If you're a long-distance runner, you'll know how important it is to stay hydrated to avoid wearing yourself out, energy slumps, or what we all know as bonking. But how do you know if you're properly hydrated? When they train, most women runners go by the most basic cues: feeling thirsty or hot. In fact, we usually don't drink during training and wait until we're done to rehydrate. But that's not the right approach. Hydration, like taking supplements during races, has to be practiced and planned ahead to make sure you absorb fluids properly and keep your energy levels at their best.
The best approach is to set up a personalized hydration plan, since every runner has her own traits and needs, which vary depending on the type of race and the time of year. Still, the goal of any hydration plan is the same: to replace the fluids we lose through sweating and breathing.
But which variables should you keep track of to manage your hydration? Here are a few simple guidelines:
1.- Monitor your body weight: Your morning weight (before breakfast) is the most reliable one to use as a reference and for comparisons. Keep in mind the fluctuations that happen depending on the time of year and where you are in your hormonal cycle. For the latter, there are some pretty useful phone apps where you can check every day where you are in your menstrual cycle and log how you feel and how much you weigh.
2.- Check the color of your urine: The color and volume of your urine say a lot about how hydrated you are. If your urine is pale and plentiful before a race, it's a sign you're starting off well hydrated. If, on the other hand, it's dark and scant, it means you're slightly dehydrated and it would be a good idea to drink a bit more than usual before you start running.
3.- Finally, weigh yourself before and after your workouts: Use your long runs or higher-volume sessions to see how your weight changes. If you sweat a lot, you'll probably lose quite a bit of weight during races and run the risk of getting dehydrated. If you don't sweat much, then you should be careful not to drink too much.
Once you've tracked these variables over a representative period of time, apply this formula:
Weight lost (KG)= Weight before training (KG) – Weight after training (KG) + Fluid taken in during training (KG)
The weight you lose according to the formula is the amount of fluid you need to drink to make sure you're properly hydrated. If you drink more than that, you'll become overhydrated, which isn't a good idea. You should never gain weight while you run. On the other hand, slight dehydration isn't a cause for concern either: the limit is not losing more than 2% of the weight you had before you started, which works out to 1 or 2 kg at most.
It's important to do these exercises and keep repeating them throughout the season. That way, when race day comes, you'll have the confidence and experience to know when and how much to drink.