This exercise is great for working the hip flexors while using the abdominals to stabilize.

1. Start this exercise by lying flat on your back on a mat. Fold arms at sides so that your hands are resting face down underneath your lower back. Lift legs about 3-4 inches off the mat, keeping them straight.

   

2. Inhale and lift one leg up and the other leg down about 2-3 inches each way. Keep switching legs up and down as if you were slowly doing a swim kick.

   

3. Do 10-12 reps, and return to starting position. 1 rep would be both legs alternating kicks once. Increase reps as you progress with this exercise.

   

4. Recommended reps: 10-12, and increase as you progress.