Fuel Supply to Muscles in Normal, Stress and Starvation Modes
The middle seat. The people in the aisle seats try to avoid eye contact with you in the hopes that the vacant middle seat will not get filled. I chose a middle seat near the front of the plane. PHX:DTW will take 5 hours. I crawled over a large, elderly lady and sat next to who I thought was her grandson. Turns out he was an unaccompanied minor, and the aisle person was an unaccompanied major with bad knees. When she initiated a political attack on the current president, I decided to pay attention to the 6 year old child in the window seat to pay it forward to the times I sent my own son to travel by himself. In fairness, one international flight that my son boarded when he was 6, AMS:DTW, was spent with a new buddy in first class with pizza and ice cream, so it wasn’t really a hardship that needed to be repaid.
Jamal, unfortunately, wasn’t so lucky. First off, he was starving, and his father hadn’t packed any snacks for him. He is allergic to nuts which was all that I had, and the grandmother with a carryon full of food that could supply a large Super Bowl party – would not share. Jamal got airline mini pretzel bags and pop (soda for non Michigan people). He kept busy for a bit with a variety of activities that he pulled out of his backpack, then he put everything away and wanted to chat. ‘Don’t you wish you had brought some toys?’ There wasn’t enough room to open my laptop, so yes, smaller toys would have been better.
To say that Jamal was wired was an understatement. Drink soda, crawl over the adults to pee. Color, stop coloring. Beg the flight staff for more pretzels. Then the hiccups started. I began to understand why the universe put me in that seat. Jamal had been hit by lightning. He lost a younger brother somehow, but a 6 year old could not even begin to process or discuss the trauma of those circumstances. The hiccups were aggressive. I found the nerve calming salve that I discovered in Mexico and started to massage his neck at cervical C3, the exit of the phrenic nerve which supports the diaphragm, which is the muscle indicated in hiccups. The hiccups stopped. I realized that working on a young child without the parent’s permission was a bad idea, but there was a very short window of opportunity to help. The remainder of the flight was spent trying to relax the spine of this very bright child so that he won’t be tagged a hyperactive nuisance. I commented to his mother after deplaning that he might smell funny from the salve. She was very gracious and thanked me for looking after him.
The electrical current in Jamal’s body had been rewired from the lightning strike, and the neurological communication related to providing energy to muscles was altered – hopefully not forever, but definitely in that moment. What is the normal process for providing energy for fuel in muscle movement? This article will discuss three key levels of fuel supply to muscles as related to the environmental conditions present in the body at any given point in time.
The three fuel supply levels:
Level 1 Normal
Level 2 Stress
Level 3 Starvation
These levels are not completely independent of each other. One of all systems can engage in a continuum of varying percentages of participation, as needed, in the human biological fuel management of action. The musculoskeletal body needs fuel to move.
Fuel Supply to Muscles: Level 1 Normal
The most basic function of fuel supply to muscles is the majority of what is discussed in anatomy textbooks. The brain sends a signal to motor neurons. The body provides fuel and oxygen to create a contraction along the line of the intended motor neuron pathway to create targeted muscle movement. We eat food which is converted into fuel that is more easily used by the body, glucose, that travels through the vascular system. When the pancreas senses an increase in glucose in the blood, it produces insulin hormones that store the excess glucose into cells, including inside muscle cells. If the glucose level in the blood is too low, the pancreas emits glycogen hormones to ask the liver and other cells with stored glucose to release some reserves. The body’s goal in this normal process is to create an individualized homeostasis of supply on demand to provide fuel for standard movement activities. For example, short term (<20 minutes), fast twitch exercise starts by using carb loaded glucose stored inside muscle cells during rest periods, such as sleep. If we eat more than we move, storage grows. If we exercise using more calories that we eat, storage inside cells can be reduced. I would argue that a very large percentage of the nutrition and fitness industries focus in this space. That’s normal.
Fuel Supply to Muscles: Level 2 Stress
Stress of any kind of stress triggers a call to action for increased fuel mobilization for an immediate, action response that is designed to manage short-term stress incidents. The hypothalamus releases hormones which travel to the pituitary gland which travels to the adrenal gland which releases cortisol, the main stress hormone. Cortisol is primarily responsible for emergency glucose mobilization in the bloodstream. It also has the ability to limit functions in other hormone producing glands, such as the thyroid and pancreas, to limit their draw on energy supplies so that the body can focus on the emergency at hand. Signals are sent from the sympathetic nervous system to increase heart rate and blood pressure to rush increased fuel to muscles. Muscles in these circumstances are not fueled exclusively from fuel stored inside the muscle cell, but also by systemically flooding the muscles with super fuel. The fight or flight sympathetic nervous system situated just outside the vertebrae of the spinal column overrides the normal neurological communication to organs, and along with cortisol, prioritizes fuel needs for the emergency by slowing down non-essential functions such as decreasing digestion energy, putting reproduction on hold, and throttling the immune system. The short-term stress response is designed to focus immediate extreme power for literally seconds to lift a car or to run like the wind. Future body goals will have to wait until the emergency is over.
