- Lie on your back and open your legs into a diamond shape (aka butterfly legs), with the soles of your feet pressed together and knees out wide. Extend the arms overhead.
- Inhale to curl the torso up, and tap the floor in front of your feet to stretch your glutes a bit.
- Slowly lower back to the starting position.
- This counts as one rep.
Technically considered a sit-up, this effective move works the abs through a larger range of motion and adds some functional fitness training to the challenge.