Cortisol and Overtraining Syndrome: Why an Athlete Should Care

Jeffrey J. Rocco, MD

As an active athlete are you feeling tired and rundown?  Are you working harder, but going slower?  Don’t feel like training?  Feeling moody?  Getting sick?  Losing muscle, and storing fat?  If you are experiencing these symptoms, you may have elevated cortisol levels due to overtraining syndrome (OTS).

As the heat goes up this time of year, so do the density and intensity of race schedules.  The stresses of racing and training are building, and many athletes are wondering if they are experiencing OTS.  Chronically elevated cortisol levels may indicate an athlete is experiencing OTS.  Cortisol is a powerful hormone that is produced in the adrenal glands positioned on top of your kidneys.  Its primary role is to mobilize your body’s nutritional resources in stressful situations.  In short bursts, elevated cortisol is good because it elevates blood sugar levels to improve brain function and to prepare the body for action.  Cortisol levels typically increase in the early morning hours before waking.  This prepares your brain and your body for waking activities and helps get you out of bed.   Ironically, when this response is prolonged, memory and mental function are impaired (Taverniers 2010).  Cortisol levels increase in response to physiologic and mental stresses.  In conjunction with the release of epinephrine, many people refer to this as the fight or flight response.  Athletes typically experience this feeling on race day.  Cortisol’s role is to mobilize stored carbohydrates, catabolize proteins into glucose, and to mobilize stored fats.  Your body can use these nutrients to deal with the stressor, whether it’s a race or a saber-tooth tiger.

Chronically elevated levels of cortisol have a number of undesirable effects for athletes.  Elevated cortisol levels lead to a perpetual catabolic state where muscle is broken down, and fat is stored.  These effects are exacerbated when an athlete is depleted of carbohydrates. Supplying adequate carbohydrates during training protects against elevated cortisol levels.  Carbohydrates provide fuel for an athlete’s body to do work.  Because your brain requires glucose to function, when your body is starved of fuel, it will cannibalize lean muscular tissue to provide glucose for the brain.  The brain can only function on glucose and is not capable of metabolizing fat.  And while muscular tissue can be broken down into glucose, stored fat cannot be converted to glucose.  It would appear to be common sense that your body will experience less stress from training and racing if it has the nutritional building blocks it needs to repair and regenerate.

Decreased levels of testosterone in men, and decreased levels of progesterone and estrogen in women may further impair recovery.  While these hormones are usually thought of as sex hormones, they are also anabolic and potentiate recovery.  Chronic stress causes both an increase in cortisol and a decrease in testosterone, estrogen, and progesterone.  This can lead to amenorrhea in women, and stress fractures in both men and women.  Chronically elevated cortisol levels which are associated with overtraining lead to suppressed immune system function and reduced exercise capacity.  Sick, injured and slow is no way to conduct your season.

A training schedule that incorporates periodization allows time for the body to rebuild, and for cortisol levels to return to a normal state.  For best results develop a plan to mangage all systemic stress including work, lifestyle, diet and lack of sleep. Even adding several hours of recovery time between exercise sessions can reduce cortisol responses on double session training days (Ronsen et al., 2002).  Providing your body with a recovery drink immediately following exercise can jumpstart the rebuilding process, and make the most of precious recovery time.

Adaptogens, and Rhodiola specifically, appear to lower cortisol levels and improve the body’s response to the mental and physical stresses of training.  (Olsson 2009, Parnossian 2009, Zhang 2009)  A recent study investigated the effects of Optygen (which contains Rhodiola) in a group of collegiate distance runners over the course of a season.  As expected the stresses of a competitive season lead to a 36% increase in cortisol levels in the control group, while the runners using Optygen actually demonstrated a 26% decrease in cortisol levels. (Creer 2007)  The stress of training leading to chronically elevated cortisol can also have a negative impact on exercise capacity.  A study investigated the effects of Optygen in collegiate distance runners while preparing for the cross-country racing season.  The Optygen group showed a 42% improvement in time to lactate threshold suggesting that the reduction in cortisol leads improved physiological parameters. (Larson 2007)

Elevated cortisol levels are just the tip of the iceberg when it comes to overtraining.  The actions of cortisol are multifaceted and complex.  As an athlete, if you find your performance decreasing despite your hard training, perhaps it is because of your hard training that your performance is suffering.  Once you find yourself in this downward spiral, stop and take a deep breath. No, really, deep breathing can help to reduce stress. Reevaluate your diet before, during and after exercise.  Consider your rest and recovery time as an integral part of your training schedule.   Your body needs to be stressed to make performance gains, but it also needs time and proper nutrition to make those gains.  Use of adaptogens along with carbohydrate support and some  scheduling savvy may allow you to train harder with less stress, better performance and better health.

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