Why you don’t need to hydrate on short runs

The internet is full of heated exchanges about how and when to hydrate on runs of 45 minutes or less. But it turns out that as long as you start hydrated and are drinking during the recovery period, you probably don’t have to worry much about it.

Some thirst studies have shown that once you are dehydrated, drinking water gives you an exaggerated sense of how hydrated you are. This tends to give credence to the notion that you should follow a fluid intake schedule, of which there are many online. The American Council of Exercise recommends drinking 17 to 20 ounces of water two hours before exercise, and then seven to 10 ounces of fluid every 10 to 20 minutes during exercise. That’s a lot of water to drink in an hour’s run and enough to cause some serious discomfort from all that liquid sloshing around in a runner’s tummy.

In an interview with Canadian Running, sports expert and author Alex Hutchinson once commented that “During training, I personally almost never drink in runs up to about two hours. That changes on a hot summer day or doing intervals. I don’t mind feeling a bit thirsty, and I’m in tune enough with my body to recognize if I’m getting more dehydrated than usual. There’s a little bit of evidence that allowing yourself to get a bit dehydrated during training can trigger bigger fitness adaptations. That said, I’m not out there deliberately dehydrating myself–it’s what’s called “permissive dehydration.” I drink if I’m thirsty, but I don’t make a point of drinking during training. And I’m careful to make sure to drink before and after training, so that I’m not chronically dehydrated.”

Anecdotally, several runners in recent online discussions stated that, for them, during efforts up to an hour or so in length, drinking before exercise is more important than bringing water and drinking mid-run. Studies of hydration before exercise support the idea that going into your run hydrated may indeed be more important than drinking during the run. In any case, for short runs, if you start your run hydrated and drink during your recovery, you should have no worries about dehydration.