Any discussion on marathon training, irrespective of exhaustive training, physically, with the best plan and trainer will not be complete without discussing the extremely important role of nutrition and diet.
Similar to the planned and periodized approach we take to physical training, it is very critical to plan and periodize nutrition throughout the training period and can in fact make or break your performance!
It will also decide your performance during the entire training period, your motivation levels and your health and fitness status (absence of sickness, fatigue, injuries and beyond that too). Fatigue, lack of ability to cope up with the daily activities, injuries, dehydration, nutritional deficiency syndromes are quite common complaints during the training period.
However, many of the people see marathon training as a weight-loss option and try out low fat diets, low carbohydrate (low-carb) diets and other fad diets, which can not only hamper final performance, but also cause long-term effects, which can sometimes be irreversible!
A good nutritional plan basically consists of three stages – the nutritional plan during the training period, couple of days before the final day, and that on the final day. An added emphasis on carbs is also a sign of a good nutritional plan. A high-carb diet is essential during this time, as decided by the sports nutritionist.
It is important to consult a nutrition expert to get the plan designed. This is because, when one says a high-carb diet is essential, the quality and type of carb is extremely important. Carbohydrates are of many types – simple, complex, high glycemic index, low glycemic index and the like. This is important because each of them has different absorption rates, and hence get absorbed at different speeds and quantities into the bloodstream.
A good nutritional plan basically consists of three stages – nutritional plan during training, few weeks before the final day, and that on the final day. Since nutritional requirements during the marathon training are higher than usual, it is important to eat the right kind of foods to avoid any additional weight gain which will increase the challenge on the body and hamper performance.
Carbohydrate-rich foods (Carbs) form the major component of diet during this time, followed by proteins and fats. Carbs are stored in muscles, liver and blood as glucose, and are easily available for providing energy. The rate at which the energy is released depends on a factor called as the ‘Glycemic index - GI’ (or another factor called glycemic load, closely related to glycemic index) of the carb consumed.
A low GI (usually complex carbohydrates) food gets into the system slowly, and thus ensures a slow and steady supply of energy. This helps to maintain stable and adequate blood glucose levels and ensure continuous supply of energy for longer distances. Simple carbohydrates usually have high GI and enter the system and get depleted fast, causing extreme variations in blood glucose levels, extreme highs followed by extreme lows. Some examples of low GI foods are whole grains like barley, legumes and pulses like kidney beans, soyabean, wheat bran and vegetables like green leafy vegetables, cauliflower etc.
Polished rice, bakery items like white bread, cookies, ready-to-eat cereals are all examples of high GI foods. Low GI foods also help avoid additional weight gain!
Therefore, usually complex carbohydrates form a major component in the nutritional plan (almost 65% - 70%), followed by proteins - for growth and repair, and fats – for proper functioning of the body systems, during the training.
The nutritional pattern changes as you approach the final day, with many techniques that are used to ensure stable energy supply for longer duration on your final day…