Mental Workout


Lucy is 46 years old and married with three children. She has always been active and enjoyed life, but things took a wrong turn when her husband was made redundant at work, putting the family under financial strain. For the next six months, Lucy undertook full-time cleaning work while her husband searched for another job.

With the change, Lucy found herself struggling to look after her family and get all the housework done, often crawling into bed after midnight. In the morning, she would wake feeling tired, irritable and argumentative. She would regularly skip meals but consume more junk food and started to put on weight as a result. Social outings and their annual end-of-year holiday were also cancelled due to the financial pressure.

After a few months, Lucy came to see me with symptoms of depression and anxiety. Over the next nine months, she partially responded to a number of antidepressants and her husband found work again. How-ever Lucy never felt the same and still struggled with her sleep, energy and mood. Her concentration and memory were also impaired, leading to a lot of frustration, with thoughts that she was perhaps losing her mind.

Things worsened the next year when her father, who was in his sixties, had a heart attack, which resulted in a prolonged hospital admission. Concerned about her own health, Lucy consulted her GP, who after an examination and investigations, told Lucy her weight, blood pressure, cholesterol and sugar levels were all elevated, putting her at increased risk for a heart attack. Lucy decided to immediately start on an exercise program, even signing up for a personal training session once a week.

Soon, Lucy’s weight began to reduce and her blood pressure lowered. But even more noticeable were the improvements in her sleep at night and how refreshed and energised she was at waking. She noticed her anxiety and irritability slowly reduced, her mood significantly improved, and she could think more clearly and remember things better. Over the next few years, Lucy kept up her exercise program and told me she felt better than she could remember. We managed to reduce and then stop her antidepressant medications and she now only sees me once a year for a check-up.

The physical health benefits of exercise are very well known and documented. They include:

  • Reduction in weight
  • Reduction in blood pressure
  • Reduction in cholesterol
  • Improved immune system functioning
  • Increased bone density
  • Decreased risk of diabetes
  • Decreased risk of cardiovascular diseases such as heart failure and stroke
  • Decreased risk of almost all cancers.

However, what is now being increasingly understood are the psychological benefits of exercise. To date, there are more than 200 published scientific articles confirming beneficial effects such as:

  • Increased endorphins in the brain leading to a feeling of wellbeing
  • Decreased stress chemicals in the body, like adrenaline and cortisol
  • Increased core body temperature, which has a calming effect
  • Relieving of muscle tension
  • Improved sleep at night
  • Building up of energy levels and alertness during the day
  • Improved self-esteem, confidence, sense of mastery and control
  • Improved ability to think clearly, concentrate and remember things
  • Increased interaction with others, which stops the feelings of isolation
  • An effective barrier to dysfunctional thinking such as rumination.

Evidence is also mounting that shows how regular aerobic exercise both prevents and assists in the treatment of mental conditions such as depressive disorders, anxiety disorders, drug addictions, bipolar disorders, psychotic disorders, attention deficit disorders and Alzheimer’s dementia. There are several reasons for this:

Neurotrophic effects

Aerobic exercise promotes adult neurogenesis by increasing the production of neurotrophic factors, compounds which promote the growth or survival of neurons that:

  • Results in increased signalling in the brain and body
  • Mediates some of the effects of the growth hormone to control body growth and remodelling
  • Promotes blood vessel formation and increases brain blood volume.

Structural growth

The various functions of the brain structures that show exercise-induced increase in grey matter volume include those:

  • Required for the cognitive control of behaviour, particularly working memory, attention control, decision-making, cognitive flexibility, social cognition and inhibitory control
  • Responsible for reward perception, motivation and positive reinforcement; implicated in addiction disorders
  • Responsible for storage and consolidation of declarative memory and spatial memory; implicated in depression
  • That motor function and learning
  • Responsible for stimulus-response learning and inhibitory control; implicated in Parkinson’s disease, Huntington’s disease and ADHD
  • Responsible for sensory perception, working memory and attention. Additionally the left and right halves of the prefrontal cortex, which is divided by the medial longitudinal fissure, appear to become more interconnected.

Psychological stress and cortisol

Psychological stress induces the release of cortisol, and prolonged exposure to high levels of it causes impairments in cognitive control and has neurotoxic effects in the human brain.

Aerobic exercise stimulates cortisol secretion in an intensity-dependent manner. This means aerobic exercise increases physical fitness and reduces the biological response to the psychological effects of cortisol release and increased heart rate.


Continuous exercise can produce short-term euphoria, an affective state associated with feelings of profound contentment, elation and wellbeing, which is colloquially known as a “runner’s high.”

Current medical reviews indicate that several endogenous euphoriants cross the blood brain barrier to act in the central nervous system, creating these feelings of euphoria. These include:

  • Stimulants that function as endogenous amphetamine
  • Receptors that in turn produce euphoria and pain relief
  • Glutamate, one of the most common neurochemicals in the brain, is an excitatory neurotransmitter, levels of which are normalised by exercise.

So as the saying goes, “If you don’t make time for exercise now, you’ll have to make time for being sick later.”

It’s an adage that doesn’t simply apply to your physical health, but your mental wellbeing as well.

Mental Workout2

How to Exercise

Your heart rate

Do aerobic exercise so that your heart rate is 60–90 per cent of its maximum. A simple way to calculate your maximum heart rate is to deduct your age from 220. So if you are 50 years old, your maximum heart rate is 170 (220-50) beats per minute. 60–90 per cent of your maximum heart rate would be 102–153 beats per minute. Measuring this should be easy, thanks to the many options of electronic wrist devices available to monitor your heart rate. When you are exercising at this intensity, you will be sweating and finding it difficult to talk because you are breathing fast.

How often?

The amount of weekly exercise you need depends on how much better you want to get at it. Obviously, the more you exercise, the better you get. The current recommendations are for a minimum of 30 minutes a day, five days a week. Regularly review and upgrade your exercise program. As you get more fit and healthy, your exercise tolerance increases and you’ll need to increase the intensity to ensure you get the maximum benefits. This means upgrading from walking to running or swimming, hiking, doing aerobic classes at a gym, or lifting weights.

When to exercise?

Generally, the morning is the best time to exercise as the energy-enhancing and mood-enhancing effects will last all through the day. However, if you tend to have bad habits in the afternoons and evenings such as overeating, drinking alcohol or smoking cigarettes, then exercising during this time may have a double benefit for your health.

Getting in the habit

Make exercise enjoyable. Exercise with a companion or a pet, listen to music, make a game out of the exercise or play an individual or group sport. Get some sunshine outdoors.

Be accountable. Write it up on the wall at home and at work and tell family and friends about what you have planned and ask them to check on your progress. Additionally, there are a number of mobile phone apps that provide positive or negative reinforcement strategies that can keep you motivated.

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