Today we're going to do a High-Intensity Interval Training workout, or HIIT, H-I-I-T. What we'll do is 20 seconds of an exercise, pushing as hard as you can, then taking 10 seconds' rest.

This 30-minute workout delivers on both fronts ... distance and time so that you’re stopping at approximately every 400m interval and giving yourself ample time to recover.

The interval workouts above build speed, but this workout below will improve your stamina to run faster and more efficiently. The key is to run at the right effort (your “red line”) so you can ...

One of the best ways to do that is with a style of workout called interval training. Most runners focus on racking up mileage when they start running. Taking that approach to build your aerobic ...