Marathon Training for Weight Loss

Male runner stretching in shade.
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How far would you go to get the body you want? If the answer is 26.2 miles, then this article is for you. Many exercisers use marathon training for weight loss. But running to lose weight doesn't always work. You have to know how to lose weight during training if you want to cross the finish line with a leaner, fitter body.

Weight Loss During Marathon Training

You might be surprised to know that many new marathoners don’t lose any weight during training. In fact, many people actually gain weight when they train for a marathon. Surprised? The situation is more common than you might expect.

Scan any running blog or online forum and you'll find countless posts written by frustrated runners who (reasonably) expect to slim down as they slog through their weekly miles. But instead, race day arrives and they are no leaner than the day that they started training. So what's the problem?

There are several issues that come into play when you combine marathon training and weight loss. These issues may explain why you can't slim down when running. Understanding these factors might also provide a sense of relief (don't're normal!) and lead you to a strategy for getting the results that you want.

Training May Increase Hunger

There is some scientific evidence showing that intense exercise and running, in particular, can lower the levels of hunger hormones and even lead to a decrease in food intake.

One study, published in the Journal Nutrients found that when long-distance runners completed a 20 kilometer run their levels of the hunger hormone ghrelin decreased and they consumed less food as a result. But, many studies, including this one, are conducted on trained athletes, not on newer runners, overweight runners, or obese runners.

Other researchers have stated that "the effects of exercise on hunger sensations and food intake are fairly controversial and depend on the intensity and duration of exercise." The bottom line is that exercise doesn't always have the same effect from person to person—it can make some people hungry and others less so.

If you crave food after you've completed your miles, you're not alone. Countless runners claim that long workouts make them run for the fridge, even if the published science suggests otherwise.

Nighttime Feeding Increases

Runners often train at night after work. While it doesn't seem unreasonable to start your workout at 7 or 7:30 pm, it means that you don't finish until 8:30 pm or 9. The result? You might eat later at night.

There is some evidence suggesting that nighttime feeding is associated with increased body fat. Also, it's possible that you won't make the best food choices when you are tired after a long day. The combination of a late meal and less-than-healthy food choices may increase your chances of weight gain.

Running Provides Rationalization

How many times have you finished a long run and then felt justified to eat an indulgent treat or high-fat meal? If you've done this often, you're not alone. Runners often joke about "earning" a burger, a beer, or some other high-calorie extravagance.

While almost no one would disagree that long sustained efforts are worthy of a reward, if you use this common running rationalization too often, you may end up consuming more calories than you burn when training.

Training May Decrease NEAT

Non-exercise activity thermogenesis (NEAT) is the name researchers use to define the energy (calories) expended from all of your daily movement that is not exercise. NEAT accounts for up to 60% or more of the total calories you burn during the day. But there is wide variation in that number.

People who take the stairs, walk to the market, stand or walk around in the office, cycle to work, or simply fidget more often burn more calories from NEAT. Those who have sedentary jobs, watch more television and rest throughout the day burn fewer calories from NEAT.

Your marathon training can make you more tired than normal. As a result, you may be less active during your non-exercise hours. In short, you might burn more calories from exercise, but fewer calories from NEAT. The loss in calories burned from NEAT might be substantial enough to impair weight loss or even cause weight gain.

Exaggerated Caloric Expenditure

It is easy to overestimate the number of calories that you burn during a workout. In fact, studies have shown that, as a general rule, we are not good at guessing the number of calories we burn during exercise.

One study published in the Journal of Sports Medicine and Physical Fitness found that normal-weight adults estimated their calories burned during exercise to be three to four times the actual number. Further, when asked to precisely compensate for their exercise expenditure with food intake, the resulting energy intake was two to three times greater than the actual measured expenditure of exercise.

Even if you wear a fitness monitor that tracks calories burned, the number can be inaccurate. Research has shown that while trackers are generally good at measuring heart rate, number of steps, distance, and sleep duration, they tend to be less accurate at determining calories burned during exercise.

How to Lose Weight While Marathon Training

Losing weight while training to run a marathon is possible. But it’s hard. In short, you've got two competing goals: one pushes you to eat more and the other nudges you to eat less. If you take on both challenges at once, you'll need a solid strategy for success.

