Running on a treadmill is a great way to get your runs in on rainy days or during the cold of winter. And if you're looking to lose weight you're in luck, because the treadmill is an effective calorie burner. Burning more calories will generally result in weight loss, but you'll need to make sure your caloric intake is appropriate and that you have a healthy calorie deficit.
Calories Burned on a Treadmill
Several factors will affect the number of calories you burn on a treadmill. Running longer, faster and at a steeper gradient will burn more calories. Also, you will burn more calories if you weigh more. For example, if you are 150 lbs. and you run for 20 minutes at a speed of 6 mph on a level setting then you will burn 243 calories. If you were to increase the incline to 15 percent and your speed to 9 mph then you would burn 575 calories. A person weighing 200 pounds would burn 766 calories under these conditions.
Calorie Deficit
To lose weight, you need to create a calorie deficit -- that is, you need to burn off more calories than you eat. You will lose approximately 1 pound of fat for every extra 3,500 calories that you burn. For example, if you burn an extra 875 calories on the treadmill then you can expect to lose 1/4 pound of fat.
Diet
An important thing to remember about burning calories is that they will only result in weight loss if you maintain or reduce your caloric intake. If you simply eat back the calories that you burn off then you can't expect to lose weight. You should also be careful not to reduce your caloric intake below 1,200 calories a day. If you drop below this threshold your body can enter diet-induced adaptive thermogenesis, in which your metabolism slows down. When this happens your body burns calories more slowly, meaning that you'll need to spend more time on the treadmill to see equivalent weight loss.
Recommended Weight Loss
The Centers for Disease Control and Prevention recommends aiming to lose 1 to 2 pounds of fat per week. To fall within these recommendations you should aim to burn an extra 3,500 to 7,000 calories per week on the treadmill. Aim to spread your workouts through the week to avoid injury. For instance, if you are aiming to burn 3,500 calories per week you might aim for six treadmill workouts, each burning 583 calories.