Walking or running can help you lose weight as fast as almost any activity, but the key to weight loss is how many calories you're burning when you exercise. Calorie burning relates to the intensity of the activity and the duration.
If you're going to cover 4 miles a day, you will lose weight immediately, simply by burning hundreds of calories with each run. That's assuming, of course, you don't start eating more and more every day. The speed at which you lose weight, however, will depend on how many of those miles are run or walked.
You can walk or run 4 miles a day to lose weight, but the key to maximum gains is the intensity with which you exercise.
Do the Math
Losing weight is all about burning more calories than you consume, and 3,500 calories equates to about one pound, says Mayo Clinic. So if you walk or run off 500 calories every day for a week, you'll lose around one pound per week. For example, a 185-pound person running 4 miles a day would burn close to 600 calories during that run according to Harvard Health Publishing.
That's assuming he's running at 6 mph for about 40 minutes. Walking at 3.5 mph for about 80 minutes would also cover about 4 miles and would burn around 535 calories. Even though walking is less intense, if you cover the same amount of ground, you'll ultimately lose around the same amount of weight by walking. It will just take longer each day.
10,000 Steps or 4 Miles
In the 1990s, when people stared to use pedometers to track their steps, the idea of walking 10,000 steps a day was used in the marketing of the devices. ACE Fitness suggests a number of ways to get in your 10,000 steps, but walking and running are no brainers. The figure amounts to between 4 and 5 miles, depending on the length of your stride.
While there is nothing particularly special about that distance — other than that it's a nice, round number — a person who is walking briskly can walk about 4 mph. That means you can get your 10,000 steps, or 4 miles, done in about an hour.
Crank up the Speed
There is some dispute whether the longer time spent walking a certain distance, as compared to the time spent running the same distance, actually burns more calories because you're actively engaged longer. However, it takes about twice as long to walk a specified distance as it does to run that same route. So if you're looking to save time with your workout, crank up the speed from a walk to a run to maximize your efforts.
Walking and Running
Running 4 miles a day will help you lose weight in a hurry. But don't discount walking 4 miles a day, especially if you are recovering from a joint injury, accident or another physical ailment that might lead to restricted physical performance, says Harvard Health Publishing.
While running 4 miles a day may seem like a great idea at first, check with your doctor about any limitations you should consider. And you can always start out walking before moving on to running to help burn more calories in a given time period.