Pace Setter

• One of the biggest and most obvious differences between fast walking and running is the pace. They can both be done at high intensities, but fast walking is done at slower speeds. It is not uncommon for fast walking paces to go as high as 5 or even 6 mph. Running, on the other hand, depending on the individual, usually starts at about 5 to 6 mph and gets faster after that.
  
  

Half Enough

• Walking undoubtedly cause a caloric expenditure, but of course much less than running. For example, a 160-lb. man would burn approximately 835 calories in 60 minutes of running at 7 mph. That same man would burn 472 calories per hour even at a race walking pace. At a 4-mph pace, the caloric expenditure would be 363 calories (see Resources below).
  
  

Joint Session

• Another major difference between fast walking and running is the toll they take on the joints. In running, the body is literally coming off the ground one foot at a time and then landing forcefully with each stride, so the joints of the ankles, knees and hips take a lot more of a pounding. The impact is a lot less severe with fast walking, being that there is always one foot coming in contact with the ground before the other one is lifted.
  
  

Conflict of Energy

• The insides of the body are also affected differently. For example, it is not that hard to eat a large meal and go for a fast walk. But this is not the case with running. Running takes more energy, oxygen and blood flow than fast walking. When the body is running, this blood flow and oxygen is being taken away from the stomach, where it is also needed to digest food. The body then has a conflict, which may result in stomach cramps, labored breathing and muscle soreness. This gets magnified by the fact that the body is bouncing up and down and the food in the stomach sloshes around.
  
  

Breath Control

• Fast walking takes less oxygen consumption than running. The amount of oxygen consumed during exercise is called VO2 max, or Volume of Oxygen Consumed. Higher VO2 maxes usually indicate higher aerobic capacities and are often used to determine the performance levels of endurance athletes.