Cycling Weekly Sportive Series nutrition partner Science in Sport gives you advice on Carb loading.
What is carb loading?
The basic premise is that along with a reduction in daily exercise levels, we should increase the amount of carbohydrate in our diet for the 1-3 days prior to an endurance event so that we increase the amount of energy (stored as muscle glycogen) in our muscles. Muscle
glycogen is the main energy source that fuels moderate to high-intensity exercise and depletion of glycogen stores during exercise is closely related to the onset of
Should I carb load?
Research over the last 40 years has consistently shown that carbohydrate loading delays the onset of fatigue during moderate to high-intensity exercise. So yes, if you have an
endurance event, it is worth carb loading.
Is there a downside?
In certain instances, yes there could be. For every 1 gram of glycogen stored in the muscle, 3 g of water are also stored. This means that your body mass may increase by 2-3% if you are fully carbohydrate loaded. For this reason you might feel heavier and more sluggish when you start. This isn’t a problem during endurance events like the sportive where you should be pacing yourself anyway, but it might hinder you in shorter, explosive events. For these situations, a ‘normal’ daily carbohydrate intake and a high carbohydrate pre-race
meal is therefore sufficient to fuel the intensity and duration of exercise.
How much should I eat to carb load?
The general rule of thumb is to consume 8-10 grams of carbohydrate for every kg of your body mass. For example, a 75 kg athlete would need to consume between 600-750 grams per day to achieve the rates of carbohydrate ingestion that are required to super-compensate muscle glycogen stores. This has been refined over time from the extreme methods of carbohydrate loading that were developed in the 1960s and involved a
7-day manipulation of exercise and diet. We now know that as little as 1-2 days of a high carbohydrate diet is sufficient to elevate muscle glycogen stores.
What should I eat and drink to carb load?
Carbohydrate loading should involve increased carbohydrate intake with the main meals of breakfast, lunch and dinner as well as high carbohydrate snacks and drinks throughout the day. So, look to increase your portions of easily digestible carbohydrate sources such as breakfast cereals, breads, rice, pasta and potatoes as well as energy bars (e.g. SiS GO Bars)
and drinks (e.g. SiS GO Energy). Indeed, the use of bars and drinks are a really effective and practical approach to increase carbohydrate intake as opposed to relying on bigger food portions that can often leave you feeling bloated.
What events should I carb load for?
Carbohydrate loading has generally been shown to improve performance in events lasting over 90 minutes, but this is influenced by the intensity of riding. For example, you’d benefit from being fully fuelled in a 25 mile time trial, but you might not need to for a steady 2 hour
ride. Certainly, any ride where you run the risk of hitting the wall, you’d benefit
from carb loading.