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There are a lot of factors at play when trying to build muscles. You have to consider your diet, how much you work out, and even how much rest or sleep you get. One important factor people often fail to take into account when working out, however, is their hormone levels.

There are many hormones produced within the body that can affect exercise efficiency. Cortisol is just one in a long list of many but is one of the most essential. Keep reading to find out what makes this hormone special and why you need to take note of it when exercising.

What is Cortisol

What is cortisol?

Cortisol is a steroid hormone produced by the adrenal glands. The adrenal glands are endocrine glands that sit just above both kidneys. These glands secret cortisol, a glucocorticoid, and release it directly into the bloodstream in response to several conditions.

Hormones are chemicals produced by the body in one location and transported throughout the body to coordinate various functions. Steroid hormones are all derived from cholesterol, share a similar chemical structure, and affect body metabolism. Glucocorticoids are a type of corticosteroids, which are a type of steroid hormone that have various effects on the body, including modulating immunity, controlling fat and carbohydrate metabolism and controlling circadian rhythms.

Cortisol is the major glucocorticoid produced by the body. It is released under high physical and mental stress conditions and is the body’s major catabolic hormone.

Cortisol Effects on the Body

Effects of Cortisol on the body

Cortisol is the body’s major catabolic hormone. Hormones like testosterone and growth hormone help build tissue and are known as anabolic hormones. In contrast, cortisol’s summative effect is the breakdown of tissues.

Cortisol is also widely known as the body’s stress hormone because it is released in response to increased physical and mental stress levels. However, cortisol plays many more roles beyond merely regulating the body’s stress response. Some major roles of cortisol include;

Regulates stress response in the body

During periods of extreme physical or mental stress like prolonged fasting, extensive workouts, frightening encounters etc., the hypothalamus sets off a cascade that results in increased cortisol production. This increased cortisol stimulates gluconeogenesis (glucose production from other sources), causing increased blood glucose levels. Cortisol also stimulates the brain to take up more glucose during these periods while shutting down other functions deemed. unnecessary in that stress periods. Cortisol also stimulates the production of repair factors.

Regulates metabolism

When released, cortisol stimulates carbohydrates and fat to break down, creating a surge of energy in the body. Coincidentally, this process leads to increased appetite and more craving for sugary things, causing weight gain in the long term.

Suppressing inflammation

A normal cortisol level is essential to the immune response since it prevents the production of inflammatory mediators. However, chronic cortisol production under conditions of intense stress reduces the body’s response to cortisol’s anti-inflammatory action, resulting in a weakened immune system.

Regulating blood pressure

As part of its role in mediating stress response, cortisol causes an increase in heart rate and blood pressure. After the resolution of the stress, cortisol functions to bring the blood pressure back to its normal values.

Regulates glucose levels

Under normal circumstances, cortisol counterbalances the effect of insulin in regulating blood sugar. Cortisol raises blood sugar by releasing stored glucose, while insulin lowers blood sugar. Having chronically high cortisol levels can lead to persistent high blood sugar (hyperglycemia), causing Type 2 diabetes.

Controls Circadian Rhythm

Under ordinary circumstances, cortisol levels are lowest during sleep and peak in the morning right before waking up. This suggests that cortisol plays a significant role in the initiation of wakefulness and plays a part in the body’s circadian rhythm.

hypothalamus brain anatomy

Cortisol Regulation

The hypothalamic–pituitary–adrenal axis, is responsible for the secretion and regulation of cortisol in the body. When blood cortisol levels reduce, the hypothalamus is stimulated to release corticotrophin-releasing hormone (CRH), which in turn, causes the pituitary gland to secrete another hormone, adrenocorticotropic hormone (ACTH). The adrenal glands detect the increased level of ACTH and start producing cortisol in response.  The increasing cortisol levels go on to block ACTH and CRH release which then shuts off the cortisol production process. This is called a negative feedback loop.

Cortisol levels vary throughout the day, but typically have a diurnal rhythm, peaking in the mornings and dropping slowly throughout the day till it reaches its lowest during sleep. In people more active at night, the pattern is reversed. In people with a haphazard sleep cycle, cortisol levels likewise become haphazard.

Once the body is exposed to a stressful event, the hypothalamus shoots off and produces more CRH, which in turn stimulates much-increased production of cortisol to help address the stress. However, conditions, where cortisol levels remain persistently high or low, are problematic and must be addressed fast!

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High Cortisol and its effect

Some medical conditions, or use of certain medications may cause a prolonged increase in cortisol levels, known as Cushing’s syndrome. The symptoms associated with a prolonged increase in cortisol include;

  • rapid weight gain mainly in the face, chest and abdomen, while the arms and legs remain slim
  • high blood pressure
  • Osteoporosis (weak bones)
  • skin changes (bruises and purple stretch marks)
  • muscle weakness
  • mood swings, which show as anxiety, depression or irritability
  • increased thirst and frequency of urination.
  • Low libido
  • Irregular periods or amenorrhoea
Low Cortisol effects and symptoms

Low cortisol and its effect

Persistently low cortisol levels, known as Addison’s disease may be caused by pituitary or adrenal gland problems. Symptoms associated with this condition include;

  • Fatigue
  • Dizziness
  • Weight loss
  • Muscle weakness
  • Mood changes
  • Skin changes (darkening of regions in the skin)

 Relationship between Cortisol and Exercise

Cortisol levels and exercise performance are forever intertwined. Much as exercise affects cortisol release, so does the cortisol level affect exercise efficiency.

