PREPARATION
1.Lie on your left side. Rest your
  head on your left hand, and 
  place your right hand on the
  floor in front of you.
 
2.Place your right knee on the
  floor in front of you, at right
  angles to your body.

3.Straighten your left leg and 
  flex your foot.

EXERCISE
1.Breathe out as you raise your 
  left leg away from the floor.

2.Hold briefly, then breathe in 
  as you lower your leg back to
  the floor. 

The range of movement may be
small. Do not twist or jerk your 
leg to compensate.

MAINLY FOR: Adductors

To make this exercise more 
demanding, wear ankle weights.