How to measure brisk walking

Exercise experts recommend "brisk walking" as an excellent workout. But just how fast is brisk? Generally 3 to 4 miles per hour. But since humans don't come equipped with a built-in speedometer, you need an easier way to measure your walking speed. One way is to count your steps per minute. As long as you are walking on level ground, here's a guide to walking pace: slow, 80 steps a minute; moderate to brisk,…