Plank
Start on your hands and knees, hands under your shoulders, knees under hips.
Brace your core and bring your knees up until your legs and hips are in a straight line. Weight supported on the balls of your feet.
Maintain a straight line from your heels to the top of your head, but keep the neutral, natural curve of your spine, not a flat back.
Keep your hands or your elbows right below your shoulders, depending on preference and need.
Make sure you don’t let your hips drift too high or dip too low.
If you struggle to hold a plank for more than 10 seconds, try the elevated plank.