Dr Alan Barclay
The winning edge: using the GI to maximise performance.
Optimising the amount and type of carbohydrate you consume before, during and after an event can provide you with that winning edge. For most forms of physical activity, our muscles preferred source of fuel is glucose. This is because the carbohydrate we eat or drink, which is not used immediately for energy, is stored mostly in our muscles and liver as glycogen. When our muscles need fuel, our bodies quickly break down this glycogen into glucose for energy. That’s why, for optimal physical performance, it’s vital to consume the right amount and type of carbohydrate before an event to maximise glycogen stores. You can also improve your performance in an endurance event or a carnival, by carefully choosing the amount and type of carbohydrate you consume during and after the event.
The night before a morning event Your evening meal the night before should contain more carbohydrate than normal to stock up your body’s glycogen stores. The carbohydrate should be low GI and the whole meal should be lower in fat, moderate in high quality protein and comfortable in quantity (don’t over eat or drink).
The morning of the event Make your breakfast a carbohydrate-based one that’s lower in fat and moderate in protein. Exactly what you eat depends on the time between breakfast and the start of your event. The following table provides a guide based on your start time. As with dinner, only eat a comfortable amount, otherwise you may regret it …
Event foods
During the event choose high GI carbohydrates that are easily digested and absorbed like:
- Gatorade or other isotonic sports drink
- Goo or other gel/liquid glucose supplement
- Jelly beans or other sugary lollies
- White bread with regular honey
- Scones with regular jam
Aim to eat 1–2 hours after an event and your food and fluid choices should be low GI. Your body needs to replenish its glycogen stores, and delaying this replenishment can lead to fatigue and underperformance. The following suggestions will provide you with 75g available carbohydrate:
- 5–6 slices of a low GI bread like Burgen or Tip Top 9 grain
- 2½ cups Sustain cereal with reduced fat milk
- 11 Ryvita biscuits
- 1½ cups cooked basmati rice
- 3½ cups 100% fruit juice
- Milo or Sustagen
For more information about the GI Symbol Program
Dr Alan W Barclay, PhD
Chief Scientific Officer
Glycemic Index Foundation (Ltd)
Phone: +61 (0)2 9785 1037
Mob: +61 (0)416 111 046
Fax: +61 (0)2 9785 1037
Email: alan.barclay@gisymbol.com
Website: www.gisymbol.com