Loss

Over the course of 2020, I lost about 40 pounds and I kept it off. This wasn’t possible just because of running. But without running, I don’t think I would have been this successful. So let’s talk about running and weight loss.

Running isn’t a panacea or a magic bullet. It won’t magically help you lose weight overnight. Once you understand the role that running and exercise have to play in managing your weight, though, it can be a great asset.

Unfortunately, there are a lot of misconceptions about running and people often don’t understand its role in weight loss. So I’ve tried to gather up a bunch of frequently asked questions about running and weight loss and answer them here.

And if you have a question that I haven’t answered… please scroll to the bottom and leave a comment. I’d love to add it to this FAQ!

A scale with potatoes on one side and nothing on the other side. Diet and exercise are equally important for weight loss.
Neither running nor dieting is “more important.” They both have a role to play in weight loss and weight management.

What’s More Important for Weight Loss – Running or Dieting?

If you ask people how to lose weight, you’ll often get a simplistic response. It’s as simple as calories in, calories out. If you take in fewer calories than you burn throughout the day, you’ll end up losing weight. If you take in more calories than you burn throughout the day, you’ll end up gaining weight.

This is true, to an extent, but there’s a lot of complexity hidden behind that answer. If I could only pick one of the two, it would be dieting and monitoring my food intake. Running, by itself, probably won’t lead to significant weight loss.

But these two things together are more than the sum of their parts. Many people lose weight and quickly gain it back. The problem isn’t weight loss, per se, it’s weight management. And in the long term, exercise – like running – is just as important for weight management as what you eat.

Does Running Help You Lose Weight?

Yes, it absolutely does.

Weight loss is, generally speaking, about using up more energy than you consume. You can limit what you take in or you can increase what you use up. Ideally, you’ll do a little bit of both.

Running is a particularly efficient way to burn calories. Jogging a mile will burn somewhere between 100 and 150 calories, depending on a few factors. Taken in isolation, that may not seem like a lot. But when you zoom out and look at things on a weekly or monthly basis, it adds up.

Let’s say you run about three miles a day, five times a week. That’s a commitment to running, but it’s not a crazy amount of time or distance. That alone would contribute about two pounds of weight loss per month. Combine that with a moderate reduction in calories consumed, and you can easily lose four or five pounds a month – a healthy, long-term goal.

For more on this, check out this article: Is Running the Best Kind of Exercise for Weight Loss?

Does Running Burn Fat?

If you’ve ever been to a gym and used an exercise machine, you’ve probably seen something about the “fat-burning zone.” This might lead you to believe that some exercises are good for burning fat and others aren’t.

In a literal sense, that’s true. The body has two main sources of fuel – stored body fat and muscle glycogen (sugar). Short bouts of intense exercise will typically use more sugar than fat. Longer bouts of easy or moderate exercise will rely more on fat.

An easy run – i.e. jogging at a conversational pace where you heart rate is only moderately elevated – will let your body rely mostly on fat as a source of fuel. So in a literal sense, easy running will burn fat.

But when you look at the big picture, it’s a bit of a shell game. If you don’t use up your stored glycogen, any excess sugar that you eat is stored as fat. But if you do use up to glycogen, that sugar will be stored there, and it won’t be stored as far.

It’s the big picture that matters – both how your body uses up energy and how you fill it back up when you eat.

Does Running Burn Belly Fat?

If you’re looking for an easy way to get rid of your belly fat, I hate to break it to you. But there isn’t one.

This is known as the myth of “spot reduction.” There are lots of misconceptions around exercise that there is a way to target fat loss and reduce fat in a particular part of the body – i.e. the belly, the hips, the thighs, where ever you don’t want it.

If you go for a nice long run, your body will certainly metabolize some stored body fat and burn it off. But there’s no way to target that fat burn in any one place. If you want to burn off that beer belly, you’ll have to commit to long term weight loss.

The stored fat might be most noticeable in your mid-section, but as it slowly disappears all over your body that belly will shrink. Remember: slow and steady wins the race.

Is Running the Best Kind of Exercise for Losing Weight?

There are a lot of reasons to choose running as your exercise method of choice.

It’s cheap and it’s simple. You probably have all the gear that you need to get started, and you don’t need a gym membership to start running on your local streets or your local hiking trails. You don’t need any particular skills to be able to run, just some patience and some commitment.

It also straddles a fine line between efficiency and intensity. Walking is a great form of easy exercise, but in the same amount of time it will burn a lot less energy. More intense activities might burn more calories per minute, but you usually won’t be able to maintain them for very long. Once you’ve built up some endurance, you can easily run for 45 minutes to an hour.

