Fuelling training can be complex. There are a lot of opinions out there as to whether we should fuel training and how we should fuel it.
Should I ride fasted? Train low? Sleep low? Train low race high? Should I fat adapt? Should I train with 60-90 or 120g of carbohydrates per hour and which carbohydrates do I need? The options are endless, so how do I choose? Let’s clarify this a little for you.
Physiology 101: the body uses carbohydrates and fat for energy during exercise. Typically it uses a combination of both, with a much greater percentage of fats at low intensity and almost exclusively carbohydrates at high intensity. So the type of fuel you need really depends on the training session you are going to do.
So logic would say that if you are going to do a low intensity ride you either don’t need to fuel or fuel with fats and if you are doing a high intensity session you need to fuel with carbohydrates, but of course it is not that simple.
Research has shown that restricting carbohydrate intake before and during exercise enhances cell signalling, gene expression and modulates components of training adaptation and exercise performance. However, we also know that training with low carbohydrate availability results in shorter, less intense training.
Training with high carbohydrate availability has been shown to allow the completion of more work at a higher heart rate for longer and result in similar cell signalling.
So if the signalling is the same and I can go harder when fuelled, why would I even consider training fasted? Is it going to help my body composition? The answer to this question is pretty straight forward … NO. We know that riding fasted will not help you lose weight, typically we tend to compensate afterwards by either eating more or moving less and we are often not aware of this.
Training fasted or with restricted carbohydrates are strategies used to improve our metabolic flexibility, which is our ability to use both carbohydrates and fats efficiently during exercise. But just like you wouldn’t just do Z2 rides all the time, you would not train fasted all the time.
Impey and colleagues have published a seminal paper around Fuel for the work required that summarises the above beautifully, we want to use different fuelling strategies based on the type of training we are doing and the goal of that training session and overall training block. Fuel training that involves high intensity and or long duration. Choose selected training sessions that are low intensity and shorter in duration to complete with restricted glycogen stores.
Just like your training sessions differ, so should your fuelling. This can be complex to start with, but working with a performance dietitian can help you identify the best fuelling strategies for your training that are supportive of the adaptation you are seeking.
