The Importance of Hydration for Athletes


Coffee has water in it right?!  At least that’s what I tell myself when the sun is coming up in the morning.  As a marathon runner and physical therapist with an undergraduate degree in nutritional sciences, you would think I would be excellent about being properly hydrated.  The truth is I get frequently scolded by my coworkers for my lack of water consumption.  So maybe it’s a little ironic that I chose to discuss hydration in athletes, but the heat of the summer is here and high school sports and fall marathon training will be starting soon if they haven’t already.

While hydration seems like an obvious topic, not everyone realizes just how much proper fluid intake can affect an athlete, especially in the hot summer months. Hydration status during both training and big events can affect both mental and physical performance. A deficit of 2-3% of your total body weight in fluid has been known to result in a significant decrease in performance. Your body utilizes water to dissipate heat and prevent heat related illnesses, in addition to providing the muscles with the appropriate fuel to perform optimally. Maybe I have found the reason why I can’t seem to get anywhere close to a Boston Qualifying Marathon time.

Determining how much fluid to drink before, during, and after a training session or event is different depending on the person, activity, weather, and duration. Here are some general guidelines to follow to ensure proper hydration.

First, start by determining your hydration status by doing a ‘sweat test.’ A sweat test is done by weighing yourself without clothes both before and after exercise.  If you lose over 2% of your body weight, you are most likely in a dehydrated state.  If you are in a dehydrated state, typically drinking 2 cups of fluid for every 1 pound of body weight lost will help replenish your bodies stores.

In addition to the sweat test, you can also monitor your hydration status through urine color. The lighter the color throughout the day, the better hydrated you are. The darker the color, the more likely you need to grab that water bottle. Personally, I find that urine color is a little more accurate for me. As a smaller person I am typically not losing over 2% of my body weight after exercise but I can almost guarantee I am dehydrated more often than not.

While the numbers will vary depending on the athlete, the typical recommendation is drinking 16-20 ounces of water 2 hours prior to exercise. This is followed by 8-12 ounces 15 minutes before exercise and 3-8 ounces every 15-20 minutes during exercise.

If you are participating in a practice, training session, or event that is longer than 60 minutes, it is also important to drink a rehydration or sports beverage containing electrolytes (sodium, potassium, magnesium) in order to replenish the bodies lost fluids. This is especially important for long distance runners, as you can lose 1 to 3 grams of sodium per hour in your sweat. Now this is something I can hop on board with. My go-to rehydration drink is the Nuun tablets you just drop in water.  Typically if your exercise is less than 60 minutes, you will be able to replenish the electrolytes at your next healthy meal.

Because you body uses water to dissipate heat, it may also be beneficial to pour water over your head on hot summer days to keep your core temperature down.

Planning your hydration routine can seem rather trivial when considering all other aspects of training, but it is also one of the most important for optimal performance.  Overall, just simply drinking water throughout the day is going to help you go into your exercise, training sessions, and events properly hydrated.  Now I suppose I should go switch out this coffee for water…

If you are in need of pre or post surgical care, general re-conditioning, or help returning to sport/daily activities in the wake of an injury, schedule your appointment at one of our 11 Greater St. Louis area locations or via a Telehealth injury screening.

About the Author: Sam Bixby, PT, DPT, Astym Cert. grew up playing soccer and other sports. Upon graduation from Mizzou, she pursued her passion and received her Doctorate in Physical Therapy from Washington University in St. Louis in 2016. This has become a perfect career fit for Sam because of her fascination with human movement and how small breakdowns in movement can result in injury. She is a runner and can be found pounding the pavement in her spare time. She recently completed the grueling Big Sur Marathon in California.

To schedule an appointment with Sam or any of our expert physical therapists, request an appointment online today.