How to Burn 800 Calories a Day on a Treadmill

Burning 800 calories a day can help you fast-track your weight-loss goals. Although this type of calorie burn is possible on a treadmill, you're really going to have to work for it, using extra speed, incline or a serious time investment to meet that ambitious goal.

If burning 800 calories a day on the treadmill is your goal, it's going to take a while. The American Council on Exercise physical activity calorie counter estimates that if you weigh 185 pounds, you'll burn 167 calories in an hour of easy walking at 2 mph. It'd take you almost five hours to burn 800 calories at that pace.

But if you walk faster, you'll burn more calories. At a brisk 3.5 mph walk the same person would burn about 318 calories per hour, which works out to just over 2.5 hours of walking to burn those 800 calories.

If you'd like to get your calorie burn out of the way in a more realistic time frame, try a run. For the sake of comparison, ACE estimates at the same 185-pound person would have to run on a treadmill at about 6 mph to burn 800 calories in an hour. You can also add an incline or weighted vest to your treadmill walking — but there's a dearth of research to quantify exactly how much of a difference this makes.

One of the most notable works that gets down to specifics is a December 2013 master's thesis by James Jeremy McCormick, published by the University of New Mexico. Although McCormick's study only involved 13 people, he calculated their mean (average) calorie burn when walking on a horizontal treadmill or three different incline levels.

The exercisers averaged 3.4 calories/minute at no incline, 4.6 calories/minute at 5 percent incline, 6.4 calories calories/minute at 10 percent incline and 8.2 calories per minute at 15 percent incline. With a little simple math, that extrapolates to the following increases in calorie burn when compared to level walking:

• 5 percent incline: 35 percent increase from level walking
• 10 percent incline: 88 percent increase from level walking
• 15 percent incline: 141 percent increase from level walking

McCormick also calculated mean calorie burns according to the extra load applied by a weighted vest. On a level treadmill, adding 10 percent of the exerciser's body weight resulted in a modest increase of just under 3 percent more calorie burn. That number went up a bit with additional incline, generally ranging from 8.5 to 9.2 percent increase in calorie burn.

Read more: Not Sure What to Do on the Treadmill? Start With These Workouts

Although you can burn 1,000 calories on a treadmill or even more if you're really serious about it, that doesn't mean this is always the right type of exercise. In particular, frequent running creates a lot of impact. Cross-training with other activities gives both body and mind a break and is a good way to reduce your risk of overuse injuries.

Harvard Health Publishing offers a helpful chart of calorie burn estimates, including a number of non-treadmill activities that offer similar levels of calorie burn to a 6 mph run on the treadmill. A few of these are:

• Stationary cycling
• Swimming
• High-impact step aerobics
• Jumping rope
• Martial arts

It's also worth a few minutes of your time to consider whether your weight loss goals are both realistic and healthy. In general, to lose a pound of body fat you must burn 3,500 more calories than you take in. But faster isn't always better: The Centers for Disease Control and Prevention recommend just 1 to 2 pounds per week as a healthy, sustainable rate of weight loss.

That works out to a daily calorie deficit of 500 to 1,000 calories. You can achieve that by slightly decreasing the amount of calories you take in, increasing your physical activity — with burning 800 calories a day on the treadmill as an excellent example — or both. But don't restrict your calorie intake to the point of starvation and don't overload yourself with more exercise than your body is ready for: Increase the intensity gradually so it has time to adapt.

The National Heart, Lung, and Blood Institute notes that most people can lose weight safely on a plan of 1,200 to 1,500 calories/day for women or 1,500 to 1,800 calories/day for men. But very low-calorie diets, which they quantify as 800 calories/day or fewer, should only be undertaken with a doctor's close supervision.

Read more: Lose Weight, Tone Up and Get Fit With Treadmill Walking Workouts