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What is cortisol? What is cortisol? Cortisol, known as the regulator of immune response, is a hormone controlled by the adrenal cortex. This powerful hormone is also known as an adrenalcorticol hormone, a glucocorticoid and hydrocortisone or simply cortisone. Cortisol has a catabolic (muscle breakdown) effect on tissue and is associated with a decrease in anabolic (muscle growth) hormones like IGF-1 and GH. Thus reducing levels of cortisol is ideal for an athlete to achieve tissue growth and positive adaptations to exercise training. Playing many different roles in your body, cortisol can have a negative impact on sleep, mood, sex drive, bone health, ligament health, cardiovascular health and athletic performance, potentially causing fatigue and inflammation. Its primary functions are to increase protein breakdown, inhibit glucose uptake and increase lipolysis (the breakdown of fats). What does an increased cortisol level mean to me? While cortisol in normal amounts is necessary for proper metabolic function, a chronic elevated cortisol level has adverse effects on your health, mood, body composition and performance. Here's the cycle: elevated cortisol secretion from physical or mental stress causes fat, protein and carbohydrates to be rapidly mobilized in order for you to take action against the stressor. This is sometimes referred to as the 'fight or flight' response. The mobilization of these nutrients in addition to epinephrine and a number of other endocrine hormones allows you to take quick action when presented with stress. During this mobilization, cortisol and adrenaline increase while DHEA (Dehydroepiandrosterone) and testosterone decrease. A chronic elevated cortisol level causes your body to enter a state of constant muscle breakdown and suppressed immune function, increasing your risk of injury while reducing muscle. How do I know if my cortisol levels are high? Mood swings, lack of motivation to train, loss of muscle and loss of appetite are all symptoms of an elevated cortisol level. Sound familiar? That's right, overtraining syndrome. If you are not taking steps to modulate your cortisol, you are breaking down your muscle, storing fat and getting sick, all of which don't make for a fast racing season. A more scientific approach is to have your testosterone/cortisol or IGF-1/cortisol levels tested. An elevated ratio of cortisol over either IGF or testosterone is a sure sign of decreased exercise capacity and overtraining. There is also strong evidence that athletes exercising in a carbohydrate-depleted state experience greater increases in cortisol. What affects cortisol secretion? Stress, which includes trauma, infection, disease and exercise, is the primary factor that dramatically raises cortisol levels. Wait a minute, exercise is a stressor? High intensity exercise and prolonged exercise both increase cortisol levels, which remain elevated for about 2 hours following the exercise bout. Repeated exercise without appropriate rest results in chronic elevated cortisol. Additionally, poor diet, inadequate supplementation and lack of rest also play key roles in cortisol secretion. How does cortisol affect my endurance performance?It is only with chronic elevated cortisol levels that your performance will suffer, but the effect is dramatic. Excess cortisol suppresses your immune system, producing a greater risk of upper respiratory infections and depressed levels of testosterone. On top of that, your body will be in a catabolic state -- breaking down muscle and storing fat. In addition to reducing your muscle and getting sick, suppressed testosterone means suppressed recovery. Aerobic and anaerobic muscle fibers need time to repair and recover from hard workouts to improve their capacity to exercise. Elevated cortisol and suppressed testosterone do not allow you to maximize your recovery, leading to slower performance gains. A Swiss study of elite male cyclists suggested that ratios of anabolic to catabolic hormones (ie. testosterone/cortisol or IGF-1/cortisol) may be useful markers for the detection of overtraining (Hug et al. 2003). In fact, scientists use this Free Testosterone/Cortisol ratio to evaluate an athlete's training state. A ratio where cortisol is elevated indicates overtraining, so the modulation of this ratio can be key for those athletes who are susceptible to overtraining.
