4 Steps to a Stronger Back
Opposite arm & leg lift
Get down on all fours with hands under shoulders and knees under hips. Reach your right arm forward; at the same time, stretch your left leg back.
Hold for 5 seconds, then release and repeat using the left arm and right leg; that's one rep. Do 10 to 15 reps.
Watch the video: Opposite Arm and Leg Lift