Download Australia's Best Supplement App
TRUSTED STORE SINCE 2004
TRUSTED IN OZ SINCE 2004
100% MONEY BACK GUARANTEE
SUPER FAST DELIVERY
SUPER FAST DELIVERY
EAST & WEST COAST DISPATCH
1000's of articles
THOUSANDS OF ARTICLES
WRITTEN BY INDUSTRY PROS
FREE WORKOUT VIDEOS
 FREE WORKOUT VIDEOS
 OVER 10 MILLION YOUTUBE VIEWS

Cortisol Defined

Cortisol or hydrocortisone is produced by the adrenal glands (situated above the kidneys). It belongs to a group of steroid hormones (made from cholesterol) called glucocorticoids and plays an important regulatory role in ‘housekeeping’ functions (e.g. maintain optimal blood glucose levels during fasting) and the immune system (e.g. allergies, asthma, autoimmune diseases). Cortisol levels peak in the morning, fluctuate throughout the day with stress and reach their lowest at night. Excess cortisol in the blood (hypercortisolaemia) is seen to cause a progressive decline in the muscle’s protein building ability, thus leading to loss in muscle mass and weakness. Variations in hormone levels have been known to predict the catabolic (breakdown) and anabolic (growth) state of our body adapting to stress and recovery from training sessions. Generally, the testosterone to cortisol ratio (T:C) is used. Higher testosterone indicates an anabolic state whilst higher cortisol indicates overall catabolism.

Cortisol & Bodybuilding

Exercise especially resistance training is important in promoting anabolism which increases muscle protein synthesis (MPS). Although there is an overall increase in protein synthesis, our muscles still remain in a catabolic state without adequate nutritional support. Thus, nutritional supplementation is critical to all phases of training as it can encourage an anabolic environment in response to endurance or resistance exercises. A combination of carbohydrate and protein alone has been demonstrated to reduce cortisol levels whilst increasing insulin levels and growth hormone levels after exercise. Furthermore, it is found that there is a reduction in muscle damage and increased production of muscle proteins. Essential amino acids (EAAs) supplementation has been shown to stimulate MPS thus inhibiting undesirable losses in muscle mass, as has the mother of all bodybuilding amino's L-Glutamine.  Coupled with another study demonstrating the beneficial effects of branched chained amino acids (BCAAs) on muscle, these supplements which reduce muscle damage would ultimately promote endurance to high-intensity training and subsequent rise in testosterone levels.

Baty, JJ et al, 'The effect of a carbohydrate and protein supplement on resistance exercise performance, hormonal response, and muscle damage' (2007) 21(2) The Journal of Strength & Conditioning Research 321hgh.org,
Glucocorticoids Cortisol
(2010)  <http://www.hgh.org/Endocrine-System/Glucocorticoids-Cortisol.html>

Paddon-Jones, D, 'Interplay of stress and physical inactivity on muscle loss: Nutritional countermeasures' (2006) 136(8) Journal of Nutrition 2123
Paddon-Jones, D et al, 'Atrophy and impaired muscle protein synthesis during prolonged inactivity and stress' (2006) 91(12) Journal of Clinical Endocrinology & Metabolism 4836
Peeters, G et al, 'The relationship between cortisol, muscle mass and muscle strength in older persons and the role of genetic variations in the glucocorticoid receptor' (2008) 69(4) Clinical endocrinology 673
Sharp, CPM and DR Pearson, 'Amino acid supplements and recovery from high-intensity resistance training' (2010) 24(4) The Journal of Strength & Conditioning Research 1125
Storer, TW et al, 'Changes in muscle mass, muscle strength, and power but not physical function are related to testosterone dose in healthy older men' (2008) 56(11) Journal of the American Geriatrics Society 1991

More Great Reading
Carbohydrates
Carbohydrates
Essential Amino Acids (EAAs)
Essential Amino Acids (EAAs)
Branched Chain Amino Acids
Branched Chain Amino Acids
Glutamine
Glutamine
The Best Protein Powder
The Best Protein Powder
10 Days of Reduced Sugar Benefits Obese Kids
10 Days of Reduced Sugar Benefits Obese Kids