How can I modulate Cortisol? Cortisol can be modulated through rest, nutrition and supplementation. First, since repeated bouts of exercise cause chronic elevated cortisol, it is key to get plenty of rest between workouts. Double workouts in one day are detrimental if there is not sufficient rest between the workouts (see side bar by Sally Warner Ph.D.). Next, as mentioned earlier, depleted carbohydrates leads to higher levels of cortisol, so keep up your carb intake. Don't bonk! Finally, there are a number of supplements that are also helpful in modulating cortisol. A blend of high levels of B vitamins, branched chain amino acids, glutamine and key adaptogens like ginseng, rhodiola and ashwaganda all help you adapt to 'stress' by helping regulate the body's endocrine hormones also known as the 'fight or flight' response to stress. Recommendation: Since the scope of this newsletter is nutrition, we will detail our nutrition and supplement recommendations and briefly list lifestyle changes which help modulate stress. The most important step is to reduce any unnecessary stress in your life. Although sometimes the most difficult thing to do, it is also the most effective, so make sure to manage the stress that you cannot eliminate. Time management, yoga, and hobbies are some effective techniques. Complementary to managing stress, it is crucial to stick to a sensible diet. Poor nutrition -- including high fat or high protein diets -- can adversely affect cortisol control. In times of high stress many of us crave these types of meals which we know are detrimental to our health. It is also important to maintain carbohydrate intake that supports training hard and good health while doing so. A recent study by Green et al. (2003) supported carbohydrate intake during endurance exercise to reduce blood cortisol levels for up to 1 hour after exercise. A literature review of hormonal responses to exercise by Steinacker et al. (2003) suggested that with glycogen deficiency, cortisol levels are elevated and induce a "myopathy-like state" in skeletal muscle. And it's not only what you eat but when. Make absolutely certain you have breakfast, which will help regulate your blood sugar and your cortisol prior to workouts. In a recent paper by Dr. Mark Davis and Dr. Adrienne Brown, it was clearly demonstrated that ingesting carbohydrates during exercise modulates many of the endocrine hormones, including cortisol. To ensure that you do not deplete your glycogen stores, be sure to take in carbohydrates while exercising along with a high quality recovery drink with high levels of carbohydrates immediately following exhaustive exercise. The bottom line: do not attempt endurance training on a high protein, low carbohydrate diet -- it's a kiss of death (see sidebar by Sally Warner). A high dose of B vitamins and calcium can help regulate the endocrine hormones necessary for proper cortisol control. Supplementing with 4+ grams of branched chain amino acids (BCAAs) and 6+ grams glutamine following exhaustive exercise can have a dramatic effect on cortisol. In fact, in a 25-week study of intercollegiate swimmers the group supplementing with BCAAs and glutamine showed a significant decrease in serum cortisol. For added cortisol control, consider some herbal applications. Adaptogens are some of the more popular supplements that help with cortisol control, which include ashwaganda, rhodiola and ginseng. By definition, adaptogens help the body adapt to high levels of physical and mental stress. The result is a controlled 'fight or flight' response that helps modulate cortisol levels. Another class of herbs common in Traditional Chinese Medicine (TCM) directly and effectively modulate cortisol. Magnolia bark, theanine (from green tea), epimedium and tyrosine have shown promise in regulating cortisol. Ironman triathlete, cyclist and Ph.D. Shawn Talbott's recently released book The Cortisol Connection goes into detail on these and other TCM herbs. References: Bishop NC, Gleeson M, Nicholas CW, Ali A. Influence of carbohydrate supplementation on plasma cytokine and neutrophil degranulation responses to high intensity intermittent exercise. Int J Sport Nutr Exerc Metab 2002 Jun;12(2):145-56 Brenner IK, Zamecnik J, Shek PN, Shephard RJ. The impact of heat exposure and repeated exercise on circulating stress hormones. Eur J Appl Physiol Occup Physiol 1997;76(5):445-54 Cook NJ, Ng A, Read GF, Harris B, Riad-Fahmy D. Salivary cortisol for monitoring adrenal activity during marathon runs. Horm Res 1987; 25(1):18-23 Ding JH, Sheckter CB, Drinkwater BL, Soules MR, Bremner WJ. High serum cortisol levels in exercise-associated amenorrhea. Ann Intern Med 1988 Apr;108(4):530-4 Gleeson M, Lancaster GI, Bishop NC. Nutritional strategies to minimise exercise-induced immunosuppression in athletes. Can J Appl Physiol 2001;26 Suppl:S23-35 Green, KJ, Croaker, SJ, Rowbottom, DG. Carbohydrate supplementation and exercise-induced changes in t-lymphocyte function. Journal of Applied Physiology 2003 95: 1216-1223. Hug M, Mullis PE, Vogt M, Ventura N, Hoppeler H. Training modalities: over-reaching and over-training in athletes, including a study of the role of hormones. Best Pract Res Clin Endocrinol Metab. 2003 Jun; 17(2): 191-209. J Mark Davis, Adrienne S. Brown Carbohydrates, Hormones and Endurance Performance. Gatorade Sports Science Institute® 2001; 14 (1). Lac G, Berthon P. Changes in cortisol and testosterone levels and T/C ratio during an endurance competition and recovery. J Sports Med Phys Fitness 2000 Jun;40(2):139-44 O'Connor PJ, Corrigan DL. Influence of short-term cycling on salivary cortisol levels. Med Sci Sports Exerc 1987 Jun;19(3):224-8 Ronsen O, Kjeldsen-Kragh J, Haug E, Bahr R, Pedersen BK. Recovery time affects immunoendocrine responses to a second bout of endurance exercise. Am J Physiol Cell Physiol 2002 Dec;283(6):C1612-20 Steinacker JM, Lormes W, Reissnecker S, Liu Y. New aspects of the hormone and cytokine response to training. Eur J Appl Physiol. 2003 Nov 8 [Epub ahead of print]. Textbook of Medical Physiology; ninth edition. Guyton and Hall, W.B. Saunders Company, Philadelphia, PA Copyright 1996 Textbook Overtraining in Sport: Kreider R.B. ;A.C. Fry, and M.L. O'Toole, Human Kinetics; pgs 323 and 329. Copyright 1998. The Cortisol Connection. Shawn M. Talbott PH.D. Publishers Group West, Hunter House Inc, Alameda CA Copyright 2002 | |||||