Training the Gut
Friday, March 18, 2011 at 10:51AM Asker Jeukendrup is one of the world’s leading sports nutritionists and has made it his mission to translate hard science into practical applications. In his latest post, he talks how training your stomach to survive race day is as important as training the rest of your body.
The start of the season is always exciting. What a great start of the year: a few days in a warm climate, a beautiful and inspiring place to train. I am sure everyone who reads this is familiar with the sentiment: This year you are going to do everything perfect, train hard, have the perfect preparation. This year you will also finally work out the perfect nutrition plan.
Athletes pay a lot of attention to training. Often this is meticulously planned for an entire season, then athletes spend somewhere between 7 and 30 hours a week training. The compression socks are worn, some even apply ice baths to help the recovery process, all so they can do more training sooner. In the planning and preparation of a season, nutrition often gets relatively little attention. How many athletes train their nutritional intake for race day at a regular basis? Especially for Ironman triathletes and marathon runners this can prove to be crucial.
I see many marathon runners who enter their event, train like crazy, get to the start in great shape, then run, take on board gels and drinks as advised and as planned but then around mile 20 they realize that their stomach cannot handle that intake and they feel sick. Fullness, nausea and sometimes vomiting are the result. It probably would have been better for them to not take anything on board.
However, it would have been EVEN better if they has incorporated what I call nutritional training into their training. What this means is training your gut to handle the carbohydrate intake that is optimal for your race. The gut is an extremely trainable organ. You can train it just like you train your muscle and it will adapt according to the stresses it is exposed to. So if you expose it to a high carbohydrate load for example it will adapt its absorptive capacity and tolerance.
To achieve this, you need a high carbohydrate intake most of the week (which most endurance athletes seem to adopt anyway) and must practice your nutrition intake for race day. One session a week or so should be dedicated to nutritional training. In this (long) session the goal is to take on board the same amount of carbohydrate as you would during your event. For the advanced athlete the amounts should be increased even more as on race day the intensity will most likely be a bit higher making tolerance worse.
On the flip side, athletes who are avoiding carbohydrate during training or are trying to reduce their intake to reduce body weight will put themselves in a less favorable position. Their gut will not be adapted as well to a high carbohydrate intake. Also for those athletes, incorporating a nutritional training session per week would be helpful.
Some athletes worry about weight gain but that fear is unfounded. The energy expenditure during training is almost always well in excess of your intake. For many serious athletes an energy expenditure of 600-1000 kcal per hour is completely normal. A high carbohydrate intake would be 250 kcal and the maximum recommended would be around 360kcal. So you will always be in negative energy balance during training (unless the intensity is so low that carbohydrate intake is not required anyway).
There is plenty of evidence that in events longer than about 90 min carbohydrate intake works. In one of my future blogs I will give some clear recommendations on amounts and types of carbohydrates during an event but for now it is just important to incorporate nutritional training into your training. There is no need to do this much longer than 4 months before the event and there is no need to do this too often. In fact there may be reasons why you don’t want it too often. When taking large amounts of carbohydrate on board you may suppress fat metabolism and you would perhaps not train your fat burning as much. So different training sessions have different goals, and training sessions are supposed to give different training stimuli. One of those stimuli should be nutritional training: training the gut.
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Asker Jeukendrup is a registered sport and exercise nutritionist. He is also a Fellow of American College of Sports Medicine and European College of Sport Sciences and a member of the Nutrition Society, Physiological Society, American Physiological Society, the New York Academy of Sciences and the American Diabetic Association. Asker is the Editor-in-Chief for the European Journal of Sport Science, member of the Advisory Editorial Board of the Journal of Sports Sciences, and served on the editorial board of the International Journal of Sports Medicine and Medicine and Science in Sport and Exercise. Asker is also the author of several books including High Performance Cycling and a Textbook on Sports Nutrition in collaboration with Prof Michael Gleeson. You can visit his website here.
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Reader Comments (1)
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