AIS Sports Nutrition

Carbohydrate - The Facts

The term carbohydrate is synonymous with sports nutrition. The immediate impact of carbohydrate intake (or its absence) on daily training and competition performance has been widely researched and documented. Recent media attention has suggested low carbohydrate diets are beneficial for weight loss and other health benefits. In addition, different approaches to fuelling sports performance has become an item of discussion among scientists ( and the locker room) from time to time. It is no wonder many recreational and elite athletes remain unsure of the amount of carbohydrate they need to support their training and to optimise performance while achieving a weight and body composition that is appropriate for their sport.

Why is carbohydrate important?

Carbohydrate is a key fuel source for exercise, especially during prolonged continuous or high-intensity exercise. The body stores carbohydrate as glycogen in the muscles and liver, however its storage capacity is limited. When these carbohydrate stores are inadequate to meet the fuel needs of an athlete’s training program, the results include fatigue -, reduced ability to train hard, impaired competition performance, and a reduction in immune system function. For these reasons, athletes are encouraged to plan carbohydrate intake around key training sessions and over the whole day according to their carbohydrate requirements as an exercise fuel. 

How much carbohydrate do athletes need?

Carbohydrate requirements are dependent on the fuel needs of the athlete’s training and competition program. Exactly how much is required is dependant on the frequency, duration and intensity of the activity. Since activity levels change from day to day, carbohydrate intake should fluctuate to reflect this. On high activity days, carbohydrate intake should be increased to match the increase in activity. This will help to maximise the outcomes from the training sessions and promote recovery between sessions. Alternatively, on low or no training days, carbohydrate intake should be reduced to reflect the decreased training load. A clever way to adjust carbohydrate intake from day to day is to schedule carbohydrate-rich food choices at meals or snacks around the important training sessions. As the sessions increase in their carbohydrate demands, so should the athlete increase their carbohydrate intake before, during or after exercise. 

Not only does this strategy help the athlete to keep track of their total carbohydrate needs, but it ensures that the timing of the carbohydrate is best suited to fuel the session. 

The table on this page provides some general targets for daily carbohydrate intake goals across a range of activity levels. Each athlete should fine-tune their carbohydrate intake with individual consideration of total energy (kilojoule) needs, specific training demands, and feedback from training performance. Additional guidelines outline the specific ways in which carbohydrate intake can be timed to enhance carbohydrate availability for key sessions.

Which foods are good sources of carbohydrate? 

Many everyday foods and fluids contain carbohydrate, but have different features. For this reason, carbohydrate-containing foods and fluids are often divided into categories for comparison. Previously, carbohydrates were classified as either simple or complex, and more recently, the terms low and high glycemic index (GI) are being used (more on GI below). From a sports nutrition point of view, it is more helpful to classify carbohydrates as nutrient-dense, nutrient-poor or high-fat.

Category Description Examples Use for athletes
Nutrient-dense carbohydrate Foods and fluids that are rich sources of other nutrients including protein, vitamins, minerals, fibre and antioxidants in addition to carbohydrate Breads and cereals, grains (e.g. pasta, rice), fruit, starchy vegetables (e.g. potato, corn), legumes and sweetened low-fat dairy products Everyday food that should form the base of an athlete’s diet. Helps to meet other nutrient targets
Nutrient-poor carbohydrate Foods and fluids that contain carbohydrate but minimal or no other nutrients Soft drink, energy drinks, lollies, carbohydrate gels, sports drink and cordial Shouldn’t be a major part of the everyday diet but may provide a compact carbohydrate source around training
High-fat carbohydrate Foods that contain carbohydrate but are high in fat Pastries, cakes, chips (hot and crisps) and chocolate ‘Sometimes’ foods best not consumed around training sessions

See the carbohydrate ready reckoner for foods that each provide 50g carbohydrate

Daily Needs for Fuel and Recovery:


