Kenna and Moe, co-owners of Sweat Pilates in Culver City, share this core-strengthening, do-anywhere move:

• Assume a standard pushup position, hands in line with shoulders.
• Lift your right foot, pointing the toe behind you and squeezing the glutes as you keep your lower body engaged. Hold for a count of 5. 
• Cross your right leg under your body and reach to touch your foot with your left hand. (You will be balancing on your left leg and right arm.)
• Lift the left foot and hold for 5 counts.
• Cross the left leg under your body to touch the right hand. Repeat 5 times on each side.

As your core gets stronger, your coordination will improve. Experiment with timing and reps to keep your body on its toes!