The most important transition to long-term stress management of fuel is the storage location of ‘rainy day’ energy potential. Excess fuel not used in a stress surge is converted to oil drops, not inside cells, but suspended in water in the body for deep storage. No matter what is causing the long-term stress, the adapted long-term stress system interprets the crisis as food scarcity, and throttles the insulin based repository system of storing fuel inside the muscles to prepare for the impending starvation mode. Muscles can weaken and become more susceptible to injury. The short-term primitive stress response in the body is very effective at managing extreme life threatening incidents. As humans have evolved, perceived stress that may or may not be treacherous, creates long-term stress anxiety using that same basic primitive system – and it lasts much longer than just seconds. Long-term stress prepares for the conversion to a third level muscle fuel management, starvation.
Fuel Supply to Muscles: Level 3 Starvation
There is an adaptation of primitive stress in humans for migration to find new food supplies during times of scarcity. This process resembles the blubber storage adaptation in a whale. Eat lots of krill, store oil reserves in blubber, travel thousands of miles using only deep fuel storage. Getting stuck in traffic may result in missing a dinner reservation, but the human adaptation for long-term stress fuel management interprets ALL stress as food scarcity, and changes the way the body stores fuel. Level 1 Normal stores fuel inside cells. Level 2 Stress uses deep storage solutions to hide fuel from muscles in droplets of oil suspended in water. The shift to migration mode in the body diverts focus of resources towards motion needed to migrate – walking. Perfect core posture in walking gives access to the fuel for the lower body muscles which are used to relocate to a better food supply. If the deep storage from stress is not used for migration, it’s time to buy a longer belt. Access to the deep fuel in an attempt to reduce fat can be very frustrating, but mainly because the deep fat does not readily respond to fast twitch exercise which burns fuel in Level 1 Normal. Unfortunately, doing fast twitch arm exercises while in Level 2 Starvation can put strain on upper body muscles that have been drained of fuel to reallocate potential energy to lower body slow twitch movement. A common manifestation of this is ‘skinny fat’ or an increase in belly fat even though the rest of the body is slender. The duress from stress demands sugar, and in a reduced glucose supply from food, cortisol can work as a biofuel scavenger wrangling glucose from inside dispensable muscles, such as the arms. Proteins and fats anywhere in the body can be redirected to deep storage, especially peripheral or recycled fuel on their way out as waste products through the intestines. The stress system will not let go of any usable resource. The conservative nature of starvation fuel usage insists that movement be low and slow. Sprinting is out; it uses a different type of muscle fuel, Level 1 Normal. Deep storage oil droplets are often warehoused in the belly, butt and thighs. The primary nerve centers responsible for muscles used in slow and steady walking for migration are the femoral and sciatic nerves which exit the spinal cord through the entirety of the lumbar and sacral segments of the spinal column. The lower body muscles need fuel for slow twitch migration, so it would make sense that just in time fat inventories are located close to their usage sites. Motor neurons for muscles pair with sensory neurons that provide feedback to changes in musculoskeletal position relative to gravity. Motor neurons for organs are provided feedback from the parasympathetic nervous system, especially the vagus nerve which will try to calm down the emergency status in the body. Adrenaline (epinephrine), noradrenaline or dopamine are neurotransmitters that exit the adrenal glands, located on top of the kidneys. They travel along neuron pathways throughout the peripheral nervous system to perform urgent tasks when the sympathetic nervous system is activated. The fight or flight system overrides the motor neurons of organs that are exiting the spine to increase heart rate, slow digestion, induce sweating, and many other visceral fine tuning to slow or excite fight or flight functions. The autonomic nervous system is predominantly discussed as a controlling force for smooth muscle present in organs. What if the neurotransmitters in the sympathetic nervous system also act as signaling molecules across a synapse, junctions points between neurons, where the target receiving molecule is a motor neuron for skeletal muscle activation during starvation? The adapted stress fight or flight system can use the sympathetic nervous system that travels throughout the body to directly contract muscles using Level 3 energy supply to muscles as a power line infrastructure for delivery of electricity that can directly excite musculoskeletal movement. Stress neurotransmitters access deep storage fuel near the neuromuscular junction of the stress movement targets in the lower body. The energy released from the oil reserves directly contracts the fascia surrounding the muscle as a crisis override operation when glucose from inside the muscle, Level 1 Normal, or potential power flowing through the vascular system, Level 2 Stress, is not available. Power extracted from deep fat oil storage oil droplets located near major nerve centers in the lower body allow walking in migration in the absence of regular food supply, aka starvation. This deep fuel release process may be responsible for the formation of ketone acids when the body is in pure fat burning mode. or ketosis. with the starvation component of intermittent fasting or for endurance athletes.
