I just spent the weekend on my latest Yoga Therapy module and while I learnt SO much fascinating information, as always, one thing really hit me that left me saying,
‘Wow, my students need to hear this!’
Ever had that moment in an intense stretch when that oh so sweet release comes in and you're left sighing out ‘Ahhhhhhhh.’
We learnt about this amazing phenomenon called the ‘reverse stretch flex’.
When we remain in the same position for a length of time (think Yin), motor neurons send messages to the muscle to contract in order to prevent the muscle from overstretching. So the centre of the muscle (the ‘belly’) will start to contract and this then starts to pull at the tendon - ouch!?
So why are we doing Yin and pulling at tendons!?
Wait a minute…
This tension then activates a sensory body on the tendon, known as the ‘golgi tendon body’. The golgi tendon body thinks, wait a moment, do I really want to contract so much I come off the tendon!? - double ouch!!
So the golgi tendon body decides to save the day and sends action potentials (messages) to the motor neuron. When the action potentials reach a certain threshold (the one saying ‘no more, help me please!’), the reverse reflex is activated and muscle contraction is inhibited.
‘Ahhhhhhh, sweet release.’
But wait, there’s just a little bit more and THIS is the good stuff!
Holding a pose for an elongated length of time (say 3-5 minutes in Yin), also provides an opportunity to watch how the mind responds to our relationship with the stretch. It is the perfect time to develop mindfulness, but it’s also the perfect opportunity for the mind to start ruminating.
There is research that suggests some extremely interesting findings around long holds. Researchers found that entering the pose there was actually an initial increase in blood pressure & heart rate.
At the beginning of the stretch/pose the stretcher wants to fidget, demonstrating levels of physical discomfort or mental rumination - we’ve all been there, right?
Then in the 2nd-3rd minute of the hold, blood pressure and heart rate would start to decrease (as that reverse reflex kicked in) and along with that, the desire to come out of the pose and negative thinking would reduce too.
After FIVE minutes, blood pressure & heart rate decreased to a point lower than baseline, correlating with a sense of improved well-being.
All of a sudden do you really want to do more Yin!? Yeah, me too.
And, I’ll be increasing my holds to a minimum of five minutes next time too!