So, you’re bouncing through a high speed sun salutation with a breath count of 1 second and get 10 rounds and a few quick warrior 2’s punched out in 5mins. Morning yoga done! Then you head off to work feeling flushed and end up stiff as a board 30 mins after you sit down because your muscles have all shortened.
Yoga’s supposed to make you flexible right? Let me introduce the myotatic stretch reflex. It’s a lightning fast muscle response circuit that enables you to run and jump, and then makes it really hard to touch your toes afterwards.
At its most basic, the human body consists of a skeleton, with a bunch of muscles attached to it that enable joints to move. As we live on Earth and not, say, on a space station, gravity presents a force that we simply evolved to deal with. The fact that gravity is there means that bouncy agile animals like humans have developed neat response mechanisms to enable moving quickly.
Take running. As you run, the front leg hits the ground and sends a big spike of force into the leg. If you had to consciously control the big quadriceps muscles each time you landed, you’d probably never get anywhere as you’d just fall down. The exacting muscle response to a single legged jump with enough rebound to keep momentum and balance is pretty much automatic. The conscious brain isn’t that fast to respond to outside events, there are all these little automatic response nerves that take care of stuff like running or jumping – or any quick powerful movement. If you jumped and those automatic response nerves – the myotatic stretch reflex receptors – didn’t fire, you’d simple pancake hard. Gravity is not your friend in this action.
So, those little receptors – think of them as poking sticks – are scattered all over the body, with most of them in places that will take notice of big gravity punches – like the knees, elbows, hips. You step, and the one in the knee pokes the lower motor neuron in your spinal column, which immediately flexes the quadriceps while completely ignoring to tell the brain anything happened. You’ll notice it eventually, because you’ll feel the shoe change around your foot, and your shorts will get real tight around your suddenly bulging upper leg. But you aren’t in control the big quad flex that kept you off the floor.
The next fun fact about this stretch reflex (which is named backwards I think) is this. When it pokes a muscle into forceful reaction, the muscle gets tighter. That’s why when you run you end up so stiff. You’ve send 1000’s of continuous pokes through this superfast response loop to keep taking landing shock which also makes them stiffen up. So the stretch reflex makes your muscles stiff and inflexible.
This is the important aspect for yoga. Fast movements equal unconscious movement. Those nerve receptors are doing the work of controlling big muscle groups. Your conscious control is floating around doing hardly anything. Mindful muscle engagement means you have to move slowly to avoid triggering the automatic responses.
Rushing down and back up in a plank to chatarunga transition (pushup) is not the same as a slow controlled exhale and lower with straight back, keeping the spine from sinking under the shoulder blades with elbows hard in the ribs, pausing, then inhaling back up.
Try it. Do 2x20 quick blasting pushups, have a 5-10min break, then do 1 pushup that takes 10 seconds to decend, 5 seconds pause, then 10 seconds to rise. Exhale on the way down, inhale on the way up. Keeping the chest cavity moving is another way to keep these reflexes calm.
Slow muscle moves take significantly more effort to control. There isn’t any valid shortcuts, because any speed will poke automatic responses, taking the mindfulness out of the practice. If you want to build strength, you’ll get far superior results if you slow down poses, and especially transitions – that’s why a slow float is so damn hard compared to a jump. You’ll build clearer body awareness, which will increase your ability to engage different muscles in every situation. And you wont end up stiff and sore because you over poked the myotatic receptors.
Lastly – if you a lot of the GR stretch/beginner classes, you’ll be aware of how staggeringly strong all of those slow poses can be.
Scientific Keys, Ray Long, MD
Anatomy of Hatha Yoga, H. David Coulter, PhD.