Low Lunge
How to do it
From kneeling, step one foot forward outside your hands and lower the back knee to the floor, with a folded towel under it. Walk the front foot forward until the shin is vertical or angled slightly past it. Bring both hands to the inside of the front foot, then let the hips sink down and forward. If the floor is within reach, come down onto the forearms; if it is not, stack a couple of books or use the seat of a chair under your hands. Then stop working. Let the weight of your own body take you down over the minutes, and change sides.
Why it's good for runners
An hour of running is an hour of hip flexion that never fully extends. The tissue at the front of the hip — the psoas and the muscles either side of it — shortens because nothing in the day ever asks it to be long, and a short front hip is what stops the stride opening up behind you. The low lunge is the deepest place in this method that tissue is taken, and it is the only one that takes it for minutes rather than breaths.
That length is where the real change happens. A shape held for twenty-five seconds lengthens muscle, which springs back. A shape held for three minutes starts reaching the connective tissue underneath, which is what actually holds a range once you have it.
Common mistakes
Don't hold yourself up. Hovering above the shape on straight arms with the hips high is the most common version of this pose and it does almost nothing — the point is to hand your weight over to the floor and let time do the rest. Don't chase the forearms; propped hands and a settled body beat forearms on the floor and a body that is fighting. Don't let the back knee take the pressure bare on a hard floor. And don't bail the moment it gets uncomfortable — deep and dull is the pose working, but anything sharp, especially in the front knee, means back off now.