Situation Carbohydrate Targets
Light Low-intensity or skill-based activities 3–5 g per kg BM
Moderate Moderate exercise programme (~1 hr / day) 5-7 g per kg BM
High Endurance programme (i.e. moderate-to-high intensity exercise of 1-3 hr / day) 6-10 g per kg BM
Very High Extreme commitment (i.e. moderate-to-high intensity exercise of >4-5 hr / day) 8-12 g per kg BM

Acute Fuelling Strategies:


Situation Carbohydrate Targets
General fuelling up Preparation for events < 90 min exercise 7-12 g/kg per 24 hr as for daily fuel needs
Carbohydrate loading Preparation for events >90 min of sustained/intermittent exercise 36-48 hours of 10-12 g/kg BM per 24 hour
Pre-event fuelling Before exercise > 60 min 1-4 g/kg BM (consumed 1-4 hr pre-competition)

During brief exercise

During sustained high-intensity exercise

During endurance exercise including “stop and start” sports

During ultra-endurance exercise

<45 min

45-75 min

1-2.5 hours

2.5-3 hours

Not required

Small amounts including mouth rinse

30-60 g/hr

Up to 90 g/hr using multiple transportable carbohydrates (glucose:fructose mix)


Speedy refuelling <8 hr recovery between two fuel demanding sessions 1-1.2 g/kg BM every hour for first 4 hr then resume daily fuel needs

What about Glycaemic Index? 

Glycaemic Index (GI) is a ranking of how quickly carbohydrate foods raise blood glucose levels (BGLs) in the body following ingestion. High GI foods are rapidly digested and absorbed by the body and raise BGLs quickly. Low GI foods, on the other hand, are much slower to be digested and absorbed and result in more gradual rise in blood glucose levels. Refer to the official Glycemic Index website for more information (http://www.glycemicindex.com/).

In sport, it is important to consider immediate requirements and what a whole food or snack can provide (such as protein, vitamins and minerals) rather than looking at only one component of any food. For example, higher GI foods can be useful immediately after exercise to promote a faster recovery of muscle glycogen stores. Daily requirements, based on physique and performance goals should also be considered when making such food choices.

When is carbohydrate important?

An individual’s carbohydrate requirements before, during and after training or competition depend on a number of factors including: 

  • type, intensity, duration of exercise
  • frequency of exercise or time available for recovery between sessions
  • body composition goals
  • environmental conditions
  • training background 
  • performance goals for the session. 

While the recommendations provided above consider the overall carbohydrate needs over the day, it is also important to consider the timing of carbohydrate around training and competition.

Carbohydrate ingestion before exercise should assist in topping up blood glucose levels as well as glycogen stores in the muscle and liver. This is especially important if the competition or training is undertaken first thing in the morning or if the event is high intensity or will continue beyond 90 mins in duration. Refer to Carbohydrate Loading and Eating Before Exercise fact sheets for further information.

The replacement of carbohydrate during prolonged exercise can benefit sports performance, both through effects on the muscle (reducing/delaying the decline in exercise intensity with time) and the brain/central nervous system (reducing/delaying the decline in concentration and mental skills, as well as reducing/delaying the decline in pacing strategies with time). Using specific training sessions to practice consuming specific carbohydrate foods is also important if it is intended to be consumed during a competition.

Carbohydrate intake after exercise is essential for optimum recovery of glycogen stores. Often athletic performance is dependent upon the ability to recover from one session and do it all again in the next session. Incomplete or slow restoration of muscle glycogen stores between training sessions can lead to a reduced ability to train well and a general feeling of fatigue. In competition, it may also reduce subsequent performances where efforts are repeated within or across days (such as in a tournament, a swim or athletics meet, or a rowing regatta). Refer to the Recovery Nutrition fact sheet for more detailed information.

