Your Ultimate Guide to Running and Weight Loss

You can lose weight just by running if your routine boosts your activity level beyond what it was before. So if you never exercise and you start runningeven just around the block every day or running for 30 minutesyoure going to burn more calories and drop some weight (unless you fall into the trap of eating extra. More on that in a minute).

But when that amount of running becomes routinemaybe you run the same three miles on the same three days every week for months on endyour weight will stay stable. To be clear: Youre still burning calories by running, but youre not burning more calories than you did before. So if you run the same and eat the same, youll still weigh the same.

To burn more by running, you need to change something up: Maybe you go longer, maybe you go faster during certain sections ( try these get-faster workouts ), maybe you replace some flats with some hills. Any shift (that anything more than you did before thing) can boost calorie burn again.

How you can lose even more weight by running

Beyond changing up your running, experts all say that if you really want to lose weight by running, you need to think about what you eat.

Sometimes that comes naturally: often when people go from a sedentary state to moving more, they feel good about taking care of themselves and that might translate into eating better, says Leslie Bonci, a sports dietitian for the Kansas City Chiefs and co-author of Run Your Butt Off.

But the honeymoon phase is not forever, she cautions. What started as a banana after a workout can spiral into a high-calorie coffee beverage and a pastry on the way home from that run.

Too many runners overcompensate with calories after their runs, thinking that they earned it, says Jason Karp, Ph.D., chief running officer of Run-Fit and author of Run Your Fat Off . The thought of a big plate of pancakes with boysenberry syrup and a chocolate banana smoothie is often enough to get some runners through another few miles of a long run. Which ends up giving you more weight to carry around on your next run (not fun). A recent study in the American Journal of Clinical nutrition confirmed that new exercisers tend to overcompensate with calories when they work out, losing less than expected.

People tend to forget that running isnt a tremendous calorie burner. You burn about 100 calories a mile, Bonci says. Thats whether you go slow or fast. (If youre fast, you just run a lot more miles in 60 minutes than slower people do.) So if youre mentally estimating how many calories youre burningand replacingthink in miles, not minutes. That 3-mile run might have been hard, and even if you crushed it much faster than usualits still only 3 miles. You finished faster, but didnt burn more (sorry).

How to avoid the running/weight gain danger zones

To prevent overeating when youre in a running groove, you have to be smart about what youre eating before, during and after that workout.

Before a run . For a 45-minute run, you dont need to have something ahead of time, says Bonci. A two-hour training run is differentyou need to have some fuel in the tank. But if youre only exercising for an hour, theres no need to have anything other than water.

During the run . People only need to fuel during long runs if they are training for a marathon or ultramarathon. Often, people consume lots of calories from sports nutrition products during shorter runs and then wonder why theyre not losing weight, Karp says.

After the run. Start with a big glass of water. That helps you rehydrate and takes up stomach share, says Bonci, which can help you avoid inhaling everything in the kitchen at once. If you want something before you shower, think of it as an hors doeuvre, then shower and come back and have a meal in a more relaxed way, she says. Think of water as the shooter and the chaser is a little bit of something to eat.

Ideal for post-run: I like the idea of eating something that requires a utensil, because then it at least takes a bit longer to eat, Bonci says. Yogurt with granola can be good, because even if youre tired from running, most people have enough energy to lift a spoon to their mouth.

How much weight can you lose by running?

Lots. Dustin Worth, for instance, got inspired to run when his wife completed a marathon, and he lost 20 pounds in just a month of running on a treadmill in their basement. That was when he was 270 pounds, and his running and healthy eating habits turned him into a shredded 170-pound guy now ( see his whole story, with photos ).

Dustin Worth BusinessInsider USA Images

And then theres David Myers, who, at more than 350 pounds, started walking. Then he started running, and today, hes 130 pounds lighter . And Stephane Doiron , who grabbed his running shoes when he realized he couldnt keep up with his son, whom he was pushing to excel in strength conditioning for his hockey team. I remember at first, I could barely run a minute without stopping to regain my breath, he says. Today, he regularly runs 10Ks and has dropped 55 pounds. You dont have to run far to make running work for you. Just get out there and get after what you want from it.