What Amount of Fuelling do I need?

Sports nutrition is applicable to athletes at all levels, in some form. It will differ greatly from individual to individual and there is no set rule that will apply to everyone for how and when to take on nutrition. Humans, however, are all built in the same way; all will burn energy, and all will need to replenish depleted energy stores. Professional athletes are no different to this; they are just extremely fine-tuned examples. At the same time the largest improvements can be in athletes that have a lower fitness level because they are less efficient and rely heavily on carbohydrate stores for energy. 

Livers of trained subjects are also better at being able to convert lactate and amino acids to glucose that can allow higher levels of blood glucose levels during exercises (1). This means that untrained athletes have to take their energy from carbohydrate stores (either stored or taken on board through energy drinks etc.). 

As a general rule of thumb, we would advise the following: 

Activities under 90 minutes in duration

Activities under 90 minutes in duration can be sustained without depleting your energy stores (carbohydrates) sourced from dietary intake. However, the body will need rehydrating and the electrolytes (sodium, calcium, potassium and magnesium) in your system replacing, during and afterwards. This is where an electrolyte sports drink can help instead of water. See below. 

Activities 90 - 120 minutes in duration

Activities 90 - 120 minutes in duration will begin to deplete carbohydrate stores and energy levels / performance may drop. If your carbohydrate levels continue to decrease, your muscles are forced to rely on fat for fuel - this is commonly referred to as ‘bonking’ or ‘hitting the wall’. Your focus should be on hydration and energy replacement throughout. By taking on carbohydrate in the early – mid stages of the session, your body should be able to call on this energy towards the latter stages and therefore avoid the drop in energy / performance. Additionally, this will assist in improving how you feel, post-exercise. 

Each duration requires its own strategy for fuelling

Each duration requires its own strategy for fuelling

Longer Events

If you take part in longer events, you should already have some knowledge of what works best for you in terms of staying hydrated and fuelled for the duration. Again, your focus should be on hydration and energy replacement and there are a variety of ways of achieving this ranging from solid energy food to energy gels to powder drinks. You will need to invest some time into researching what works for you especially when considering caffeine. Hydration is important but there will be a limit (Said to be between 600-1300ml/hour when running) as to how much liquid you can take on board before potentially feeling bloated. Energy gels are a good way of topping up carbohydrate stores without having to ingest so much water. Solid foods are another good way of topping up carbohydrate stores without the extra water intake, but they can be cumbersome to carry if running, for example. What is the best form of nutrition for you? Solids v liquids? Look into this blog.


(1) Bergman, Horning et al. 2000; 

Bergman, B.C., Horning, M.A., Casazza, G.A., Wolfel, E.E., Butterfield, G.E., Brooks, G.A. (2000). Endurance training increases gluconeogenesis during rest and exercise in men. American Journal of Physiology 278, E244–51