Stretch your hip flexors to lengthen your stride and increase your efficiency.
Gin Miller

You can expect to log an average of 5,000 to 6,000 steps during a typical three-mile walk. That means your leg muscles are constantly contracting, especially the hip flexors, which are the cordlike muscles on the front of your hips and upper thighs that lift the leg for each step. Stretching them not only helps improve your hip flexibility and reduces soreness but can also help to lengthen your stride-meaning you can cover more ground efficiently and have a better workout. Although this stretch may appear simple, it's the best move to fully elongate the hip-flexor muscles. Add it to the end of your walk, or perform it after a short warm up. (Muscles are more pliable when they've been exercised, even lightly; stretching a "cold" muscle could lead to injury.)

Hip Flexor/Thigh Stretch

Perform this stretch from standing position holding onto a stationary object (tree or chair) for balance, if needed. Lift your right leg behind you, grasp the front of the foot, and pull your heel toward the buttocks. Make sure the knee of the bent leg is pointing down and is aligned with the knee of supporting leg. Tilt the hip forward to elongate the stretch in the front of the thigh. Hold for 20 to 30 seconds. Repeat on left leg.

Alternate position: Sit on a chair or the end of a bench with right leg and hip off the side edge. Drop the right knee toward the floor, grasp the front of the foot, and lift your heel toward your right buttock. Make sure the knee is pulled close to the chair and pointing down.

Tips on form

1. Do not force the foot to the buttock. This can put too much pressure on the knee ligaments.

2. Stretch in a smooth, controlled motion. Bouncing can cause muscles to contract against the stretch.

3. Take deep, slow breaths throughout the stretch.

4. Tighten the abdominals, and push the hip forward until you feel the stretch in the front of the hip and thigh.