What is the relationship between the glycemic index and running? There are times when eating low GI foods is better and vice versa. For best results, the athlete needs to know which food has what index and when to consume it.
Glycemic index and running
A low glycemic index means a smaller rise in blood sugar levels. Glucose has the highest glycemic index (100). According to the glycemic index, food can be divided into 3 groups:
- Low GI foods – up to 55
- Food with medium GI – from 55 to 70
- Foods with a high GI – from 70 to 100
Carbohydrates that we eat in the form of food are stored in the muscles and liver in the form of glycogen. A small amount of glucose circulates through the bloodstream. When you run at high intensity, the main fuel is glycogen from the blood and muscles. The body can also use fat, but at lower running intensities. The higher your glycogen stores, the longer you will be able to run before fatigue sets in. Maintaining these stocks is the key to a quality training program.
Benefits of low glycemic foods
Low GI foods are digested slowly and remain in the small intestine for a long time, hours after ingestion. The good sides are the slow and continuous release of glucose, which also occurs during physical activity.
With low GI foods, blood sugar levels are maintained stable, while consuming high GI foods, glucose is released too quickly, resulting in a large increase in blood sugar.
The best food before running
It is best to consume food that has a low glycemic index 2 hours before the competition or training. That time is enough for the stomach to digest that food. It is best to choose such foods that will not cause bloating and cramps, which is the case with fibrous foods. It is enough to consume 1 g of carbohydrates for every kilogram of body weight, 2 hours before running.
Examples of low-glycemic food for runners weighing about 50 kg:
- Oatmeal: 600g (two and a half cups) GI = 42 or
- Milk, chocolate: 250ml GI = 40 or
- Apples: 3 small / medium GI = 38 or
- Wholemeal bread with cereals and honey: 3 slices GI = 31.
The best food while running
Let your goal be 30g of carbohydrates and half a liter of water per hour.
Examples of foods suitable for this:
- Sports drinks: Isostar, Powerade, Gatorade, etc. 500-600ml or
- 30-35g jelly candies, pez, menthos, etc. (without sweeteners) + half a liter of water per hour or
- sandwich with honey + half a liter of water per hour.
The best food after running
Muscles are most sensitive the first hour after running because try to consume high-glycemic foods to regain lost glucose by then. Your goal is to consume 1-1.5g of carbohydrates per kilogram of body weight every 2-3 hours after the race. The day after, you can return to a normal diet. If it was a marathon, the recommendation is 10 g of carbohydrates per kilogram within 24 hours after the race. Avoid alcohol.
Examples of food after running suitable for athletes who weigh 50kg:
- Wholemeal bread with cereals: 3 slices spread with honey GI = 80 or
- Expanded rice – one and a half cups + 175ml of low-fat milk GI = 89 or
- 30-35gr candy GI = 80 or
- Sports drink 800ml G = 75.
The needs of long-distance runners and ordinary people are not equal. An ordinary person needs 240 g of carbohydrates per day but (semi) marathoners need 500-800 g of carbohydrates per day. This amount of carbohydrates is needed to avoid the situation of monitoring glycogen stores in the early stages of the race.
Athletes therefore choose more foods with a low GI than vice versa and thus remain less hungry, and sugar levels remain stable. For breakfast, they mostly choose cereals that have a high GI.