Carb loading for athletes

You have probably heard of the term “carb loading”. This strategy can be used to optimise muscle glycogen stores for athletes who will compete in events that is likely to deplete muscle glycogen stores. However, like most sports nutrition strategies, it is sport-specific and needs to be planned carefully. “Carb loading” does not mean you get free reign to eat all the cookies, doughnuts and sweets in sight, or stuff yourself with mac and cheese the night before a race. In the Macronutrients 101 series, we looked at what exactly carbohydrates are, why athletes need them, and how much should be consumed on a daily basis. Now, we will look at a popular but misunderstood method to alter carbohydrate intake to increase performance.

Consider the following things:

• If you try to carb-load in too short a time with too many fibre rich foods, like oats, whole grains, etc. it might lead to an upset stomach – not ideal for performance!
• This method may only lead to performance benefits in sports where muscle glycogen is likely to be depleted – usually sports that last for more than an hour, like endurance sports, intermittent sports like rugby/hockey/soccer, multiple-event sports like heptathlon, and so on. If your event is shorter than that, and you usually consume the recommended amount of carbohydrates on a daily basis, carbohydrate loading is unnecessary.
• There might be a temporary increase in body weight (glycogen) due to water retention. An increase of 1-2kg indicates that muscle glycogen stores are optimal. If making weight for a sport like wrestling is important, this should be considered before starting a protocol like carbohydrate loading as the water retention weight might impact weigh-ins. For sports like running, cycling or stop-and-go sports like rugby, soccer or tennis, this weight will be lost quite quickly during the event as your glycogen stores get depleted.
• It is best to experiment with any new nutrition strategy in training – never try something new on race day!
• You need to drink more water than you normally would during carb loading. 2,7g water is needed to store 1g of carbohydrate in your muscles and liver. Check your hydration status by looking at the colour of your urine – a pale colour indicates that you are adequately hydrated.

When should you start increasing carbohydrate intake?

A lot of athletes think that “carb loading” means eating a carbohydrate-rich meal the night before a race or event; however, true carb loading starts 2 – 3 days prior to the event. The more time you have before the event, the more low GI (higher in fibre) carbohydrate choices you can choose without upsetting your stomach. Low GI foods are generally preferable because they prevent excess blood glucose “spikes”, giving you more sustainable energy. For a complete list of low GI, intermediate GI and high GI foods, click here to visit the GI foundation’s website

Tips to modify your diet to increase carbohydrate intake 2-3 days before an event:

• Generally, if you are increasing your carbohydrate intake, you want to keep your protein intake consistent and lower your fat intake to prevent fat gain. Therefore, choose lower fat options for this time period – for example, lean cuts of meat, low fat/skim milk, etc.
• Choose snacks that are rich in carbohydrates, like fruit, crackers, sandwiches or smoothies.
• If you struggle to consume more carbohydrates than you usually do, supplement your diet with high carb, lower GI sports drinks before and after training, like 32GI Endure and Biogen Cytogen.
• Add an extra serving of starchy vegetables to your plate – for example, if you usually eat two slices of toast, try to eat three.
• Usually, your plate should be about ½ full of fruit and veg, ¼ full of lean proteins and ¼ of starchy carbohydrates. However, during the 2/3 days of carb loading, your plate should be filled with some extra carbohydrates – replace some non-starchy veg like lettuce, tomatoes and cucumber with veg that is higher in carbohydrate content, like beetroot, sweet potatoes or regular potatoes.

How much carbohydrate do you need to consume during this time period?

Depending on your training schedule, and how much you are tapering and resting before the event, as well as your normal daily carbohydrate intake, anything between 7 – 11g/kg can be considered “carbohydrate loading”. The uptake of glycogen into muscles can be highly individual, so if you need help to calculate the exact amount your body needs, I recommend seeing a sports dietitian in your area for more personalised advice.