Use these tips to eat well, train smart, and perform at your best during training.


It is possible to work towards both your weight loss goal and the marathon goal at the same time, but you should prioritize one. Decide if it is most important to lose weight or most important to complete your marathon.

Making the decision may depend on your current weight and state of health. For example, if you are overweight or obese, losing weight may help you run a marathon more comfortably and efficiently. Weight loss may also help to prevent injuries. In this case, losing weight would be a smart priority. If training gets in the way of meeting weight loss goals, then postpone the marathon and reach a healthy weight first.

But if you are heavier than you'd like to be, yet not overweight, running may help you to be more comfortable with your body. You might learn to love your body the way it is, based on what it can do, rather on what it looks like. This boost in confidence might help motivate you to reach your healthy weight loss goals.

In this case, marathon training would be a smart priority. If weight loss gets in the way of reaching your running goals, then postpone it. After the marathon, you may decide that you don't need to lose weight after all.

Meet Your Macros

Be sure to get balanced nutrition during training. Avoid diets that eliminate or severely restrict a food group, especially carbohydrates.

Your best nutritional plan during training might vary from recommended guidelines. In fact, different coaches, nutritionists, and trainers have different opinions about how to balance your fats, proteins, and carbs. But many coaches swear by a 20/20/60 approach.

Try to consume 20% of calories from fat, 20% from protein, and 60% from carbohydrate. You may find that you need to tweak the numbers slightly, but the 20/20/60 plan is a smart place to start.

Choose Quality Carbs

Choosing high-quality carbohydrates will not only help you to fuel your runs more effectively, but it can also aid in weight loss.

Try to avoid refined grains and processed foods. Foods that contain added sugars, excess sodium, and saturated fat (usually called empty calorie foods) will leave you hungry and too tired to run. Instead spend most of your carbohydrate allowance on filling and nutritious whole grains, fruits, and vegetables. These foods provide energy as well as important vitamins and minerals.

Keep in mind, however, that immediately before and during your long runs you need quick energy. On these occasions, lower fiber foods are generally recommended to avoid stomach upset.

Time Your Food Intake

If you're an evening runner and you've fallen victim to the late-night-eating habit, consider moving your biggest meal to the middle of the day. By eating most of your calories in the afternoon, you fill up on healthy foods and give your body the energy it needs in time for your workout.

You can also use meal prep strategies to improve your food timing. Prep healthy pre- and post-run snacks once each week and have them ready to go when you need them. Plan meals in advance and pre-cook as much as possible so you aren't tempted to grab fast food when you're hungry.

Incorporate Strength Training

Running every day will wear your body (and your brain) down quickly. Take a few days each week to focus on strength training.

Doing bodyweight exercises or training with weights can help reduce the risk of running injuries. Also, it is not likely to make you as hungry as running. And most importantly, strength training builds muscle and muscle helps you burn more calories for fat loss.

Choose Healthy Rewards

Choose non-food treats to reward your efforts. For example, after a long run, you might get a massage. After a tough hill workout, get a pedicure or see a movie with a friend. By finding healthy ways to celebrate your efforts, you honor the running achievement without derailing the weight loss attempt.

Get Expert Help

Some runners can schedule their runs to train for a marathon. Some people who are trying to lose weight can schedule nutritious meals. But juggling both at the same time is tricky. So why not ask for help?

Seek the guidance of a registered dietitian with knowledge and expertise in sports training or running. They can provide you with a meal plan, recipes, and tips to make your nutritional plan easier to follow.

Your nutrition professional may also be able to help you sort through your goals. If marathon training and weight loss start to take over your life, it may be time to revisit your priorities and see which choice is more likely to promote better health and wellness.

A Word From Verywell

Training for a marathon is an exceptional accomplishment. Completing each day’s mileage in spite of typical daily distractions takes mental endurance, self-discipline, and focus. Losing weight requires an identical effort. If you choose to take on both challenges at the same time, you’ve got to double your investment to see results. But the payoff is extraordinary. Use these tips during your marathon training for weight loss and a strong performance on race day. 

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