How Many Miles Should I Run a Day to Lose Weight?

Running burns calories and can help you get leaner, but you shouldn't overdo it. If you go overboard, you can get injured, which will make your quest to lose weight much more difficult. The key is to find a sweet spot between too much and too little.

Losing weight can seem like an uphill battle. Exercise and diet are the big things you can control. Adjusting each can help you burn more calories than you take in each day. When you burn more calories than you consume, you enter a state known as "negative energy balance."

You can't lose weight unless you're in a negative energy balance, so that's the most important thing to keep in mind when you're determining how many miles to run per day. While this activity helps you burn calories, reducing your food intake contributes to a negative energy balance as well. If you eat clean and watch your portions, you don't need to rely solely on exercise for weight loss.

A research paper published in the August 2016 issue of Obesity Reviews compared a calorie-restricted diet to aerobic exercise, like running. The diet was overall more effective for weight loss, but exercise helped subjects lose more fat around their organs.

The number of calories you burn while running depends on many factors. The most important factor, by far, is how hard your muscles are working, according to a June 2017 review published in Frontiers in Physiology. As the researchers note, the amount of energy that muscles use during a run determines how many calories are burned, and that factors like gender aren't as important.

Read more: Runner's Caloric Intake

A major factor in how hard your muscles work is your body weight. The more you weigh, the more work your body has to do to propel you forward. Harvard Health Publishing estimates that the energy expenditure of a 125-pound person running an eight-minute mile is 375 calories. That number goes up to 465 calories if they're 155 pounds and 555 if they're 185 pounds.

The speed at which you run and the incline matter as well. A small study published in the October 2019 edition of the Journal of Sports Sciences has found that running on an incline activated leg muscles to a greater extent than running on the decline slope, leading to a higher increase in the number of calories burned. That's why you need to take into account more than just the total number of miles you're running.

Another factor that may affect how hard you're working is the surface you run on. Another small study published in August 2016 in the Journal of Sports Sciences suggests that running on a stiffer treadmill may increase energy expenditure.

Your technique can also play a role, according to a small study featured in Medicine and Science in Sports and Exercise in July 2017. Researchers have found that bending at the knee and hip more during a run made the subjects use more energy. This is useful for runners who want to be more energy-efficient.

Read more: Does Running on the Beach Really Burn More Calories?

Running until you lose weight might not be the best strategy. Overuse injuries are shockingly common among distance runners. A May 2018 study published in the American Journal of Sports Medicine found that over the course of a year, 66 percent of runners sustained at least one injury.

Women and those with higher body weights who participated in the above study were more likely to be injured. The chances that you get hurt from running are fairly high, and if that happens, you may not be able to exercise for weeks or months. For this reason, it's smart to add other forms of exercise to your routine and engage in cross-training.

Adding resistance training, yoga or aerobic activities like swimming to your workouts may reduce injury risk. This strategy takes away some of the stress of running and lets your body recover. You still burn calories while you do other forms of exercise, and you can strengthen different muscles that running engages to a lesser extent.