3. Guard sit-up with jab, cross punches

TiffHallCore-cross-punches.jpg

This is the ab-solute best move for strengthening your core, while the cross body punches work the oblique muscles too. And you know what they say (well, what I say at least), tight obliques will cinch in that waist – like a belt.

» Start on your back with your feet together (heels touching), tucked up towards your butt and your knees pointing to the side – like a butterfly. 

» Keeping your guard up to your chin, perform a sit-up. As your shoulders pass over your hips, reach one arm across your body in a punch, then the other arm.

» Curl your spine back down to the floor, making sure you keep your belly button pulled into your spine.