Put something heavy on a towel and wrap it up.
2. Stand Straight with your hands and feet Shoulder-width apart and hold the towel with a neutral grip.
3. Stick your chest out, Unshrug your shoulders and contract your lats and abs.
4. Curl the towel Up towards your chest and squeeze your biceps (Keep the distance between your palms).
5. Hold the contraction for a moment and slowly come back down.
Working muscle/muscles:
