Running is hands-down one of the best exercises you can do to lose weight. By torching an average of 100 calories per mile, pounding the pavement -- or treadmill -- can help you blast calories, shed inches and improve your overall health. By combining it with a proper diet, you can expect to lose weight when you take up running. Just how much, however, is up to you.
Daily Calorie Needs
When you’re trying to estimate your weight loss, it’s important to know how many calories you use in a day without running. By knowing what you burn without exercise, you can figure what it will take to tear through the 3,500 calories it takes to drop one pound of body weight. To calculate your daily caloric needs -- your basal metabolic rate (BMR) -- use the Harris Benedict Equation, which for women is 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years). Multiply that number by 1.1 or 1.2 if you are sedentary or lightly active throughout the day, or 1.3. or 1.4 if you are moderately or highly active. The resulting number will be the number of calories you need per day to maintain your current weight.
Once you know how many calories you use in a day, you can figure how much you’ll lose by logging your miles. The number of calories you burn per mile depends on your height and weight. The taller or heavier you are, the more energy your body needs to move. You can calculate the number of calories you burn per mile by multiplying your weight in pounds by 0.75.
To lose one pound of body weight, you need to create a calorie deficit of 3,500. Dividing 3,500 by the number of calories you burn per mile will tell you how many miles you need to run to drop a pound. How fast you’ll lose weight is then up to you and how many miles you log per week. For example, if you burn 100 calories per mile, you can estimate that you’ll lose one pound for every 35 miles you run. If you average 20 miles per week, you can expect to lose one pound in a week and a half, or two in three weeks.
Estimating how fast you’ll lose weight by running is just what it is -- an estimate. Outside factors such as diet, daily activity level and metabolism will affect how fast you drop the pounds while you run. If you increase or decrease your calorie intake, you will alter the rate at which you lose weight, and if you find yourself doing less daily activity after running, you will slow your daily calorie burn. The best way to drop pounds is by combining exercise with a healthy, calorie-appropriate diet. To ensure your best results, consult with your doctor before beginning your weight-loss efforts or running program.
After graduating from the University of Kansas with a bachelor's degree in sports information, Jill Lee served for 10 years as a magazine editor for the Fellowship of Christian Athletes (FCA). Also a published author, Lee now works as a professional writer and editor focusing on fitness, sports and careers.