3. Decline Push-Up
How to: Find a sturdy surface like a bench or a chair that you can place your feet on, or for an even bigger challenge, you can use an exercise ball. Starting on all fours, lift up into high-plank position and slowly raise your feet onto the bench, chair or ball, one at time. Once you’ve safely assumed the starting position lower yourself towards the floor—using the same motion as an ordinary push up and while concentrating on keeping your core tight and your spine neutral. Push yourself back up to the starting position and repeat for 8 to 12 reps.