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Best of Nutrition Advice - Summary of the Chat with PowerBar

2013-09-05

Nutrition expert Corinne Mäder gave tips for optimal nutrition throughout the whole 42.195-kilometer course
© Powerbar

On our Facebook page, BMW BERLIN MARATHON runners bombarded our PowerBar nutrition expert Corinne Mäder with questions. Here is a summary of the best questions and answers together with tips for optimal nutrition throughout the whole 42.195-kilometer course.

 How many gels should I consume during the marathon and when?

That depends on the individual and you should definitely try and figure out in advance during your training. As a rule of thumb and depending on individual tolerance, during a marathon we recommend up to approximately 60g of carbohydrates per hour (e.g. one Powergel every 30 minutes). However, in addition to that, you should not forget about your hydration strategy.

 "By the 30-kilometre mark or earlier I'm usually running on empty" - how can this be avoided?

During training you should simulate a competitive situation to get a feeling for WHAT kind of food and fluid suits you best, WHEN and in what quantities. This will help you avoid nasty surprises and unpleasant symptoms caused by a drop in blood sugar levels. It is also advisable to eat sufficient quantities of carbohydrate (e.g. pasta, bread, dried fruits) in the days leading up to the marathon, so that the energy stores in the muscles (glycogen stores) are well loaded. In addition, for an optimum preparation, you should make clever nutrition choices in the final hours before the competition.

 What do you recommend shortly before the start?

Small, carbohydrate-rich snacks such as energy bars or a ripe banana up to one hour before the start are a good choice. If you are very nervous and tend to suffer from pre-competition jitters, liquid carbohydrate preparations (e.g. gels dissolved in water) are usually better tolerated than solid food.

What are the considerations regarding nutrition if you are running a marathon for the first time?

The key element with regard to nutrition is not to experiment on the day of the race itself! We have put together a basic nutrition advice leaflet with the most important sports nutrition tips especially for runners. This leaflet can be downloaded free of charge from the following link:

http://www.powerbar.co.uk/download/pdf/nutrition_coaches/Nutrition_Coach_Running_engl_web_2013.pdf

 How long after consuming a gel does it take for the effect to set in?

There are a number of important factors involved: an initial effect occurs as soon as the carbohydrates come into sufficient contact with the mucous membranes in the mouth. Oxidation rate of ingested carbohydrates (e.g. glucose) seems to be about 1g per minute - In simple terms the oxidation provides then energy required for the muscles to work. Glucose, or maltodextrine as it is  contained in the Powergels, are both sources of carbohydrate which enter the bloodstream rapidly and whose effects are therefore quickly felt. In addition, the gels contain energy in the form of fructose. With this special combination of carbohydrate sources you can use even more energy per time unit as compared to glucose or maltodextrine alone.

 What about carb-loading? How exactly does this work?

Carb-loading is a tried-and-tested strategy, a special technique that consists in tapering your training one or more days before a race while increasing your intake of carbohydrates. Done correctly, the net result is an increase in the glycogen stores in your muscles. In recent years the methods have changed greatly. Nowadays the following method is recommended: In the three days before the marathon ensure that you eat a carbohydrate-rich diet, low in fat and fibres and simultaneously reduce your training. Carbohydrate-rich foods such as pasta, rice, mashed potato, dried fruit, fruit smoothies are ideal during this "carb-loading phase". Practical tips include the following: At meal times, have an additional helping  of rice or pasta, and instead of low-calorie soft fruit eat a banana for dessert and an energy bar or some raisins as snack. However, it is important that you try out this strategy during the training phase before a long and intensive run.  This is because effective carb-loading also means you store additional fluid in the body (because carbohydrate is stored with water in the glycogen stores) meaning that your body weight increases and you have more to carry round. It is therefore important that you try this sports nutrition strategy in advance so that you know how it affects your performance. Carb-loading strategies which result in a glycogen supercompensation can certainly improve endurance performance such as a marathon run.

 Do the stores have to be depleted beforehand?

Not in the “extreme” form that this used to be done in the past. The disadvantage with such radical strategies is that they place a strain on the immune system, increasing the risk of infections and colds. Today we now know that carb-loading also works very well with less radical methods. An effective and pretty easy strategy to maximize your glycogen stores is to  increase your intake of carbohydrate and simultaneously significantly reduce your training (stick to easy, short work-outs) in the three days leading up to the marathon.

 What is the ideal drink immediately before a marathon?

The general recommendation is to drink roughly 5 to 7ml of fluid per kilogram of body weight 3 to 4 hours before the start. In the last hour prior to the marathon approximately 200 to 300ml of fluid is usually ideal. Any drink is suitable here that the individual tolerates well (sports drinks, sweet tea, water, etc.). Some athletes also like drinks containing caffeine, because caffeine can support performance and endurance athletes consider it a "mental booster". However you must be able to tolerate caffeine.

Does it matter how many sports drinks you consume or does their effect kick in after just one mouthful?

Research shows that there is a small initial effect as soon as there is contact with carbohydrates in the mouth (e.g. when a sports drink is consumed): Certain, activated receptors in the mouth send positive signals to the brain. This stimulates the central nervous system in the brain, which can bring about a performance-enhancing effect. This is on condition that the "swig" is held in the mouth for several seconds (as if it were a mouth wash). However this effect is of course too negligible for longer exercise periods because the muscles also need energy. Once the glycogen stores have been used up, exercising at maximum intensity cannot be continued. For this reason the body should be continuously supplied with sufficient carbohydrates during long endurance periods. Besides providing carbohydrates, sports drinks are of course also a source of liquid, a single "swig" will therefore not be enough to provide enough fluid during a marathon or to compensate for a lack of fluid (dehydration is a frequent cause of exhaustion in endurance athletes).