We have found very interesting article about carbohydrate intake during exercise. Because of the fact, that carbohydrates are the most effective fuel, there comes up a question – how to make them more effective, do not feel discomfort and reach the goal?
Read out, what Mark Funnell & Joseph Agu (Nutrition Consultants from the USA) says about it.
“Muscle glycogen (carbohydrate) stores are the primary fuel source during moderate to high-intensity endurance exercise. Although your glycogen stores are limited – approximately 400-500g in the muscles and 80-120g in the liver – they are sufficient to fuel endurance exercise lasting less than 90 minutes. When exercise exceeds 90 minutes, glycogen depletion can occur resulting in fatigue, a decrease in exercise intensity and performance. Therefore, consuming carbohydrate during endurance exercise can improve performance and training intensity by delivering more carbohydrate to the working muscles. However, drinking/eating carbohydrate during training or performance can cause stomach pain, cramping or distress, also known as gastro-intestinal (GI) discomfort. This raises the question, if you consume carbohydrate during training can you ‘train the gut’ to deliver more carbohydrate to the bloodstream and also decrease GI discomfort?
A study, by Cox and colleagues in 2010, assessed the effects of consuming carbohydrate during training on carbohydrate usage (exogenous carbohydrate oxidation) during exercise. Sixteen well-trained cyclists were split into either a high carbohydrate group (which consumed 1.5 grams of carbohydrate per kg of body weight during every hour of training) compared to a low carbohydrate group (which consumed no carbohydrate during training). The study found that training with carbohydrate increased ingested carbohydrate usage (exogenous carbohydrate oxidation) during exercise. The increase in ingested carbohydrate usage occurred in the absence of any obvious changes in the muscle, indicating it was most likely due to enhanced absorption of CHO into the bloodstream from the gut – suggesting that you can ‘train the gut’.
Summary and Recommendations:
- Consuming carbohydrate while training can increase its delivery and usage by the muscles and decrease GI discomfort.
- Start off slow with small amounts of fluid and carbohydrate. Gradually increasing the volume.
- Train your gut! Practice drinking/eating carbohydrate during training. This will reduce GI upset, bloating and fullness and improve gastric emptying.
- Think about the carbohydrate content of your drink. Drinks are usually 4-8% (Powerade and Gatorade). Higher concentrations may delay fluid availability and cause GI upset, so be cautious if using carbohydrate powders.
- Carbohydrate recommendations: 1-2 hours = 30 grams per hour (g/h), 2-3 hours = 60g/h and 3+ hours = 90g/h.”