5 Ab Exercises for a Faster Run

Ball CrunchBall CrunchBy the editors for FITNESS Magazine

Get a whittle faster. In a study, runners who did these moves four times weekly shaved a minute off their 5K times in six weeks. Try two sets of 12 reps each.

Related: The FITNESS Guide to Running

Ball Crunch

Lie faceup on a stability ball, knees bent 90 degrees, feet on floor. Put hands behind head with elbows out to sides and crunch up, then lower.

Source: Study at Barry University in Miami Shores, Florida

Related: Cameron Diaz's Abs Workout

Hip RaiseHip RaiseHip Raise

Lie faceup on floor with heels on ball, legs extended, arms by sides. Lift hips, forming a diagonal line from heels to shoulders. Hold for 1 count; lower.

Related: Firm Your Hips, Thighs, and Butt

Back ExtensionBack ExtensionBack Extension

Lie facedown on ball, knees bent and feet on wall behind you, toes on floor. Bend elbows by sides, bringing fists in front of shoulders. Lift upper body; lower.

Related: The Best Winter Running Gear to Stay Warm

Arm/Leg ReachArm/Leg ReachArm/Leg Reach

Start on all fours. Slowly extend left arm and right leg at the same time until both are parallel to floor; hold for 1 second. Return to start. Switch sides and repeat to complete 1 rep.

Related: Top 10 Arm Moves for Better Biceps

Russian TwistRussian TwistRussian Twist

Lie faceup on ball, knees bent, feet on floor. Extend arms toward ceiling and clasp hands. Keeping hips still, rotate upper body to right, then left, to complete 1 rep.

Related: Sneak Preview: Best Running Shoes for 2011

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