Quit saying, "my aching back" and start doing this effective move to strengthen your back. This exercise will help you get stronger and avoid injury, as well as improve your posture.
How to do it: Start on all fours. Reach your right arm forward while simultaneously stretching your left leg back and flexing your foot. Hold for 5 seconds, then release both your arm and opposite leg. Repeat using the left arm and right leg. That's one rep. Do 10 to 15 reps.
Trainer tip: Make sure to keep your back, arms, and legs straight.
Try this move: Opposite arm and leg reach