Fluids and You
Well, it’s Australian Open time and that means watching the top men and women players in the world playing tennis down under in Melbourne, Australia. With the south Pacific being on the other side of the globe from us, they are now experiencing summer, which can be notoriously hot in Australia. While we’re still in the process of thawing out here in the US and other places, proper hydration while playing tennis or other activities may not have the front of mind awareness that it does in the blistering summer heat. Even when the sun is not beating down on us, we need the proper amount of fluids in our body to maintain optimal performance, and now is a good a time as any to start developing proper hydration habits in preparation for the hot weather to come. Our focus today will be on what proper hydration is, why it’s important, and how to do it.
Body Composition
The average human adult’s body is composed of 60% fluid, and these body fluids are essential for proper day to day function and health. You may have heard that you need to drink up to eight eight-ounce glasses of water daily. That’s 64 ounces, or half a gallon, and while that may seem like a lot, when we become active that amount is not near sufficient to replenish our fluid levels. Let’s take a look at what the body does with water and why it cannot function without it.
Bodily Fluid – Content and Role
The human brain is 75% water, blood plasma is 92% water, the bones are22% water, and our muscles are 75% water. There is fluid constantly flowing across the cells of our bodies, delivering electrolytes, proteins, and amino acids that are crucial for cellular health. Waste gases such as carbon-dioxide and nitrogen are eliminated, and the filtering and delivery systems are also made effective through the body’s internal irrigation system. Internal fluid movement also serves to regulate our internal temperature, without which we could not function properly on a daily basis. The human body gains and loses approximately two and a half quarts of fluid daily, through the intake of food and beverages and the expelling of body fluids through the bowels, lungs and skin. The body’s evaporative cooling mechanism serves to maintain the narrow range of internal temperature necessary for normal operation, and it is vital that we maintain a steady intake of fluids so that our machine doesn’t overheat. We can lose up to a quart an hour on a hot day with even moderate activity, and if not replaced that loss can have adverse effects on our body’s performance and health.
Drink Early and Often
A critical element that is often overlooked when we think about hydrating is pre-hydration, which is simply drinking before you exercise. When you go on a long road trip, one of the first things you do is to fill your car up with gas, right? How often do you just hop in without looking at the fuel gauge? Never right? We always want to fill up before we head out on the road, and the court too. It is often recommended that we drink 16-32 ounces within the hour before exercise, depending on the expected intensity level. Professional athletes often will begin hydrating the night prior to a big game day, consuming a mix of electrolyte drink and water to ensure their bodies have a sufficient level of fluid. Heavy exertion or a long day on the court can lead to up to 5 to 8 pounds of body weight from fluids! It’s important to drink a 6-8 ounces of water every 15 minutes of exercise, as well as incorporating an a few ounces of an electrolyte drink during that exercise as well. The minerals in the electrolyte drink not only replaces those lost due to exertion, but the sodium encourages the continued consumption of more water.
After your exercise period, it is equally important to keep drinking fluids to ensure you replenish the fluids and minerals lost. Electrolyte beverages can greatly help in replacing these minerals, and should be incorporated in proper rehydration. Simply using water for or other beverages lacking in electrolytes in a short period of time can cause dilution of the blood and other fluids, causing increased urination and the further loss of fluids. This does not mean that we should discount water after exercise, but after prolonged periods of exercise where levels of electrolytes have been severely depleted, an electrolyte and mineral containing fluid should be incorporated, especially when rapid rehydration is called for.
Hopefully this has brought to light how important drinking fluids before, during, and after exercise is. Make sure you are aware of your hydration levels so that you can have a nice, long trip on the tennis court!
