BIG STRESS, little success

Stress is a major inhibitor of training results. With the prevalence of stress in today's society, it is important to understand how the hormone cortisol can affect your clients' progress, explains Janet Marshall.

High stress levels negatively impact training outcomes, often leading to frustration at an inability to build muscle or lose fat. To understand this scenario, firstly we need to understand what happens in the body during stress.
What is stress?

Stress is defined as a physiological or emotional response to change or threat. A threat can be emotional, psychological or physical; it can be real or imagined; and it can be in the past, present or future. Regardless, the body's response is the same in each situation.

Imagine you are a caveman. Picture yourself in the woods, foraging for food. You hear a noise and look up to see an enormous cave bear coming towards you... and it wants you for dinner! In this situation the body has a very primitive response called 'fight or flight'. In other words, you either stay to fight the bear, or run away to save your life.

These days we don't face bears, but we do face deadlines, traffic jams and information overload. While none of these stressors are life-threatening, the body responds the same way, providing you with the means for fight or flight by secreting chemicals that maximise your potential to save yourself.

Adaptation to stress

The ability to cope with stress is unique to each individual and is called adaptation. Physical and mental health strongly influence a person's ability to adapt to stress. Research into the side effects of chronic stress has shown that men are more likely to experience cardiovascular side effects, whereas women are more likely to experience depression or anxiety.

What happens in the body?

During times of stress, the sympathetic nervous system is stimulated, producing adrenaline and noradrenaline from the adrenal glands (located just above the kidneys). Your adrenal glands are also stimulated to produce a chemical called cortisol. Cortisol's job is to help the body respond to stress by maintaining blood pressure and cardiovascular function, by slowing down the immune system's inflammatory response and by regulating glucose levels and the metabolism of proteins, carbohydrates and fats.
Ideally, cortisol is raised temporarily (15 to 20 minutes) until the threat has passed, before returning to normal. However, in chronic stress situations cortisol levels remain high, meaning the body's fight or flight response doesn't switch off. If this continues, the body becomes resistant to cortisol's calming message – stress hormone levels remain high, and this is damaging to health. This resistance to the body's stress messages is a reason high blood pressure is often found in stressed individuals. Other effects of ongoing stress include:

  • Muscle loss
  • Bone loss
  • Decreased synthesis of protein
  • Decrease in basal metabolic rate
  • Decreased insulin sensitivity
  • Reduced levels of testosterone, DHEA (steroid hormone), growth hormone and TSH (Thyroid Stimulating Hormone)
  • Raised blood sugar
  • Suppressed immunity
  • Changes in memory and mood
  • Increased appetite
  • Carbohydrate and/or salt cravings.
  • How does this affect workout results?

Exercise can fool the body into thinking it is escaping the stressor (the bear). When we exercise, cortisol levels rise and energy is produced. The liver breaks down glycogen into glucose, fats are released from fatty acids stored in adipose tissue and amino acids are produced from skeletal muscle breakdown. The amino acids are either used for energy by the muscles or sent to the liver to be converted into glucose.

These processes are initiated at the start of a workout. As exercise intensity or duration increases, additional fuel is needed – cortisol levels continue to increase, providing further breakdown of glucose, fats and amino acids. Breakdown of fat and muscle protein in particular are increased in the presence of cortisol. Raised cortisol levels also slow post-exercise muscle recovery.
Problems arise when clients already have high cortisol levels before they even start to exercise. Exercise will raise their levels even higher, and in the stressed individual it takes much longer for cortisol to normalise: in fact, levels may not even become normal if the person is chronically stressed.

DHEA and testosterone decrease during exercise, increasing the ratio of cortisol to DHEA. This causes an increase in blood sugar levels due to raised gluconeogenesis (generation of glucose from non-carbohydrate substances) and a breakdown of muscle tissue.

This double-whammy effect of increased blood glucose and fats, side-by-side with decreased levels of testosterone and DHEA means that appetite increases, fat is deposited (usually around the abdomen) and muscle is broken down.

The body's fat storage enzyme

HSD (11 beta-hydroxysteroid dehydrogenase-1) is an enzyme within fat cells that functions to turn inactive cortisol (cortisone) back into cortisol. This sends a powerful signal to cells that store fat, especially abdominal fat, in which there are also a higher number of cortisol receptors. Abdominal fat is metabolically active, meaning it becomes almost like a separate organ of the body, secreting hormones, triglycerides and other biochemicals. This is why men who have big bellies also often develop 'man boobs': their bellies are producing oestrogen, the feminising hormone.

