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17 Jun 2011

Burning carbs
Hi Diet Doc,

There''s something I''ve been pondering about regarding carbohydrage consumption and exercise: Say for instance one consumes some form of carbohydrate (be it good or ''bad'', such as cereal, rusks, etc) late at night (between midnight and say 2am)... Is the energy provided by these carbohydrates available by the next morning (say between 7 and 10am) when one is doing cardiovascular exercise, such as running? I am a novice runner that runs about 60km a week and I find that I''m often hungry or craving carbs if I''m awake late at night. When I eat then, I feel a bit guilty just going to bed straigt after! So, I''m just wondering if those carbs actually serve some purpose the next day  whether this is almost a form of carbo loading??

Your guidance will be appreciated.

Thank you!
Answer 437 views

01 Jan 0001

Dear Curious
There are no 'good' or 'bad' carbohydrates, when it comes to running long distances. We do differentiate between carbs with a low glycaemic index (GI) and those with a high-GI. People who do a lots of sport like running those 60 km a week have a very high carb requirement, i.e. carbs should provide about 55% of their daily energy requirement. If you are an adult woman who is very active then you may need 2500 kcal or 10500 kJ of energy per day or even more depending on how much energy you use on a daily basis. If 55% of the energy should be provided by carbs, then this means that you require up to 340 gram of carbs a day. Ideally these carbs should be a mixture of low-GI and high-GI carbs. The low-GI carbs are used during the day spread over meals and snacks and the high-GI carbs are used before, during and after exercise to replenish your liver and muscle glycogen stores so that you don't get too tired, have plenty of energy and are ready to run again within a day. If you get carb cravings at night then this could be an indication that you are not eating sufficient carbs during the day and during exercise to meet your body's needs. You don't have to feel guilty if you eat carbs when you feel hungry, just balance the low- and high-GI carbs for maximum advantage. I have written many articles on the subject of diets for sportsmen and women. Click on 'DietnFood' at the top of this page and then on 'DietDoc's articles' and read the articles about sport diets. There is also info on the Fitness site. Click on 'Fitness' at the top of this page and then on 'Nutrition'. To read up about the GI, Click on 'Diet’nFood' and 'Weight loss' and 'The Glycaemic Index'.
Enjoy your running and stop feeling guilty
Best regards
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