Fuel Supply to Muscles: Levels 1-3 Integration for Endurance Athletes
Endurance athletes train to use all three levels of fuel management to their fullest advantage for optimal performance.
Level 1 Normal – Eat food. Creatine and other amino acids and carbohydrates load inside muscle cells in preparation for tomorrow’s scheduled drills. Next day, begin movement from amino acids as a starter spark to begin burning carbs inside muscle cells for up to 20 minutes.
Level 2 Stress – Gradually activate the adapted stress system to increase glucose in the bloodstream to allow for extended performance. Train to increase oxygen efficiency to optimize the systemic muscle fuel supply and usage. Run science experiments in your body to see which external energy supplies can be turned immediately into fuel to sustain activity over time.
Level 3 Starvation – Encourage the sympathetic nervous system power lines to squeeze out deep storage oil droplets towards the end of the training to be able to endure just 10% more distance than last week. An ultra-marathon runner can lose 10 pounds of body fat in a single 100 mile run. Rest. Shut down endurance stress . Return to Level 1 Normal to recover.
Endurance athletes have the ability to run the continuum of fuel management across all three levels of fuel supply to muscles. I would argue that the base level in a high end athlete is Level 1 Normal with added training to utilize Level 2 and 3 to optimize performance. What if you are not normal?
Fuel Supply to Muscles: Levels 2-3 Injury Dysfunction and Stress
Any kind of stress can push your body into Level 2 Stress. Many clients I see with chronic injury often present with some degree of low grade stress in the physical body. An otherwise perfect life can still create anxiety for the fact that mechanical function in the body is not ideal. The sheer frustration of not being able to do your favorite activities after an injury can be debilitating. Stress fuel storage can increase weight, and the internet’s answer to weight loss is to try harder to be normal and do normal exercise.
Injury can automatically take you out of Level 1 Normal for the main reason that the stress created from chronic injury doesn’t allow the body to rest. The 24/7 disquieting nature of chronic pain or low grade musculoskeletal dysfunction will interrupt the ability of the muscle cells in the body to recover. When your body is in this mode, the first 20 min of fast twitch exercise can be really hard as internal muscle fuel is compromised. After the first 20 minute grind is over, the stress system starts kicking in to keep the body moving, but you won’t be setting any speed records. Glycogen hormone production in the pancreas to increase glucose in the blood would be a welcome participant.
Blood glucose needs to be high to manage that stress movement pattern. Extending the exercise to reach fat burning for fuel might happen, but if the core mechanics are off kilter from musculoskeletal imbalance, the body may not even be able to access the deep storage fuel in walking. A more likely scenario is that pushing high intensity exercise through stress will put more strain on the muscles and trigger more glucose activation and more deep storage. That can make you feel defeated.
Stress alone can provide enough sugar energy to train like an Olympic athlete. Most of us don’t do that much training. So the obvious answer for returning to normal is to reduce stress.
My medical massage practice focuses on reversing the effects of chronic injury in musculoskeletal movement patterns to allow a return to or to continue doing the activities that you love. Returning injured or scarred muscles to normal function can reduce the low-grade mechanical stress in the body.
Lymphatic drainage massage can help to remove enzymes tagged to muscles emitted from fat burning intended to reduce the uptake of fuel in the muscles to conserve fuel during times of stress. Drinking water, swimming or epsom salt baths can improve the flow of the superficial lymphatic system under the skin layers by flushing toxins and stress hormones into the waste system. Sweating can also directly remove toxins from the body.
A calm brain drives motor neuron control of normal muscle activity. Slowing down the effect of chronic frustration from not being normal helps keep anxiety from hijacking control of brain function needed to direct muscle movement. There are many types of counseling available for stress management to explore,
Scaling back workouts when in stress to primarily low and slow activities that are in direct contact with the ground’s gravity, such as walking with hiking poles to increase access to core strength, yoga, tai chi, meditation and other calming pursuits will literally burn fuel stored to manage stress. Standing or walking in good posture aligns the lower body to have clear access to stress fuel. Martial arts stances are specifically geared to call upon deep storage for superpower strength.
Short bursts of fast-twitch muscle activity like swimming, biking, and interval training, can increase the potential for an improved insulin response to increase carb loading inside muscle cells, especially within 30 to 60 minutes immediately following the exercise. As muscles begin a more normal recovery after movement, the potential for future higher intensity workouts is increased.
Deep breathing will turn on vagus nerve signals in the parasympathetic nervous system to tell the fight or flight system that the emergency is over.
A focus on balance should be done in every definition of the word. Here is a short balance in standing meditation based on Tai Chi principles that I developed.
The closer we get to Level 1 Normal, the closer we get to reducing chronic pain and anxiety from stress, and healthier access to fuel will keep muscles working as you are out enjoying life. I hope Jamal can overcome the electrical surge from the lightning strike or find a superpower where he can use the extra energy.
Author: Mary Bai of Tibialis, LLC is a Certified Massage Therapist practicing Medical Massage in Redwood City, CA.