One of the first recommendations of hydration for marathon runners appeared in a book published at the beginning of the last century (J.E. Sullivan, 1909). It said: "do not fall into the habit of eating or drinking during the race, some runners do but there is no benefit." BIG MISTAKE! But even more amazing is that a hundred years later, and despite all the research that has been done in this area and all available information that demonstrates the benefits of staying hydrated during races and the progressive effect of dehydration, some athletes do not consume a drop of liquid during their training, nor when competing.
Through personal experiences, other runners, nutritional counseling and research, we can now review certain concepts and beliefs that we hope will help these “dehydrated runners” understand the importance of consuming liquids during races and making an effort to overcome any difficulty to hydrate .
Now, as bad as it is to get dehydrated, it’s just as bad to over-hydrate!
Hydrate, but don’t drown
While proper hydration is an important strategy to achieve good performance during a race, it is also necessary to avoid the other extreme; excessive hydration. This is especially important for light-weight runners who don’t sweat a lot and who can’t replenish large volumes of fluid (a conduct described as dipsomanía or “water intoxication”).
This can lead to a condition called hyponatremia, which, despite being much less common than dehydration, also can be life threatening. One of the most practical and effective ways to prevent this situation is to check your weight before and after running to make sure to avoid gaining weight during exercise as a result of excessive fluid intake.
Therefore, having a good hydration plan is possibly one of the best steps in nutritional care you can take to ensure the speed of your race.
Weigh yourself before and after training. This is one of the best tools to calculate how much fluid you need during exercise. If you lose 1 kg weight in one hour of running, that is equivalent to the loss of 1 liter of sweat. Therefore, it’s best to have many smaller doses of liquid during a run in order to drink a volume equivalent to that loss. Here you also have to consider weather factors as it’s not the same to run in 10C° as it is in 30C°.
During long runs of more than 2 hours, there may be an estimation error between 5% and 15%, as to the relationship between weight loss and sweat produced. Take this into account for long workouts.
Sports drinks provide significant benefits for hydration during races:
-They are flavorful and contain sodium which encourages a more complete fluid intake during exercise;
- They also contain carbohydrates which provide energy to the muscles during the race and this can allow you to run faster for longer period of time. In addition, those carbohydrates help you recover after the race;
- Finally, electrolytes, like sodium and potassium, help replenish losses produced by sweating.
Perhaps most important: start drinking before you get thirsty, because when it happens, you are probably already dehydrated. Moreover, as can be difficult to drink during the race, start drinking early is a good strategy.