Carbohydrate Tricks Brain To Keep On Going During Exercise  


With the New Year here, the trusty carbohydrate is probably one of the food groups that are reduced in order to promote weight loss, and particularly, fat loss. In most cases this is entirely justified, but quite often carbs (in one form or another) are neglected from the diet unnecessarily. With every macronutrient, there are better sources of them than others, and this has never been truer than with carbs. Carbs are everywhere in the diet, processed and pre- packed foods are crammed with them (in general), takeaways are laden with modified forms of sugar, whilst regular table sugar i.e. sucrose is still being poured onto sugar packed cereals and into teas and coffees!  Here in lies the problem for carbs, they are absolutely integral to the diet… but not all carbs are created equal.

Carbs and Exercise

The relationship between carbs and the regular sedentary person, and the recreational or professional athlete is different. Carbs make for an integral ergogenic aid for athletes, even sucrose has its place in an athlete’s diet. It all comes down to carbohydrates glycaemic index i.e. the rate at which a carb is broken down and causes a glycaemic response (rise in blood sugar), and the timing of this sugar spike. An athlete can cleverly harness the rapid release of energy from carbs when exercising, so that it delivers a hit of energy and reduces perceived exertion. A comparatively sedentary person may find that the same amount of sucrose (for example) consumed over the day causes a rise in body fat and reduces conditioning.

Carbs and exercise

Gant, (2010) asserts that ‘the presence of carbs in the mouth can immediately improve physical performance’. This gets straight to the point, and at the time, was very interesting because it states ‘in the mouth’, meaning the carbs don’t necessarily have to be digested in order to improve performance. Nicholas Gant is a renowned expert in carbohydrate metabolism, and this statement was continually backed by further research today. Phillips, Findlay, Kavaliauskas, and Grant, (2014) demonstrated similar findings in their recent publication in the Journal of Sports Science and Medicine. Over the years, findings have consistently found that carb intake during exercise is highly effective due to its potential glycogen sparing properties, its ability to maintain blood glucose concentration during exertion and because it increases the rate of carb oxidation in latter stages of races. The benefits seen here are attributed to carbs direct energy delivery, whereas the findings in the abovementioned papers demonstrate a more central effect (working on the brain).

Studies as far back as 2001 noticed central effects of consuming carbs, so more recent studies looked into the ‘mouth rinse’ technique which see’s athletes sip a carb based drink and spit it out a few seconds later. The studies found that introducing sweet and non-sweet carbohydrate into the mouth activated taste cortices in the orbitofrontal cortex of the brain (Chambers et al., 2009; O'Doherty et al., 2001). It is thought that this brain region may trigger other regions to release ‘feel good’ hormones and trigger ‘rewarding stimuli’. The effects of this was that athletes were able to increase their peak force during the latter stages of a race and/or exercise with only a few minutes/ reps of exercise to go.


Gant, N., Stinear, C, M., Byblow, W, D. (2010). Carbohydrate in the mouth immediately facilitates motor output. Neural Mechanisms of Ingestive Behaviour and Obesity. Retrieved 5th January, 2015, from
Phillips, S, M., Findlay, S., Kavaliauskas, M. & Grant, M, C. (2014). The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint. Journal of Sports Science and Medicine. Retrieved 5th January, 2015, from




About the Author

Job Role Qualified Dietitian and Sports Nutritionist Qualifications BSc (Hons) Sports Science | BSc (Hons) Dietetics Tom has always participated in sport both recreationally and competitively which led to an unquenchable thirst for information on anything health, nutrition and fitness. After leaving school Tom went on to play for a football academy during which time he studied Sport and Exercise Science. From here he went on to study a BSc (Hons) Sport Science at UEA followed by his second BSc (Hons) degree, this time at the University of Hertfordshire studying Dietetics. Tom has worked in the fitness, educational and clinical nutrition industry starting out at David Lloyd Health and Leisure Clubs. He then went on to work as a Dietitian (RD) in the NHS, during which time he conducted clinics for healthy eating, weight loss and weight gain, as well as specialised consultations on Diabetes, IBS and Coeliac disease to name a few. He has vast amounts of experience at devising diet plans and supplement regimens, as well as working in the community with schools and competitive athletes. As Head Nutritionist and Supplement expert at Discount Supplements Tom is here to provide current and evidence based health and nutrition information to help you reach your health and fitness goals!
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