How to do a Plank spider

From plank position, do alternating knee and hip flexion trying to touch your elbow with your knee

Count one repetition each time you flex your knee.

Note:

– Keep the horizontal posture.
– Try not to move or rotate the hip when you do the knee flexion.
– If you cannot touch the elbow yet don´t worry, you will gain flexibility as you train.

Alternative exercise:

– Sit up with extension.