To do the Inchworm, start standing with your feet together. Bend over and place your hands on the ground in front of you while trying to keep your legs straight. Walk your hands out while keeping your legs straight until you are in the plank position. Then drop your hips toward the ground and arch back, pressing your chest out. You can even look back and up toward the ceiling as you drop your hips and press your chest out. Keep your arms straight as you do this almost Upward Facing Dog variation.
Then return to the plank position before you begin to walk your feet in, keeping your legs straight and pushing your butt up toward the ceiling. Walk your feet in as close to your hands as your flexibility allows. Stand up.
Repeat walking your hands back out while keeping your legs straight. Beginners may need to bend their knees a little as they perform the Inchworms. Try to stretch your hamstrings though as you walk out and back in.