Three speed-boosting interval routines

Got a need for speed, a la soccer star Ali Riley? Pick one of these routines designed by exercise physiologist and espnW contributor Amy Dixon, the group fitness manager for Equinox in Santa Monica, Calif. Now, lace up those kicks and get ready to go -- fast!

Interval Workout No. 1: Tabata Intervals

Tabata routines are a style of interval developed at the National Institute of Fitness and Sports in Tokyo. The principle is that you're "working" for twice as long as you're resting. Here's how it goes:

Hop on the treadmill and run on a 1 percent incline for 20 seconds at an all-out, run-for-your-life pace, then recover for 10 seconds (hop onto the treadmill rails, carefully). Repeat this cycle eight times, for a total of 4 minutes of action.

Rest for as long as needed and repeat up to eight times, depending on your fitness level.

Interval Workout No. 2: Endurance Intervals

The goal is to work as hard as you can without becoming breathless. Choose whatever style of cardio (swimming, running, cycling, etc.) you enjoy most.

Minutes 1 to 6: Warm up at easy-to-moderate intensity (you are able to speak in full sentences, no prob).

Minutes 6 to 11: Work as close to breathless as you can for 5 straight minutes (you can speak only in spurts of three or four words).

Minutes 11 and 12: Ease up to a moderate intensity (you can chat, but would rather not!).

Minutes 13 to 18: Work as close to breathless as you can for 5 straight minutes.

Minutes 18 and 19: Ease up to a moderate intensity.

Minutes 20 to 25: Crank it up and work as close to breathless as possible.

Minutes 25 and 26: Ease up to a moderate intensity.

Minutes 27 to 32: Pick up the pace and push yourself to as close to breathless as possible.

Minutes 32 and 33: Ease up to a moderate intensity.

Minutes 34 to 39: Pick up the pace and push yourself to as close to breathless as possible.

Minutes 39 and 40: Ease up to a moderate intensity.

Minutes 41 to 46: Work as close to breathless as you can for 5 straight minutes.

Minutes 47 and 48: Ease up to a moderate intensity.

Minutes 49 to 54: Pick up the pace and push yourself to as close to breathless as possible.

Minutes 54 to 60: Cool down at an easy intensity.

Interval Workout No. 3: Power Intervals

1. Box Jumps: Stand facing a 12-to-18-inch-high box or step. Squat slightly, then swing your arms for momentum as you jump up onto the box, landing with your knees soft. Step down and continue for 1 minute at a fast pace. Recover for 30 seconds. That's one rep -- do four.

2. Side Shuffles: Place two cones about 6 feet apart. Side-shuffle between them, traveling back and forth as quickly as possible for 1 minute. Rest for 30 seconds. That's one rep -- do four.

3. Lateral Bounding: Stagger 10 cones so they form a zigzag line with about 6 feet between them. Start at the first cone and bound to the right to arrive at Cone 2. Next, bound to the left to arrive at Cone 3. Continue bounding back and forth until you reach the end of the line. Sprint back to the beginning and run through it again. Continue for 1 minute, and then rest for 30 seconds. That's one rep -- do four.

4. Traveling High Skips: Find an open area and skip, using your momentum to get big air and moving forward as quickly as possible. Continue for 1 minute, then rest for 30 seconds. That's one rep -- do four.

5. Switch Lunges: Perform a lunge with your left foot forward. Jump up, switch your legs in the air and land in a lunge with your right foot forward. Continue for 1 minute, moving as quickly as possible (while maintaining control). Rest for 30 seconds. That's one rep -- do four.

6. Fast Feet: Stand with your feet together and run in place as quickly as possible for 1 minute, dropping to the floor (think: bottom of a push-up position) every 10 seconds. Recover for 30 seconds. That's one rep -- do four.