Step 1: Begin in the top of a pushup position with your hands directly underneath your shoulders.
Step 2: Lower yourself down keeping your elbows close to your sides to work the triceps and chest.
Step 3: As you return rotate your body completely to one side, stack your feet into a side plank. Hold for a count of two before returning center. Push up again and rotate to the opposite side. Repeat 20 times (10 on each side).
Modifications: a) Perform pushup with knees on floor.
b) When you rotate to side plank cross your top leg behind the front leg.
Challenges: a) As you push up slowly count to four.
b) In side plank lift the top leg up.
Benefit: To perform a successful pushup and side plank (let alone 20), your entire body has to stay tight so you actually end up working every muscle in your body. Additionally, by keeping the elbows in tight you work the triceps more than a regular pushup, while finally getting rid of those turkey arms.