4.Cortisol

CATEGORY:

•Hormone

DEFINITION:

•Catabolic Steroid Hormone released by Adrenal Gland in response to mental & physical stress and low-Blood Sugar (see Insulin)

FUNCTION:

•Increases Blood Sugar and aids metabolism of Fat, Protein & Carbs

•Releases Amino Acids (from Muscle Tissue) used to synthesise Glucose in the Liver - raises Blood Sugar Level for brain energy...other tissues decrease use of Stored Glucose for fuel

-Combats stress from trauma, illness, fright, infection, bleeding, etc.

•Releases Fatty Acids (energy of Fat Cells) to increase Blood Sugar levels

•Helps deal with stress by shutting down unnecessary functions e.g reproduction, immune system...energy then available to deal with stress

•Suppresses pain

ACTIONS:

•Stimulates Gluconeogenesis (making Glucose) in Liver by Catabolising muscle tissue to release Amino Acids etc...depleting Amino stores

-Also utilises Fats

•Also involved in Glycogenolysis (breakdown of Glycogen in Liver and Muscles)

•Inhibits Insulin from shuttling Glucose into cells...net result is excess Glucose in the blood stream = good for fight or flight, but bad for daily life

•Inhibits uptake of Amino Acids into muscle cells (Protein Synthesis) making it hard to fuel muscles when levels too high for too long...stress of excessive Fasting and intense exercise

•Contributes to water retention

•Can negatively affect Testosterone levels

•Can cause intense hunger and food cravings

•When stress is chronic, Cortisol resistance leads to above problems

•Creates mood swings

FACTS:

•Levels can rise 50% after intense exercise

•Daily fluctuations in Cortisol are no concern, indicating a healthy Endocrine (hormone control) system...Chronic elevated Cortisol levels are a problem

•Cortisol decreases the production of Serotonin

•Chronic elevations inhibits the Immune System

-Decreases white blood cells and antibody formation

•Emotional/Stress induced eating leads Cortisol to partition extra calories (Fat) in the abdomen or stomach area

•High @ 06:00-08:00 - helps us to wake up and feel active

•Low @ 15:00-16:00

•Lowest @ midnight...rises throughout the night

-Natural levels of Cortisol are not elevated by reasonable non-chronic/acute elevators of the Hormone e.g. exercise

—Training at times when Cortisol is already elevated ensures a manageable hormonal effect...training at other times can solicit undesirable effects

MANIPULATION:

•Manage stress levels

•Presence of Glucose & Aminos in blood during workout reduces Cortisol affect of extracting them from liver & muscles

•Levels reduced by human contact

DIETING:

•Increased Stress Levels lead to catabolic release of Cortisol

•Increased on consumption of caffeine

•Affects Visceral (organ surrounding) fat rather than Subcutaneous fat (under skin)

•Can lead to high calorie food cravings

•Ingested Carbs assist with controlling cortisol whilst training (diagrams)

•Cortisol reduces Protein Synthesis and accelerates the process of breaking down Amino Acids into Glucose (Gluconeogenesis)

•When Muscle Glycogen concentrations are low, Cortisol is released and fuel use shifts toward Protein or Fat

-Long-term, excessive cortisol encourages Fat Synthesis and storage, and provokes appetite

—Importance of knowing when Glycogen stores are too low for too long so that a Feast can replenish them

—As BMI reduces and ratio of Muscle % to Fat % increases, more frequent Feasts are required

—If training, this phenomenon is of even greater importance

RELATED TO:

•Blood Sugar levels

•Insulin

•Amino Acids

•Gluconeogenesis

•Glycogenolysis

•Serotonin

NOTES:

•Might not be best to work out when levels are high!!!?

-Linked with Epinephrine!?!?!

•Can napping or FG exercise manipulate Cortisol in a positive way? Or is it negative?!?

•Carb and Amino Acid (protein) drinks during exercise promote muscle gain and recovery...having dark chocolate with nuts and raisins, seaweed etc may help during workout!!!!?

-Eliminates body going in to Starvation Mode...but IF refutes this!!!

•Is it best to workout stressed or calm....check 7minBody!!!

•Chronic elevated levels lead to osteoporosis due to catabolism of bone?!?!?

Changes in cortisol over a 24-hour period:-