What is carb loading?

Carbohydrate loading is the strategy used prior to endurance competition to top up glycogen stores in the muscle and liver. When done properly, the athlete gives themselves the best chance of performance success by keeping fuel stores in the muscles to a point of ‘supercompensation’ for use throughout a race. Carb loading can also be beneficial for athletes who have multiple events within a short time period such as 2-5 day tournaments. 

How does it work?

For endurance events, carbohydrates are our preferred fuel source (see fasted cardio). Our bodies break down carbohydrates into sugars that enter the blood stream. They are then transported to working muscles to provide energy. Topping up these carbohydrates stores prior to race day has shown to be beneficial for postponing fatigue in events lasting over 90minutes and hence show small improvements to performance (~2-3%).  This is where the ceiling comes in for the benefit of carb loading. We can only store so much in our body prior to the start of a race and carbohydrate depletion is usually seen at the 60-90 minute point. If you've set yourself up well BEFORE a race, the importance then lies with your nutrition plan during the race (see fuelling mid race). Among other things like dehydration, carbohydrate depletion is one of the most likely causes of fatigue in endurance events.

Is carb loading just pasta the night before?

While this has become one of the easiest ways to identify carbohydrate loading, there is more to unpack and understand. Carbohydrate loading has shown benefits in the 2-3 days leading into an event (without much added benefit to doing it any longer). It also has more effect when activity is lighter during these days which is often the case if you are utilising a taper week. 

Carbohydrates come in many forms and if you're being conscious of what you're eating in race week, you're more likely to set yourself up for success. Rice, bread, pasta, potatoes, yoghurt and noodles are just some other carbohydrate options which can be worked into a specific diet for an athlete prior to racing. 

How much should I be aiming for?

You can work out your intake with the rough calculations below. As you can see, females require slightly less to see the benefits of carb loading.
Males: 7-10g Carbs/kg/day (Roughly 525-750g carbohydrates per day for a 75kg athlete)
Females: 5-8g Carbs/kg/day (Roughly 300-480g carbohydrates per day for a 60kg athlete)

Carbohydrate loading is often mistaken for opening up the buffet and letting loose. It shouldn't be an excuse to eat anything and everything. It still needs to be a conscious approach to intake during race week. Be mindful that large amounts of high fatty foods and high fibre foods in the lead up to a race can compromise performance benefits or lead to gut discomfort on the day (more on this in future posts).