Plank is one of my favorite...just kidding. Actually it's one of the hardest and most incorrectly done exercises. It actually started out in physical therapy called hoovering. Physical therapists love it because it makes the body work in one long kinetic chain. We're going to come down into like a push up position, but take a moment to make sure you've got your elbows underneath your shoulders, and I want you to try to leave your hands in line with your elbows and your shoulders and not bring them in because this is going to make you want to hold your breath, and one of the keys to plank is to take a big inhale before you even initiate the movement. Again, like you would in a push up, we're going to curl up on our toes, and we're going to think of bringing the navel into the spine. Breathe, inhale, exhale, keep breathing, and as long as you can hold this you want the body in one long line, extending energy through the top of the head. When you get too fatigue you're going to feel that tremor of truth, that shake start to happen, and the whole body, again, works as a unit, so you're going to really feel it all over. Keep breathing because the muscles shaking are crying for oxygen, so you've got to keep them fueled with the breath. Inhale, exhale, try not to let yourself swoop down with the hips or arch up, but just maintain one long line, holding to fatigue and breathing. Release down to the knees, and you always just let yourself take a moment to rest, head flex side to side, and then if you can come up. Start off by holding a good 10 seconds if you can. Obviously if you can't do it with quality over quantity, then work with what you've got and then progress from there.