|Sports nutrition and low GI energy foods are easy to find in supermarkets and in sports stores|
Energy for our body (Calories or kilojoules), is available in four forms:-
a) Carbohydrates (which contain 4 cal/17kJ per gram)
b) Proteins (which also contain 4 cal/17kJ per gram)
c) Fats (which contain 9 cal/37kJ per gram)****
d) Alcohol (which contain 7 cal/29kJ per gram)
****Fat is energy dense as it provides a lot of energy in a smaller amount of food.
The difference between each one is how it is processed when it enters the body and how quickly the energy is available for use.
Lets look at THE HUMBLE CARBOHYDRATE
• High muscle-glycogen concentration will allow you to train at optimal intensity and achieve better results
• Low muscle-glycogen concentration will lead to early fatigue, reducing the intensity of your training and this will be reflected in your race/performance results.
How much Carbohydrate should I eat?
|Whether you are recreational or professional, |
your diet will affect your performance
Once upon a time, carbohydrate recommendations were based on a percentage of your daily caloric needs and although sports nutritionists recommend that all regular exercisers and athletes consume a diet high in carbohydrate and low in fat the amount of carbohydrate consumed is based more on the level of activity of the individual.
So your daily carbohydrate intake will vary depending on your activity level.
General exercise – (up to 1 hr of daily exercise) 5-6g/kg body weight of carbohydrate per day.
Moderate exercise – (1-2 hrs of moderate to high intensity training) 6-8g/kg body weight
Endurance exercise (greater than 120 minutes of high intensity training) 9-10g/kg body weight
Extreme Exercise (greater than 4 hours of intense exercise eg: a cycling tour) 10+g/kg body weight
Training over 1 hour means you should have some carbohydrate intake DURING the exercise 30-60g per hour
KICK STARTING RECOVERY - During the 2 hour post-exercise period, consume 1g/kg body weight of moderate to high GI food.MOST IMPORTANT - But if you train twice a day, this is ESSENTIAL!
What does 30g of Carbohydrate look like?
2 slices of bread
1 average bread roll
3 weet bix
1.5 cups cooked lentils
600ml of Milk
2 tblsp of susteagen powder
2 medium apples
1 medium to large banana
1 cup of pasta
0.5 cups baked beans
0.75 cup of cooked rice
0.5 cup creamed rice
10 Jelly Beans
500ml sports drink
0.67 Power Bar
* Check labels on your foods and ensure you use low fat varieties where possible
The Glycaemic Index
Carbohydrates are all different and will be absorbed and used at different rates and the effect of other items in your body, such as fat may slow down the absorption of the carbohydrate even more. The glycaemic index was developed to describe the effects of foods on your blood sugar levels by how quickly the carbohydrate is absorbed from your small intestine into your bloodstream, and this is found to make a difference to training and recovery.
Foods with a low GI (glycaemic index) will provide a glucose response for longer and a high GI will provide more of a rapid energy. To find out more about Glycaemic Index, refer to the Glycaemic Index website which is written by the University of Sydney and provides a range of information about the glycemic index of foods and what it means to you.
The most important thing to remember is that choosing low GI foods should NOT be confused with low Carbohydrate foods, as an athlete, you want to keep your carbohydrate level high.
Considerations to be made on Carbohydrate Consumption
- Duration and Intensity of Exercise
Exercise lasting less than an hour
Provided you have enough glycogen stores and have eaten a meal with carbohydrate 2-4 hours before exercise, you should only require water and not require any further intake of carbohydrate. If you are racing though, you can delay fatigue by consuming carbohydrate during exercise to assist with the high intensity and delay fatigue.
Exercise over an hour
|Racing and high intensity training increases the requirements|
for carbohydrates and increases the need to
replenish the valuable muscle glycogen stores
|In cycling, the large muscles of the legs are working at a high intensity, |
especially during racing
If you fully deplete your glycogen stores, they can take anything up to a week to fully restore. Ask a marathon runner, when they feel recovered enough to take on another one.
High Carbohydrate diet, will assist with muscle -glycogen storage which helps with endurance and delays fatigue.
Read about GI index to understand why some foods are better for stabilising glucose and therefore energy levels than others.
High workload/intense efforts require additional carbohydrate
Don't forget to "top-up" carbohydrates during longer training sessions, during races.
RECOVER faster by replenishing your muscle-glycogen storage.
Protein will assist with recovery and endurance
Although I haven't mentioned it here, carbo-loading (later topic) can improve endurance capacity by up to 20%.....it is that muscle-glycogen level AGAIN!