Thinking about food?

Do you think about eating? 
I think about food and eating from the moment I wake up. Most times at one meal I’m preparing for the next meal. Or at the very least figuring out what I’m going to be doing for that meal.
Does that sound familiar? I know I’m not the only one obsessed with food.  
A student (obsessed with eating, like me) asked last week:
Why don’t we eat before a yoga class, or drink water during class?
Water puts out the fire, the prana. I said with a head bobble. 
I’m sure you’ve heard this answer before. I’ve given this answer before. That’s what I’ve been told. 
But they weren't satisfied. I wasn’t either. I don’t talk in prana, or chakras, or Bhav.  (I’m not even sure I spelt bhav correctly) 
They wanted more. They wanted the WHY. They wanted the heart. So I started to go into it.
I’m a nurse. Part of what we do is patient education. Taking the big complex science and making it digestible and understandable. A translator, if you will.
I looked around online for some direction to point them towards. listed food to eat before yoga, was basically the same article. Acefitness, huffingtonpost, shape, menshealth, etc listed the worst things to eat before working out, foods to avoid, ‘diet rules backed by science.’ 

None of it explained **WHY**.
Have you ever gotten a cramp during a run? 
Muscles used for peristalsis (the movement of food along the intestinal tract) are locking down trapping food that produces gas. 
When running your heart can’t keep the necessary blood volume up to digest food AND give blood to the muscles engaging in a fight-or-flight response. 
The primitive part of the brain takes over and shuts down the entire GI system. The brain thinks it’s being chased by an animal and going to die.

Navasana is a beast! It want’s to eat you.

All secondary functions are halted so that you can get away.
She began to understand.

That was the simple explanation, beyond the simple, 'it puts out the prana.' You want more?
What follows is **Digestion 101** A&P of the digestive system in about 3 minutes without the complicated parts and exams.

Once we swallow - digestions becomes involuntary. The Autonomic Nervous System (ANS) controls this for us automatically. 

Think, Autonomic is Automatic.
This means we don’t have to think about which hormones and enzymes need to be released, or about peristalsis (muscle movement of food) in the gastrointestinal tract. Leaving us more time to focus our attention on more important matters like double tapping a photo on Instagram, or a recipe on  Pinterest. 

Digestion happens when the body is at rest, and not running from the belly of a beast. Or wishing the count was a little faster in Navasana.
The ANS works on the unconscious control of organs. ie. Digestion, Heart rate, respiratory rate, pupil dilation, urination and sexual arousal. 

Yes, sexual arousal is automatic. But this is about digestion. Stay with me here.
Because we are unconsciously operating these systems the body has divided them into two groups. Those that need immediate attention, such as in a ‘fight-or-flight’ scenario, like being chased by a Navasana or a Marichyasana D are divided into the Sympathetic system.

The other system, the parasympathetic system, is for those that don’t require an immediate response and are in use while we are resting. Like Digestion.

The body likes to stay in balance. The two systems, sympathetic and parasympathetic, function in opposition to each other.
Homeostasis. (That big word from High School Biology) 
The heart likes to have blood. In order to do so it needs to maintain a certain pressure during activities. It relays a message back to the brain constantly letting it know where to direct the blood. 

During activity such as running, yoga, surfing, biking, etc. Our fight-or-flight system takes over control. The body demands more blood for the muscles and lungs (sometimes as much as 1.200%) This diverts blood away from the gastrointestinal tract and skin. Our heart rate increases and peristalsis decreases. 

Remember that Fabulous Raw Mexican lasagna you had before coming to class?
The stomach has two ring like muscles that seal in food for hours, mixing it with acids to target bacteria as well as enzymes to process fats and proteins. It typically takes about 1-2 hours before the stomach empties all of it's contents into the intestine for further incorporation into the body. But it only does this when the body is at rest.

That’s why it is recommended to NOT eat 1-2 hours before a yoga class or engaging in physical activity.

In that yoga class, there are no extra enzymes getting to that food. No extra breakdown. In fact the brain is getting mixed messages. During digestion. The vagus nerve is trying to impart control over the parasympathetic system asking for more blood to the GI tract because of the metabolic demand of the gut.

But you are in a yoga class twisting you body, standing on one leg, bending over backwards, trying to get you leg behind you head. Running from the beast. 
Essentially your body is freaking out.
Practice is hard enough. Why making it more difficult you?

Ashtanga Nurse RX:

Drink a cup of coffee (hot water and lemon is a substitute) 1° before practice in the AM*

If taking practice in the afternoon eat NOTHING 1-2° before taking practice. 
Allow 30’ after practice before consuming food.**
Talk with your teacher about dealing with low blood sugar or if feeling faint. Possibly, try eating a banana as they are easily digestible. 

*NO COFFEE NO PRANA (Coffee stimulates peristalsis and aides with deification, elimination of waste.) 
** Give the body time to stabilize the blood volume and recover from the fight-or-flight response.