Food Portions Providing 50 g of Carbohydrate 

CEREAL

Wheat biscuit cereal (e.g. Weet Bix) 

60g (5 biscuits)

'Light' breakfast cereal (e.g. Cornflakes)

60 g (2 cups)

'Muesli' flake breakfast cereal

65 g (1-1.5 cups)

Toasted muesli

90 g (1 cup)

Porridge - made with milk

350 g (1.3 cups)

Porridge - made with water

550 g (2.5 cups)

Rolled oats

90 g (1 cup)

Bread

100 g (4 slices white or 3 thick wholegrain)

Bread rolls

110 g (1 large or 2 medium)

Pita and lebanese bread 

100 g (2 pita)

Chapati

150 g (2.5)

English muffin

120 g (2 full muffins)

Crumpet

2.5

Muesli bar

2.5

Rice cakes

6 thick or 10 thin

Crispbreads and dry biscuits

6 large or 15 small

Fruit filled biscuits

5

Plain sweet biscuits

8-10

Cream filled/chocolate biscuits

6

Cake style muffin

115 g (1 large or 2 medium)

Pancakes

150 g (2 medium)

Scones

125 g (3 medium)

Iced fruit bun

105 g (1.5)

Croissant

149 g (1.5 large or 2 medium)

Rice, boiled

180g (1 cup)

Pasta or noodles, boiled 

200 g (1.3 cups)

Canned spaghetti

440 g (large can)

FRUIT

Fruit crumble

1 cup

Fruit packed in heavy syrup

280 g (1.3 cups)

Fruit stewed/canned in light syrup

520 g (2 cups)

Fresh fruit salad

500 g (2.5 cups)

Bananas

2 medium-large

Large fruit (mango, pear, grapefruit etc.)

2-3

Medium fruit (orange, apple etc.)

3-4

Small fruit (nectarine, apricot etc.)

12

Grapes

350 g (2 cups)

Melon

1,000 g (6 cups)

Strawberries 

1,800 g (12 cups)

Sultanas and raisins

70 g (4 Tbsp)

Dried apricots

115 g (22 halves)

VEGETABLES

Potatoes

350 g (1 very large or 3 medium)

Sweet potato

350 g (2.5 cups)

Corn 

300 g (1.2 cups creamed corn or 2 cobs)

Green Beans

1,800 g (14 cups)

Baked beans

440 g (1 large can)

Lentils 

400 g (2 cups)

Soy beans and kidney beans

400 g (2 cups)

Tomato puree

1 litre (4 cups)

Pumpkin and peas

700 g (5 cups)

DAIRY PRODUCTS

Milk

1 litre

Flavoured milk

560 ml

Custard

300 g (1.3 cup or half 600 g carton)

'Diet' yoghurt and natural yoghurt

800 g (4 individual tubs)

Flavoured non-fat yoghurt

350 g (2 individual tubs)

Ice cream

250 g (10 Tbsp)

Fromage frais

400 g (2 tubs)

Rice pudding/creamed rice

300 g (1.5 cups)

SUGARS and CONFECTIONERY

Sugar

50 g

Jam

3 Tbsp

Syrups

4 Tbsp

Honey

3 Tbsp

Chocolate

80 g

Mars Bar and other 50-60 g bars

1.5 bars

Jubes and jelly babies

60 g

MIXED DISHES

Pizza

200 g (medium -1/4 thick or 1/3 thin)

Lasagne

400 g serve

Fried rice

200 g (1.3 cups)

DRINKS

Fruit juice - unsweetened

600 ml

Fruit juice - sweetened

500 ml

Cordial

800 ml

Soft drinks and flavoured mineral water

500 ml

Fruit smoothie

250-300 ml

SPORTS FOODS

Sports drink

700 ml

Carbohydrate loader supplement 

250 ml

Liquid meal supplement

250-300 ml

Sports bar

1-1.5 bars

Sports gels

2 sachets

Glucose polymer powder

60 g

(Source: Peak Performance: training and nutritional strategies for sport J. Hawley and L. Burke. Sydney: Allen & Unwin, 1998).

 Written by AIS Sports Nutrition, last updated Feb 2014. © Australian Sports Commission. www.ausport.gov.au/ais/nutrition 

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