Getting your hydration and fuelling right in training and racing is very individualised and a crucial piece of the performance puzzle.
For hydration, it’s important to know in a given environment, how much fluid we lose per hour while exercising (we can calculate this by weighing ourselves pre and post a 1hr session done at a pre-determined intensity and noting heat and humidity).We also need to calculate, as accurately as possible, the amount of electrolyte depletion (particularly sodium) in that fluid loss. Both of these factors can differ greatly from athlete to athlete, are heavily dependent upon the environment which you are exercising in and also whether or not you are acclimated to the conditions.Fortunately, there is some testing you can do to easily and accurately work out these numbers. It’s crucial information to know, as minimising these losses definitely contributes to improved performance because muscle function decreases significantly after a certain point of fluid and electrolyte loss.
Another important element of performance is actually fuelling our effort. It’s well researched and recognised that our bodies can store enough carbohydrates in liver and muscle glycogen for 90 minutes to 2 hours worth of exercise, particularly at lower intensities. Exercising for longer than this or at a significantly high intensity, requires us to ingest carbohydrates to maintain performance. Once again our carbohydrate requirements are very individualised. It is also very intensity dependent, with higher intensity requiring more carbohydrates. There is specific testing you can do to work out your carbohydrate requirement as well at certain intensities but many athletes rely on a little bit of trial and error to drill down on this number. Using a race simulation later in your race prep is a great starting point for working out your carbohydrate requirement while operating at a certain intensity. Much of the research has definitely arrived at a few general rules that apply and it’s considered somewhere between 30g to 90g/hour is required, once you start operating at moderate intensities and particularly over 2hr in duration for the higher end of that range.As I mentioned above, this is very athlete dependent. There’s also been quite a bit of research to show that gut absorption (how much CHO can absorb through the gut and into your bloodstream) differs greatly from athlete to athlete and is the limiting factor in the process, so once again this highlights the importance of individualising your strategy and alsotraining your gut at the upper level of what you are aiming to ingest.
TAKE HOME MESSAGE: recognise the importance of practising your nutrition/fuelling strategy in a race simulation.When I was preparing for races, particularly in the longer distance events, I always sought the advice of nutrition experts when establishing my hydration and nutrition plan. We often spend so much time, effort and money preparing for these events, making sure our training is correct, having all the correct equipment, etc. so it just made sense to make sure that my planning around fuelling and hydration was just as intentional.
