Mountain Climbers

Setup
Lie prone on mat. Place hands on mat under shoulders and legs together with forefeet on floor. Raise body upward by straightening arms keeping body in straight line (between ankles, knees, hips and shoulders). Arms should be fully extended with hands directly under shoulders.
Movement Instructions
Raise leg and bring knee up and in to chest, then return. Switch legs and continue to alternate repeating the exercise.
Comments
Try to keep hips down and in line with shoulders and knees and not raise up as you do the exercise.