Plank (and Variations)
How: To start, master a basic high plank: Start on all fours with your hands directly under your shoulders. Engage your core, draw your belly button in, and step each foot back into a high plank position. Hold for 30 seconds.
Once you can successfully hold a basic plank for one to two minutes (or several 30-second holds), start adding in variations to see gains.
Forearm Plank: From high plank position, drop down onto your forearms and hold.
X-Plank: From high plank position, lift right hand and left leg up. Stabilize through your core to keep hips square. Return to high plank then repeat on the other side. Continue to alternate for 30 seconds.