Sport / Science

Our Changing World – Exercise and brain health

15:35 pm on 23 August 2023

Dr Kate Thomas is a self-described “exercise evangelist”. An exercise physiologist, she spends her time researching the impacts exercise has on the body.  

But she also practises what she preaches.  

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Race director Terry Davis with Kate Thomas at the finish line. Photo: Claire Concannon / RNZ

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Based at the University of Otago, Kate is investigating what energy sources the brain uses when you put the body under stress due to exercise and/or fasting. While glucose is the preferred energy source for the brain, it can switch things up if glucose is depleted, and this opens different metabolic pathways and products.  

Kate monitors data during an exercise experiment. Photo: Claire Concannon / RNZ

In particular, Kate is trying to figure out what combination of fasting and exercise might trigger release of a protein called BDNF – brain-derived neurotrophic factor. BDNF plays a role in preserving existing nerve cells and encouraging the growth of new ones. Our levels of BDNF decrease naturally as we age, and in some chronic neurological conditions such as Parkinson’s disease.  

Study participants are asked to do a series of four trials – the hardest of which involves a three-hour cycle and a three day fast – while Kate monitors effort, blood glucose, products of metabolism and cognitive ability. In this mechanistic study, Kate is “pulling the levers” as she terms it, to figure out which conditions promote greater production of BDNF.  

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