Updated 22 May 2013

The lowdown on carbo-loading

What can I eat to improve my performance? This is the question foremost in every Argus Cycle Tour participant's mind – and the answer: enough carbohydrates.


Few people realise that carbohydrate is the best-proven performance-enhancing substance – and it’s legal!

How does it work?

Carbohydrates are the main fuel source during hard training and racing. Fat is also a fuel source, but is only utilised at low intensities. At race pace, you predominantly use carbohydrate as fuel as it yields energy at a much faster rate than fat.

Unfortunately, unlike fat, your body can only store a small amount of carbohydrate in your liver and muscles – these limited stores can become depleted within ~90 min. of hard exercise, and as soon as these stores start running low, fatigue sets in (known as “hitting the wall”).

Therefore, by replacing your carbohydrate stores on a daily basis, especially during/after training and racing, you can maintain and/or spare your bodily carbohydrate stores, thereby delaying fatigue and improving your performance.

What should your training diet look like?

Carbohydrates should form the bulk of your meals/snacks to ensure refuelling of your carbohydrate stores on a daily basis:

  • e.g. bread/ pasta/ rice/ couscous/ potato/ vegetables/ fruit/ low-fat milk/ yoghurt or drinking yoghurt; add some concentrated carbohydrates to help boost your carbohydrate intake for optimal carbo-loading, e.g. jam/ syrup/ honey/ energy drinks/ cooldrinks (avoid caffeine & alcohol as they increase urine production = dehydrate you)/ jelly tots/ jelly babies/ marshmallows/ fruit juice.
    People who do not like the sweetness of these concentrated carbohydrates, or simply struggle to eat enough carbohydrates, can include “plain or neutral” glucose polymer powder (Refuel, Fastfuel) to their meals and/or drinks which will also help to boost their carbohydrate intake.
  • Drink plenty of fluids leading up to the race. The colour of your urine should always be light/pale yellow.

Optimise your training capacity

A sufficient amount of carbohydrates during training is as crucial to your overall performance as is sufficient carbohydrates during racing.

Concentrated carbohydrates (high-GI foods) are the food items of choice during and/or immediately after training or races as it is easy to eat (not very filling) and provide energy at a fast rate. It can be in liquid or solid form, depending on individual preference and comfort. Most people find drinking easier than eating during exercise. In this way, you can meet both your energy and fluid demands at the same time.

During a long race, you might feel hungry, then, eating solid forms of carbohydrates is fine – as long as they are easily digestible like potatoes (with a little bit of salt if you like), bananas etc. And don’t forget to still keep on drinking. Remember to practise what you’re going to eat/drink during the Argus beforehand, for example during long cycling sessions and/or minor races.

Exercise and competition

During exercise and competition, one should aim for a carbohydrate intake of 30-60g per hour; and 400-600ml fluid per hour of hard training or competition, depending on body size, pace, weather conditions and most importantly, what you feel comfortable with.

Refuel your carbohydrate stores as soon as possible after exercise / racing. ~1-2 x 50g carbohydrate portions should be ingested within 2 hours post-exercise for optimal recovery. If you don’t feel hungry at the time, then drink your carbohydrate energy drink, followed by a carbohydrate-rich meal or snack as soon as possible thereafter.

An additional benefit of taking a sufficient amount of carbohydrate before, during and after hard training and racing, is that it helps to give your immune system a boost and decreases your risk of infections.

The following portions each provide ~50g of carbohydrate:

  • 500ml Refuel / FastFuel / Soft drink
  • 800ml Isostar / Game
  • 750ml Energade
  • 650ml Powerade
  • 1 jam or banana sandwich/roll
  • 3 medium potatoes
  • 9 jelly babies
  • 3 pieces of fruit
  • 3 ½ tablespoons of raisins

What about protein?

The main function of protein for an athlete is to help build and repair damaged muscle. Active people do need more protein than sedentary people, but there is a cut-off limit beyond which more protein doesn’t have any extra benefit!

Most people (active or inactive) eat much more protein than they need. Only a very small percentage of athletes might need to use a protein supplement, e.g. those with a poor appetite, athletes on energy-restricted diets, or strict vegetarians.

Exciting new research show that adding a small amount of protein to your post-exercise recovery snack will increase the rate of muscle repair, and enhance the rate of carbohydrate refuelling. In general, you will have a faster recovery.

Examples of post-exercise snacks providing 50g carbohydrates + ~10g protein:

  • 300ml low-fat sweetened yoghurt or drinking yoghurt
  • chicken in pita bread
  • 15g biltong + 500-1000ml sports drink
  • cereal + low-fat milk
  • 200ml low-fat yoghurt + low-fat Granola or Nutrigrain or Safari fruit bar
  • 250-300ml liquid meal supplement, eg. Sustagen Sport, Build-Up
  • 250-350ml low-fat milkshake.

Lastly, while eating sufficient amounts of carbohydrate and protein, aim to keep your fat intake low (note: not completely fat free). A low fat intake, combined with a balanced diet and regular exercise, helps to keep your body fat down. Excess body fat is detrimental to your health, as well as your performance as it’s a dead weight that slows you down, tires you out much quicker and increases your risk of injuries.

REMEMBER: starving yourself is not conducive to successful weight loss or performance.

- (Written by Amanda Claassen, registered dietician (SA), specialising in sports nutrition)

(Photo of woman eating pasta from Shutterstock)

Read more:

Carbo facts for sports fanatics
Protein vs. carbs: the great debate


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