Fluid Facts: Why?

Hey Team!

I’ve got a couple more posts to round out my “Fluid Facts” theme….I’ve talked about the “who” “what” “where” and “when”, which brings us to “Why?”

Why do you need to think about fluid intake for exercise? Water plays a lot of roles in our bodies. It regulates our body temperature. It lubricates our joints (which is why water is so important for preventing joint pain). All of the metabolic functions in our bodies require fluid. It is what lets things move around from place to place in our bodies.

Our bloodstream is one of our bodies’ main transportation networks and we need water to keep that system flowing. It’s an odd analogy, but our bodies are sort of like the city of Venice, with the waterways representing our bloodstream. The term “dehydration” refers to having too little fluid in our blood, which can make the blood “thicker” and therefore makes the heart work harder to pump the blood through the body. What would happen if the water in the canals of Venice started to dry up? When the transportation system is stressed and things can’t be transported efficiently, the entire city would slow. It’s sort of the same when we get dehydrated: when oxygen and nutrients are not moving as efficiently through the bloodstream, our cognitive and athletic performance slows.

When we get dehydrated, our ability to cool our body also diminishes, putting us at risk for heatstroke. Dehydration also makes our muscles fatigue quicker. Because fluid helps keep our joints lubricated, join pain is another risk from dehydration.

Why do we also need to think specifically about sports drinks on longer rides? The electrolytes in those beverages replace the electrolytes we lose in our sweat. A normal balance of electrolytes in our bodies is essential. Sodium and potassium are the most commonly discussed electrolytes. You may remember from your high school chemistry class that electrolytes are basically substances that are “ions” in solution, which means they are able to transmit electrical impulses. Our brain and muscles depend on these electrical impulses for communication, and when the concentration of electrolytes in the bloodstream is too high or too low, that communication is disrupted, leading to potentially serious problems.

Sports drinks also provide a little bit of carbohydrate (usually in the form of sugar), which helps fuel our muscles. Carbohydrates are the fuel for our muscles (like gas fuels a car), but the body can only store a small amount of carbohydrate. When cycling for a long time, our muscles can “use up” any carbohydrate stored in the body and then will need us to consume more carbohydrate (more on carbs in a future post). Just like a car that runs out of gas, if we don’t fuel our bodies we’ll be stranded too!

So, the most obvious answer to the question of why we need to think about fluids during endurance exercise is that fluids keep us alive! But, in addition to that, staying well-hydrated also keeps our bodies running smoothly and lets us enjoy the ride.

Ride on!
Shelley