How to do it: Lie facedown on the floor with your arms bent at the elbow and placed beneath your head. Lift your upper body as far as you can. Stay in this position for a second, and slowly return to the initial position.
Results: Tones and strengthens the spinal muscles.
Do the following sets for 6 days:
Photographer Roman Zakharchenko, model Nadezhda Makarova, illustrated by Daniil Shubin for BrightSide.me