08 July, 2011
How Much Weight Can I Lose If I Run 4 Miles 5 Days a Week?
With a consistent training program, running can be an effective method to lose weight. When you watch world-class distance runners, you will notice that all are thin. Low body fat of elite sprinters allows their muscle definition to be seen. While you may not aspire to be a competitive athlete, you can lose weight by running. Several factors will determine how much weight you lose.
To lose weight, more calories must be expended than consumed. How many calories you need to maintain your weight depends on your muscle mass and activity. Increasing your activity will burn more calories. A pound is equivalent to 3,500 calories. For instance, if you run 4 miles five times a week, expending 350 calories each time, you will lose 1/2 lb. per week, resulting in the loss of 1,750 calories in a week.
When you start a regular exercise program, you may also change your diet. If you are eating 1,800 calories daily and also burning 2,300 calories each day, you are using 500 calories more than you are eating each day. In seven days, you will have expended 3,500 more calories than you consumed, which means you will lose a pound a week. This only works as long as you are eating a balanced diet. If you are eating too few calories, your body goes into starvation mode, slowing down metabolism so fewer calories are used.
When you are walking, one foot is always on the ground. Running involves lifting the body off the ground with every step. The amount of work in running increases with body weight. Using the calculator on the Fitness website, running 4 miles in 40 minutes burns 306 calories if you weigh 100 lbs., while a 200-lb. runner burns 612, which is twice the calories.
Just like a car uses more gas to go at higher speeds, so do humans. Running 4 miles in an hour is 4 mph. Runners omit the term “per mile” and refer this as a 15-minute pace, which is written as 15:00. A 4-mile time of 30 minutes is a 7:30 pace or 8 mph. Fast runners at a 5:00 pace are going to finish 4 miles in 20 minutes.
The calculator at FitnessMagazine shows there is a 138-calorie difference between a 150-lb. runner doing 20 minutes at a fast 6:00 pace, which amounts to 367 calories, compared with the same person running for 20 minutes at 10:00 pace using 229 calories.
Running faster means that one exercises for less time. When effort and time are combined, there is not much difference in calories consumed by running 4 miles. There is only an 18-calorie difference between finishing the mile in 40 minutes or 24 minutes. A 150-lb. runner covering 4 miles in 40 minutes, a 10:00 pace, uses 459 calories. The same runner would expend 441 calories to finish in 24 minutes at a 6:00 pace.
Mountain trail running in Colorado or other high elevation requires more calories than running on a track at sea level for several reasons. Running on an uneven surface, slippery surface or on sand requires more effort and uses more calories. Moving your weight against gravity by running uphill or up sets of stairs burns more calories than running on a flat surface. Training at high altitude where there is less oxygen also raises the number of calories used.
Running Fitness and Form
As you get fit, you will notice that it takes less effort to do the same run at the same time. Your stride may become smoother. You are using fewer calories to run. Aerobic fitness can be measured by variables such as VO2 and lactate threshold that show how your body metabolism uses oxygen during exercise. Gina Kolata in The New York Times explains that there is not a specific running form that is most efficient. An estimate of calories used during a run can be made from pace, terrain and your weight. Even a top running coach observing how you run cannot tell exactly how many calories that you burn. Calculating calories used in a run is not an exact science.
- female runner image by jimcox40 from Fotolia.com