Here’s a great stretch for the core as well as a back strengthener!
It’s called the cobra pose in yoga. This is one of my favorite stretches, and I always make sure to do it after I do a challenging core workout.
Lie on your stomach with the tops of your feet pressing into the ground, with your arms bent and hands pressing the ground under your shoulders. Inhale and straighten your arms to lift your chest and head off the floor. Hold for a few breaths and then slowly lower back to the ground. You can push back into a nice child’s pose from here as well!