“I did a marathon last weekend and I didn’t eat or drink anything,” a fellow dietitian and runner told me. I think my jaw dropped. Then she added with a laugh, “But I wouldn’t recommend doing what I did.”
Have you heard something like this before…or maybe said something like this? Or perhaps you’re new to running and haven’t given hydration for running much thought.
Even if you feel fine without water when running, that doesn’t mean it should be skipped.
In this article, I will explain why hydration is an essential aspect of running if you want to perform and feel your best during and after running. I will also give you some basic guidelines for hydration for running.
Why Does Hydration Matter for Running?
First of all, dehydration can negatively impact your performance. Being dehydrated by as little as 2-3% can contribute to greater fatigue and muscle cramps. If you get tired sooner, you won’t be able to hold your training or race pace, or hit those tough intervals during intense sessions. This could mean slower improvements and worse race times, or simply less enjoyable running for exercise.
Second, dehydration can contribute to GI issues such as nausea, pain, and intestinal permeability. Permeability (sometimes referred to as “leaky gut”) is something that can happen during endurance running at a fairly high intensity due to reduced blood flow to the intestines. This can allow toxins into the bloodstream and contribute to inflammation and discomfort.
It is estimated that as many as 90% of runners experience GI issues (bloating, belching, gas, abdominal pain, urge to poop, etc) during runs, so most likely you personally know how nausea, a side stitch, or runner’s diarrhea can seriously slow you down and take the fun out of running. Staying hydrated is one tool you can use to try to reduce GI problems.
Third, if you don’t hydrate well before, during and after workouts, you may experience more fatigue, headaches, or poor recovery after your runs.
Guidelines for Ideal Hydration for Running
While hydration for running should be personalized to your needs, length of run, and comfort, here are some general guidelines to use when planning your water and electrolyte intake.
- Before Your Run
Whether training or racing, you should be properly hydrated. Aim for about 16 oz of water within the two hours before your run if you can handle it without too much stomach sloshing. Even if you run early in the morning, try to drink at least an 8oz glass of water first. One way to know if you’re hydrated is to check the color of your pee. If it is amber or dark yellow, then you are dehydrated and need to drink more water. You might also consider adding some sodium (up to 500mg), electrolytes, or drinking a sports drink if you will be running for longer than an hour.
- During Your Run
For optimal hydration for running, consuming 1-2 cups of water per hour is recommended. However, this will need to be personalized to your digestive comfort and sweat rate, and you should drink to thirst. It can be hard to keep track of how much you’re drinking, so another way to think about this is to drink about 4-6 ounces every 15 to 20 minutes; Or, take 5 sips of water (which is approximately 1 ounce) every 20 minutes. This will help you to consume enough water to keep you hydrated during your run. You will need to practice drinking water when you run to learn how much you can tolerate, especially if you’re planning to race. Try increasing your intake slightly with each run until you find what keeps you hydrated and energized without causing stomach upset or cramps.
Generally, the longer and harder you run, the more water and sodium you’ll need. If you’re running for an hour or less, plain water should be fine. Beyond 60 minutes, you should consider adding sodium/electrolytes and carbohydrates to your water to keep you well-hydrated. At least 300-500 grams of sodium per hour should suffice, but some people may need more. For carbohydrates, 30-60 grams of carbohydrates per hour works well for most people, although you can train your gut to consume more if needed. This will not only provide the energy to keep going but it will help your cells to better absorb water.
- After Your Run
To enhance recovery and energy after a run, you will want to replenish any fluid lost, plus some. The best way to figure this out is to weigh yourself before and after your run. For every pound lost, consume 16-24 ounces. If your post-run weight is fairly close to your pre-run weight, then you’re probably consuming enough water and nutrition. Ideally, add some sodium or consume a sports drink to replace sodium lost in sweat during your run. You could also try using an electrolyte packet and put half into your water before your run and half after. This added sodium will help you to rehydrate more effectively, and you’ll probably find that you don’t feel so tired afterward and recover better.
Factors to Consider for Hydration for Running
The amount of water you drink during your run depends on different factors such as the intensity of training or racing, temperature, length of training, and sweat rate. Longer distances, hotter temperatures, and higher intensity will require more hydration. For instance, an easy zone 2 run in cool weather in the morning for 45-60 minutes won’t require much water or sodium compared to a 1.5-hour high-intensity interval session in mid-day heat or a half-marathon race. Sweat rate also plays a role – someone who sweats heavily will need more water and sodium than someone who barely breaks a sweat. Personal comfort is also essential. For example, if I try to drink two cups per hour, I will likely end up with a side stitch, especially in a race situation. So instead, I drink as much as I comfortably can. You will need to make it work for you, which comes with time and practice.
To Sum it Up
Hydration is crucial for running performance, recovery, GI comfort, and helps maintain a healthy body long-term.
- Before a run, drink 8-16 ounces of water. Include sodium if you’re dehydrated and/or running for several hours.
- During a run, drink to thirst, but aim for 1-2 cups per hour if possible. For runs under 60 minutes, plain water is fine. Over 60 minutes, include sodium and carbs.
- After a run, consume 16-24 ounces of water with some sodium for every pound lost.
Remember that hydration is very personalized, so it’s important to learn about your own body, sweat rate, and how you respond to water intake during exercise. By following these guidelines and figuring out what works best for you, you’ll be on your way to many successful runs! If you need more help personalizing these concepts for yourself, you can contact me for nutrition coaching.
References:
Costa, R. J. S., Snipe, R. M. J., Kitic, C. M., & Gibson, P. R. (2017). Systematic review: exercise-induced gastrointestinal syndrome-implications for health and intestinal disease. Alimentary pharmacology & therapeutics, 46(3), 246–265. https://doi.org/10.1111/apt.14157
Taylor, G., Leonard, A., Tang, J. C. Y., Dunn, R., Fraser, W. D., Virgilio, N., Prawitt, J., Stevenson, E., & Clifford, T. (2023). The effects of collagen peptides on exercise-induced gastrointestinal stress: a randomized, controlled trial. European journal of nutrition, 62(2), 1027–1039. https://doi.org/10.1007/s00394-022-03051-2
Tiller, N.B., Roberts, J.D., Beasley, L. et al. International Society of Sports Nutrition Position Stand: nutritional considerations for single-stage ultra-marathon training and racing. J Int Soc Sports Nutr 16, 50 (2019). https://doi.org/10.1186/s12970-019-0312-9