Cortisol is released in response to physical stress, which can come in a lot of forms, exercise being one. Now, cortisol release in exercise is actually beneficial, but only in the short term. The short burst of cortisol increases exercise efficiency by increasing blood glucose levels, brain glucose utilization and providing anti-inflammatory effects to promote rapid healing of torn muscles.

However, as exercise continues for longer, or becomes more intense, cortisol begins to build to unhealthy levels. Consistently engaging in high-intensity exercises leads to chronic cortisol buildup, worsening possible preexisting cortisol imbalance,

High cortisol levels are highly problematic for exercise performance. Persistently high blood cortisol results in;

  • Reduced immunity and increased inflammation
  • Reduced glucose utilization
  • Osteoporosis
  • Reduced testosterone and growth hormone release.

All of these conditions significantly reduce exercise performance and attempting to exercise under them worsens the stress, leading to more cortisol release. Thus, an endless negative loop.

When exercising or bodybuilding, testosterone and growth hormone significantly influence muscle growth and your ability to adapt to the exercise routines. Strong, dense bones over the healthy muscles are required to support heavy lifting and different exercise routines. Glucose utilization provides the energy needed for workouts or bodybuilding and an anti-inflammatory response helps to repair muscle and tissue damage that take place during bodybuilding or exercise.

By inhibiting all of these processes, cortisol excess adversely affects your ability to workout or bodybuild efficiently, striping you of the benefits.

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How to Control Cortisol Levels

Controlling cortisol levels is vital not just to boost exercise performance, but to maintain a more productive life generally. There are several strategies to ensure that normal cortisol levels are maintained.

1.   Dieting

Proper dieting is important in controlling cortisol release. Cortisol spikes occur in response to prolonged fasting. Thus, it is important to maintain a 3-square diet, with regular intervals between breakfast, lunch and dinner. Eating before an exercise routine in the morning is recommended to reduce cortisol gains. Furthermore, eating foods rich in antioxidants, with anti-inflammatory effects help controls cortisol levels. Such foods include; bananas, pears, green peas, dark chocolate etc.

2.   Sleep

Cortisol regulates and is regulated by the sleep cycle, being lowest during sleep. Getting adequate sleep effectively reduces how much cortisol is produced during wake times.

3.   Controlled exercise and bodybuilding

As pointed out, exercise and bodybuilding stimulate cortisol release. But in controlled portions, they release many other chemicals like endorphins, insulin and testosterone that counterbalance cortisol’s effects. A proportionate combination of exercise and nutrition allows the body to heal better and adapt better to stress in the long term.

4.   Stress Management

Cortisol is released in response to stress. Reducing the amount of stress you’re exposed to, whether physical or mental significantly reduces your cortisol release.

5.   Increase Magnesium Intake

Magnesium inhibits the production of ACTH in the pituitary, effectively blocking cortisol production. Magnesium also helps control the circadian rhythm, allowing you to get much-needed sleep to clear out cortisol build-up. Foods rich in magnesium, magnesium supplements and magnesium drugs will all effectively help lower cortisol levels.

6.   Adaptogenic Herbs

Adaptogenic herbs help the body adapt to stress easily. These herbs act by reducing cortisol release and stimulating other relaxing chemicals. Adaptogenic herbs like Ashwagandha, Panax ginseng and Passionflower are very effective in lowering cortisol levels and remedying anxiety. These herbs are often formulated as supplements for easy access. An example is the Ashwagandha Capsules.

7.   Cortisol Blockers

Cortisol blockers are drugs and supplements designed to lower cortisol levels. These drugs may have an effect in treating Cushing’s syndrome and are marketed for their benefits in enhancing exercise and bodybuilding, promoting weight loss, and relieving stress.

Cortisol blockers likely change cortisol production mechanisms in the body, leading to reduced cortisol production. However, abrupt withdrawal of these drugs may lead to a rapid, unnatural surge in cortisol production leading to illness. Hence, you should speak to your doctor before commencing a cortisol blocker. One prominent cortisol blocking supplement is the Cortibol Cortisol Manager and Blocker | Adrenal Extract Nutritional Supplements for Men and Women

Adrenal Fatigue and Cortisol

What next?

Cortisol is necessary for life, but only at normal levels. Excess cortisol can significantly impair exercise and bodybuilding efficiency, which are problematic for weight loss goals. Luckily, there are many natural means to control cortisol release, reduce stress, and live better. There are also supplements and drugs that reduce cortisol production and help with weight loss and stress management.

Ensure to speak to your doctor about your cortisol levels and how you can benefit from adaptogen supplements.


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