Running is certainly no holy grail. But if I had to suggest one form of exercise that would benefit the most people, it would be running.

How Much Should I Run a Week to Lose Weight?

“How much should I run?” is a loaded question. The answer can depend a lot on your goals.

Competitive runners can easily run 50, 60, or 70 miles a week. The most competitive runners will put in over 100. On the other end of the spectrum, someone looking for the basic health benefits of jogging could get by with about 10 miles.

If you’re running for weight loss, you’ll end up somewhere in the middle. You want to run enough that it makes a difference, but you also don’t want to run so much that you break yourself down.

A good goal to work towards is 30 to 45 minutes per run. You should probably start out with 3 or 4 days a week, but aim for at least 5. You can increase this over time, but I wouldn’t run more than 60 minutes a day.

How Many Miles Should I Run to Lose Weight?

There are two ways to think about this – on a daily basis and on a weekly basis.

On a day that you run, you should try to run at least three miles. It might take a little time to get to this point, but it’s certainly manageable for anyone. It’s enough to burn a few hundred calories and make a significant difference in your overall caloric expenditure.

You can increase this over time, but you should stop when you hit five or six. After that, you’re getting into dangerous territory.

Likewise, you should keep an eye on your total weekly mileage. There’s nothing wrong with running every day, per se. Lots of people do it. Runners call it streaking.

But if you can run six miles in a given run, and you decide to push yourself to run six miles every day of the week, you’re putting in a total of 42 miles per week. That’s a lot of running, and it would be enough to make someone a competitive amateur runner. And if you’re trying to lose weight, it’s also probably enough to hurt yourself.

As long as your goal is weight loss, I’d cap out at no more than 25 to 30 miles per week. If you find you love running and you want to get more competitive, that’s great. But you should wait until your weight has stabilized before you increase your volume too much.

For more, see this article: How many miles should I run to lose weight?

Is There Such a Thing as Running Too Much?

Yes. Especially if we’re talking about weight loss.

Elite runners will put in more than a hundred miles a week. So it’s not like you can’t run that much.

But when your goal is weight loss, you need to take a measured, long term approach. For one thing, if you woke up one day and tried to run a hundred miles in a week, you’d probably hurt yourself pretty quickly.

And even if you managed to do it for a while, if you’re not consuming enough calories your body will start breaking down. Assuming a normal-ish diet of 2,000 calories per day, you’d still be losing 3-5 pounds per week. That’s just too much to be healthy.

There’s a new term that’s recently been coined – exercise bulimia. It’s an obsessive compulsion to exercise and burn off every bit of food you eat. It’s a form of eating disorder, and it’s not good for you.

There’s surely some variation in how much an individual should run. But if your goal is weight loss my suggestion would be to strive for 10 to 20 miles per week, and definitely no more than 25 or 30. Once you go beyond that point, you’re probably getting into unhealthy territory.

Should I Focus on Speed or Distance When Running to Lose Weight?


If you want to estimate the amount of calories burned while running, there’s a pretty direct correlation between distance and calories. Speed can impact it a little bit, but not by much. To burn more calories, you have to run farther.

As an example, let’s say you’ve worked up to be able to run 3 miles in 30 to 35 minutes. It may seem tough, and the first few runs will be hard, but in a few weeks you can probably stretch those 3 miles to 5 miles at the same pace. You’ll increase the amount of calories burned by 66%.

Or, you could focus on speed. You spend a month doing some workouts and you shave a few minutes off your time. Now, you can run 3 miles in 27 minutes. You’re burning the same amount of calories, and you’re doing it in slightly less time. But is that helping you lose weight?

Over time, you will get faster. But if you focus on speed in the short term, you won’t be able to increase your distance. As a result, you’ll limit the amount of calories you can burn – and limit your weight loss.

If you find that you love running and you want to get more competitive, that’s great. But lose the weight first, and focus on your speed once you’ve built up a base of running and found a stable weight.

A large breakfast. You don't need to eat before you run in the morning.
You don’t need to eat breakfast before you run in the morning. In fact, eating a big breakfast may sabotage your efforts to lose weight. Feel free to run on an empty stomach.

Should I Run on an Empty Stomach for Weight Loss?

Personally, I almost always run in a fasted state. I wake up, have a cup of coffee, use the bathroom, and hit the road. For an easy run – even a long one of ten to twelve miles – you don’t need to “fuel up.” This is a common misconception.

From a weight loss perspective, there’s also some advantage in running on an empty stomach. Your body will have used up some of it’s stored sugar (muscle glycogen) over night, and you’ll burn more stored body fat while exercising. This is (part of) the theory behind intermittent fasting

When you refuel later in the day, your body will fill up those glycogen stores. But if you’re controlling your intake, you won’t necessarily be replacing that fat that you burned. If, on the other hand, you over eat the rest of the day, it’s a moot point. And you’ll end up right back where you were.

