By Matthew Burrell

Matthew Burrell N.D.
Naturopath and Neuromuscular Therapist

Are you finding that you are less inclined to exercise as the weather becomes cooler and the days shorter?

This is the reality for a lot of people, and you are not alone in feeling this way. 

But have you taken a moment to really understand what is the driver behind your reduced exercise motivation? This cause of this could be from Seasonal Affective Disorder (SAD).


Image: Jessami Kingsley


The term Seasonal Affective Disorder (SAD) explains the biological changes believed to be caused by the reduction in light exposure that occurs during seasonal change.(1) The reduction in natural light exposure affects your circadian rhythm and leads to reduction in serotonin and melatonin often resulting in sleep disturbances and a general feeling of lowered mood.  SAD typically occurs during specific seasons, most commonly in autumn and winter months.

Lack of motivation is not always a result of lack of desire. Reduced exposure to light can often leave you feeling lethargic and tired whilst also reducing your body’s ability to make vitamin D. Vitamin D  is has a powerful impact on mood, inflammation, resistance, gastrointestinal function and bone health.

When energy levels are affected, it also reduces your motivation to exercise. When exercise is reduced the production of many neurotransmitters or happy hormones are impacted. Dopamine (DA), noradrenaline (NE), and serotonin (5-HT) are the three major monoamine neurotransmitters that are known to be modulated by exercise.

Dopamine- is a chemical messenger in the brain that helps transmit signals between nerve cells. It plays a crucial role in various aspects of brain function and influences several processes in the body. Dopamine plays a role in how we feel pleasure. It’s a big part of our unique human ability to think and plan. It helps us strive, focus, and find things interesting (2).

Noradrenaline- is a neurotransmitter and hormone that plays a crucial role in the sympathetic nervous system, which is responsible for the body’s ‘fight-or-flight’ response. It is synthesised from dopamine and acts as both a neurotransmitter in the brain and a hormone in the body.

Serotonin- is involved in various physiological processes and plays a crucial role in regulating mood, emotions, sleep, appetite, and other functions in the body. Serotonin helps to regulate and stabilise mood, and imbalances in serotonin levels have been linked to mood disorders such as depression and anxiety.

Many systems in our body work to a circadian rhythm through a control centre in the brain called the hypothalamus. Under the influence of light and dark, the hypothalamus directs different functionality in the same way that a flower opens during the day to capture the sunlight and closes at night to protect itself. When our bodies are in tune with a circadian rhythm they function optimally.

The good news is that when you exercise in sunlight it increases your motivation to exercise again and again thus compounding its favourable effects.

As with anything in life, there needs to be a level of enjoyment or accomplishment. Exercising for the sake of it will see your motivation wander.  Therefore aim to find an exercise that you enjoy and set small achievable goals to keep you on track and reduce the lapses in motivation. Exercise does not have to be a solo affair.  Join a team, take a class such as Yoga, Pilates or a Running Group. This may be all it takes to keep you on track, particularly in the cooler months.

“We are less likely to let others down than to let ourselves down.”  (Jim Fortin)


  • Ensure you are getting ideally 7-8 hours of sleep a night.
  • Upon waking expose yourself to natural light to regulate your circadian rhythm.
  • Join a team or group activity
  • Pick an exercise that you ENJOY
  • Set small achievable goals and work towards them
  • Diet is incredibly important. Eat foods that are warming and nourishing and sustain you for longer
  • Where possible, get outside if the sun is shining and gain exposure to sunlight and vitamin D


  • Maintain body composition
  • Reducing fatigue and improving energy levels.
  • Stress management (serotonin, endorphins)
  • Immune enhancement
  • Mood regulation
  • Improved sleep quality

It’s important to note that while exercise can be extremely beneficial for SAD, it should be used as part of a comprehensive treatment plan. If you suspect you have SAD or are experiencing symptoms of feeling down, it is essential to consult with a healthcare professional for an accurate diagnosis and appropriate treatment options.

Wishing you a great week ahead.


  1. Nevarez et al. (2022), ‘Should clinicians and the general population be concerned about seasonal affective disorder in Australia?’ Med J Aust, 216: 507-509. 
  2. Cristol (2021) WebMD ‘What is Dopamine’
  3. Springer (2023) ‘Impact of exercise on brain neurochemicals: a comprehensive review’ DOI 10.1007/s11332-022-01030-y
  4. Health direct (2021) ‘Seasonal Affective Disorder (SAD)’
  5. Suni and Dimitriu (2023) Sleep Foundation ‘What it is, what shapes it, and why it’s fundamental to getting quality sleep.’