During a lengthy run, how much water should I really be drinking?
Confession time: during my long training runs for the Chicago Marathon, I don’t drink anywhere close to the amount of water or sports drink that is recommended by the American College of Sports Medicine: three to eight ounces of a sports drink every 15 to 20 minutes. If I’m being really forthright, there are instances when I run more than six miles without taking in any liquids at all. (I know, I know, my running partner regularly calls me out on this and tries to get me to share her water and drink from every fountain we go by! However, in the spirit of full disclosure, I should mention that I very rarely get the symptoms of dehydration (cramps, dizziness, and exhaustion), and when I do, I immediately pull over and purchase some water. So, how terrible is it, exactly?
The response is: First things first, according to Antonucci, there is a significant distinction between the phrases “must drink H20” and “should drink H20.” “Could we run for ten miles without stopping for water and still finish the race without being dehydrated? In all likelihood, yes “she says. “But why would you do that? Why should I have to struggle?” (And why even put yourself in danger of dehydration and heat stroke, both of which are quite serious conditions?) According to Antonucci, having the appropriate proportions of water and sodium (yes, you do lose this vital electrolyte in your sweat as well!) helps you avoid hitting “the wall” in the middle of your run and could make you a more effective runner overall. In addition, if you are dehydrated, you will probably finish your run feeling exhausted and hungry, and you will continue to feel tired for the rest of the day.
Both of these things have happened to me, and I’ve always just chalked it up to “typical” side effects of going for a long run. It will be interesting to see whether adjusting my habits and staying hydrated when I’m running helps me feel less “run-gry” and tired in the middle of the day. However, now that I am persuaded that I ought to increase the amount of fluid that I consume, I am at a loss as to how to begin. What should I drink, how much of it, and how often should I do it?
MORE: Here Are 5 Ways You’re Not Hydrating Correctly
According to Antonucci, there is not a single answer that is appropriate for everyone that can be considered universally applicable. But what’s really interesting is how variable people’s requirements are depending on factors such as their body size (those with smaller bodies require less fluid), their perspiration rate (some of us just sweat more than others!), and the environment (obviously you need more fluid on steamier runs). However, here are some general guidelines for staying hydrated during runs that last longer than an hour:
Get a Jump on Things.
If you begin a run already dehydrated, there is no way to make up for lost time while you are out there. Again, there is no “correct” amount of water to drink before you run; but, according to Antonucci, you should make sure that your urine is a very light yellow before stepping out the door.
Begin with a Minimum Standard.
The amount of fluid you need to consume when running is directly proportional to the amount of perspiration you produce. According to Antonucci, the majority of people sweat between 24 and 32 ounces each hour while they exercise, and they should strive to replace at least 75 percent of that amount while they are running. This implies consuming between 18 and 24 ounces of water every hour while you are jogging. However, as was mentioned earlier, the rate at which individuals perspire varies, so…
Participate in a Sweat Test.
Antonucci says, only half in jest, “We should place a scale at the entrance to Central Park and allow people weigh themselves before and after their runs.” “We should put a scale at the entrance to Central Park and let people weigh themselves before and after their runs.” Finding out how much sweat you lose during a run can be determined by weighing oneself both before and after the run. This, in turn, allows you to determine if you are maintaining an acceptable level of hydration or whether the next time you go for a run you should sip more or less water. Although it’s unlikely that we’ll see scales installed in major parks any time soon, you may (and should!) weigh yourself before and after your next run to determine how much weight you’ve lost. According to Antonucci, if it’s more than two percent of your bodyweight, that’s a warning that the next time you run, you need to drink more water than you normally would.
Sodium Is Important, Too
If, after a run, you see that salt is caked on your face and arms, this is a sign that you lost a significant amount of the substance (remember, everyone loses it at various rates!). Therefore, the next time you exercise, you should consume extra sodium. “People are always shocked at how much better they feel when they add salt to their water or switch water for a sports drink,” adds Antonucci. “People are always amazed at how much better they feel when they add salt to their water.” You should either add some actual salt to your water (you may also add some honey for flavor and carbs), or make sure there is some sodium in whichever feeding option you choose to use. The average person loses between 800 and 1500 mg of sodium per hour from sweating. (A serving of Gatorade contains 110 milligrams, while a serving of Gatorade Endurance contains 200 milligrams.)
In a nutshell, the likelihood of you becoming dehydrated is significantly higher than the likelihood of you becoming overhydrated. In light of the fact that you will most likely experience symptoms of dehydration (such as dizziness, cramps, and so on) before you suffer any significant concerns (such as heat stroke), it is unquestionably a good idea for you to calculate your sweat weight and drink water while you are exercising.