How Many Days Should Cyclists Carbohydrate Load Before a Race?

It’s been well established that carbohydrate (CHO) availability (CHO stored in the body + CHO consumed in the diet) is essential to sustain medium-high intensity performance.

Therefore, riders must start races or demanding training sessions under ‘high CHO availability’.

With this in mind, riders will CHO load in the days leading into an important race or event.

The question is: what’s the best approach to CHO loading, with specific reference to the duration of the load?

Bissau et al. (2002) provided eight endurance-trained athletes with a CHO-rich diet over three days.

Over the three days, they consumed 10g/kg of high glycaemic CHO (700g CHO for a 70kg athlete) and asked them to remain inactive.

To assess how much CHO was stored in the muscle, they performed muscle biopsies before the load started, after day 1, and after day 3.

Unsurprisingly, after just twenty-four hours of CHO loading, maximal glycogen levels were achieved across all muscle fibre types. What’s more interesting is that when the athlete continued to CHO load for an additional two days, there wasn’t a further increase in muscle glycogen.

This suggests that an athlete can fully CHO load after one day of eating a high CHO diet when combined with inactivity. The following two days are, therefore, an unnecessary excess of calories.

Many athletes will perform some form of activity on race day-1 etc. This could be in the form of priming exercises, openers etc.

In this case, they’d need to add extra CHO to ensure there’s an excess supply at the end of the day. This means that you’ll most likely be in a calorie surplus to CHO load optimally.

I.e. 700g of CHO contains 2,800kcal. If this athlete was to follow a low fat intake (0.5g/kg) and high protein (2g/kg), this equates to 3,675kcal.

This is most likely a sizeable energy surplus and indeed a significant surplus if performed over three days.

- Coach Chris