On a larger scale, this may not matter much, though. Intermittent fasting is a craze these days, and I think it’s a little over-hyped. If you normally eat breakfast, and you want to eat it before you run, it probably won’t completely sabotage your weight loss.

As long as you don’t eat extra food for the specific purpose of “fueling” your body. That’s a definite no-no and that will absolutely prevent you from losing weight.

Why Does My Weight Drop So Much Right After a Run?

When you step on the scale, you see a single number. This over simplifies things to a certain extent and the daily fluctuations of that number can be misleading.

If we break that number down – in a simplistic way – you can think if your body as being four things – a) structure (bones, ligaments, organs, etc), b) muscles, c) fat, and d) water.

The structure of your body isn’t going to change much, so ignore that. If you work out with some weights, you might increase your muscle mass, and that’s a good thing, but it’s probably unlikely in the short term if you are actively losing weight.

The main fluctuation in your weight is the other two parts – fat and water. In the long term, to lose weight, you need to burn off some of that body fat. It’s your body’s stored up energy.

But in the short term, your body gains and loses a lot of water throughout the day. When you for a run, this happens in two ways. First, you probably sweat a lot. Second, you use up some stored muscle glycogen, and glycogen is stored with water. Once the glycogen is gone, the body gets rid of the water.

So if you go for a nice run and you weigh yourself afterwards, it’s not unusual to hop on the scale and “lose” a few pounds. It’s not magic; it’s water.

No, you didn’t “burn” three or four pounds. And yes, you should drink some water.

A table full of pizza. Just because you go for a run doesn't mean you can eat anything you want and still lose weight.
Even if you run for an hour, you shouldn’t eat an entire pizza. Sorry.

If I Run For an Hour, Can I Eat Anything I Want?


Running a mile will burn about 100 to 150 calories. If you run for an hour at an easy pace, you’re probably running five or six miles.

In terms of calories (500 to 750), this is a significant amount. But if you go overboard, you can easily eat more than you burned on that run.

To put that in perspective, let’s say you head to Chipotle to celebrate. I just spec’ed out a nice Chipotle burrito – with carnitas, brown rice, black beans, cheese, sour cream, guac, and corn salsa – and it weighed in at 1405 calories. If you wash it down with a fountain soda, that’s another 2-300 calories.

This is why people say you can’t out run a bad diet.

But keep everything in perspective. Let’s say on an average day, your body burns 2,250 calories. Your hour long run increased your overall calories burned to 3,000.

If you maintain a deficit of about 500 calories – to be on pace to lose a pound per week – you can still eat 2,500 calories. By contrast, without the run, you’d have had to eat 1,750 calories.

The amount you can eat in a day increased by 40% – and that’s significant. It’s just not unlimited.

Do I Need To Eat a Lot of Carbs If I’m Running for Weight Loss?


If you think of a “runner,” you probably think of someone who eats a ton of pasta, breads, and other carbs. There’s a popular notion that runners need to fuel up and carb-load before every run.

And if you’re a collegiate distance runner, running 75 miles a week and racing every weekend, that might be true. Competitive distance runners are typically very skinny, and they end up burning a lot of energy training, so they need to eat a ton to recover and stay healthy.

But that’s not you. You’re an average person looking to lose weight.

Think about this. Every pound of body fat has enough energy stored in it for you to run a marathon, roughly speaking. That’s 26.2 miles.

If you’re trying to lose weight, you have a few pounds of body fat to spare. And there’s no shame in that. Embrace it – and know that you have all of the fuel you need right there, waiting to be unleashed.

Yes, you should eat a well rounded diet, with protein, minerals, and vitamins. But for the rest of it, it doesn’t really matter whether you eat carbs, fat, or protein.

Monitor your intake and keep it under control. But definitely don’t “carb load,” thinking you need extra energy to run. That’s a fast track to failure for weight loss.

What Other Questions Do You Have About Running and Weight Loss?

The bottom line is that running is a useful tool in your weight loss and weight management toolbox. It’s not a magic bullet, and it won’t help you lose 20 pounds overnight.

But in the long term, it’ll help you burn enough calories to get rid of your unwanted weight. And it will also help you keep it off, since you’ll be able to eat a reasonable amount of food without putting it back on.

I’ve tried to answer many of the common questions – and address some of the misconceptions – about running and weight loss. I’m sure I’ve missed a few.

For something more comprehensive, here’s a guide to running for weight loss.

So if you have an other question, drop it in the comments below. I’ll add it to the list the next time I do a revision.

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