Questions for clients

If you have clients who are not achieving their fitness goals despite apparently sticking to their workout regimes and eating healthily, and you suspect the reason is stress, the following questions can help clarify the situation.

On a scale of one to ten, one being relaxed and ten being completely stressed out, how would you rate your stress level?
Generally, a score of 5 and above would be considered a level of stress that is negatively impacting health.

How long have you felt this level of stress?
The longer the duration, the greater the health consequence – three months or more is considered 'chronic'.

How often do you feel stressed?
If the client responds with 'often' or 'most of the time', their health is being negatively impacted.

What relaxes you?
If your client knows what relaxes them, encourage them to do it more often.

Do you take any medication for blood pressure?
If the client answers 'yes' it is often a sign that stress levels are high, and may be internalised (not expressed outwardly). A 'no' answer doesn't necessarily mean they are not experiencing stress – ask further questions.

How do you cope with stress?
Although a self-evaluation, an answer of 'I cope pretty well' or 'not very well' gives a fair indication of how well the client is managing their stress levels. Finding a way to cope with stress doesn't reduce the stress but it does decrease the health impact.

Do you experience heart palpitations?
A 'yes' can indicate high stress levels or other health issues. Encourage your client to be medically assessed.

Do you ever feel unable to cope?
If the client says they often feel weepy, angry or overwhelmed, this can indicate an inability to cope with stress.

Do you find it difficult to get to sleep or stay asleep?
The client may complain of disrupted sleep if they are experiencing high levels of stress. This can be temporary or may become chronic if not addressed.

Do you feel 'wired and tired'?
This description rings true for the client who is chronically stressed or is consuming too much caffeine.

If your suspicions of stress in a client have been reinforced by their answers to these questions, it could be advisable to refer them for salivary testing, which can present a clearer picture of their individual cortisol rhythm.

Cortisol and the diurnal rhythm

Cortisol is produced by the adrenal gland in a diurnal rhythm. That is, over a 24-hour period there is a pattern to its release. Ideally, cortisol levels are highest in the morning, peaking between 6am and 8am. This is the body's way of providing us with the best coping and energy-producing mechanism for whatever challenges the day brings. Over the course of the day, cortisol levels gradually decline, reaching their lowest at around 10pm. This is when the hormone melatonin kicks in, making us tired and sending the body signals that it's time to go to bed and sleep. Cortisol and melatonin oppose each other, so if you go to bed and your cortisol levels are still high, it will be difficult to fall asleep due to the inhibition of melatonin.

Referring clients for cortisol testing

The most accurate way to get a picture of the rhythm of a client's cortisol is to do a salivary test, either through a naturopath or an integrative medical doctor (a doctor that practices both complementary and traditional medicine). This involves collecting a small amount of saliva in a plastic tube four times over a 24-hour period; between 6am and 8am, midday, 6pm and 10pm. Saliva measures the delivery of hormone to the cells from the various reservoirs in blood. Because saliva reflects what actually gets into the cells rather than hormone which has not yet been delivered to the cells (as is the case with blood (serum) hormone levels), it is considered a more accurate reflection of tissue hormone that is bio-available (i.e. able to be absorbed and used by the body).

Despite this, saliva hormone measurements are only a guide, and the experience of the health practitioner and their understanding of the individual's other clinical signs is important.

What to do if your client is shown to be suffering from stress

A comprehensive approach, including diet, lifestyle and nutritional supplementation, combined with open three-way communication between the health practitioner, personal trainer and client, will achieve maximum results.

  • Talbot, S; The Cortisol Connection, Hunter House Inc Publishers, 2002
  • Ivy, J and Portman, R; The Performance Zone, Basic Health Publications Inc, 2004
  • Marshall, J. Signs and Symptoms for Personal Trainers, Lifestyle Practitioner Academy, 2011
  • Rocky Mountain Analytical Laboratories


Janet Marshall, BHSc (Comp Med), Adv Dip Nat, Dip Nut
From nurse to pathology technician, health science graduate to marketing executive, competitive tri-athlete to massage therapist and naturopath, Janet has a wealth of experience in health and fitness. She currently works as a naturopath at two Sydney health clinics and consults with personal trainers within the Sydney area. For further information visit