Health Plus
June 14, 2019

Blair Hitchcock, Director of Sports Nutrition at Vanderbilt, discusses why proper hydration is important for physical activity, signs of dehydration, and current recommendations for hydration for physical activity.

Begin Transcript

Bridgette Butler:  Welcome to this edition of the Vanderbilt Health and Wellness Wellcast.  I am Bridgette Butler with Health Plus.  Nashville certainly sees its share of hot days during the summer, but we don't want to let that stop us from being active.  Whether you are exercising outdoors or in, proper hydration is very important for your health.  Here to speak with us today about hydration and exercise is Blair Hitchcock, Director of Sports Nutrition at Vanderbilt.  Welcome, Blair.
 
Blair Hitchcock:  Hi, thank you.

Bridgette Butler:  Blair, why is hydration important for exercise?

Blair Hitchcock:  Hydration is super important just from the aspect of making sure your body is healthy and happy and moving the way it is supposed to be.  So, your muscles are actually 75% water.  So, if you don't have enough water, you are more at risk for injury, ripping/tweaking those hamstrings, or any other type of muscular injuries.  Also, it helps your joints.  It keeps your joints nice and loose and able to move and do the activities that you are wanting to do.  Hydration is really important just from a mental aspect as well.  So, if you lose 1-2% of your body weight, which is not that much, it impacts the way you think and process information, and you have a decrease in performance.  So, if you are a runner and running outside, and you are not properly hydrated, you are not going to be able to run as fast or make the times that maybe you are pushing for or train as long as you want to.  So, if you are a little bit more proactive in the hydration process, it allows you to push yourself a little bit further while you are recreationally training outside or working out and moving your body in the summer.

Bridgette Butler:  Well, that is so interesting.  It affects both the physical and the mental.

Blair Hitchcock:  Yes, it does, it does.  It affects a lot more than, I think, people realize.  It is something you have to be very proactive about, and so, it is hard to do, but it is very important.

Bridgette Butler:  What are the signs of too little hydration?

Blair Hitchcock:  Usually, you can tell you're dehydrated.  A good way to check is to check the color of your urine.  If your urine is not clear or pale yellow, you are probably dehydrated, and that is an easy indicator that you can just kind of like look and see.  Another thing is a headache or fatigue is also a sign of a little dehydration, and then sometimes, just you're thirsty.  So, don't forget those things, too.  I know there's a pretty good debate on "drink to thirst or not," but if you're thirsty, then I would say you are obviously probably on your way to dehydration or you probably should drink something.  So, I think those are indicators of signs of little hydration.

Bridgette Butler:  And what are the recommendations for hydration for exercise?

Blair Hitchcock:  Usually, I would say a baseline is half of your body weight in ounces of water is just like your baseline every-day hydration.  If you're a heavy sweater, or if it's hot outside, or if you've been working out for longer than 60 minutes, I think that's kind of when you start to add those electrolytes back in and add those Gatorades and those products.  You don't need them unless you are working out for longer than an hour.  It's a really good point to remember - if you are moving for a weight loss goal, to keep that in the back of your mind of what your goals are actually trying to do, and then you can add in the fluid.  So, a one-pound loss is a liter of fluid you have to add onto your baseline.  You have your ounces of water that you need in a day, right?  If you are 120 pounds, you have 60 ounces of water you need in a day.  You go out and you sweat and you lose a pound, so you will add a liter to that 60, and that would be the amount that you need in that day.  Post workout, you will be thirsty anyway, so you would probably drink that liter, but you just have to continue to meet your goal, your daily goal.

Bridgette Butler:  So, important to be thinking about drinking water is for exercising and then potentially a fluid that has added electrolytes if we have been exercising more heavily?

Blair Hitchcock:  Correct, yes.  So, my rule of thumb is - if it's hot, if it's humid, or it's a hard intensity, that's kind of where those electrolytes are really needed, because if you drink a lot of water but don't replace the electrolytes, you are not actually hydrated.  Hydration is a combination of fluid and electrolytes.  It's just, usually, most people don't have hard enough activities and so you don't necessarily need the electrolytes because we have a really high sodium in our diet, and so you don't need to add more electrolytes to it, because your sodium content is probably high enough in your diet; however, if it's really hot, really hard workout, or really humid, your sweat rate is probably going to be higher than normal or expected, and therefore, you may need to supplement with some electrolytes, like a Propel packet or a BODYARMOR Lyte or those types of products would be the best.  And then if it's for a performance, like if you are playing a soccer game outside, and it goes two hours long, then that's kind of where that Gatorade or Powerade or Full BODYARMOR may kind of go into that category.  And then don't forget about food, and like, fruits and vegetables also have a water content in them.  So, you can also eat your water, essentially, to make sure you're hydrated.

Bridgette Butler:  Interesting.  That is important to remember, all the different sources of fluids and hydration.

Blair Hitchcock:  Right, and I think it's really fun, too ... like, you can add fruit-flavored water and you can add different things to your water to make it taste better if you don't just want a water, so limes, lemons, berries.  You can do frozen fruit.  You could do it, and it will just kind of like leach into the water and it will give you that taste.  So, to kind of liven it up, sparkling water, I know, is a big trend these days.  So, if you want to do that, that would be great, too.  It's still fluid, and so those are still positive for your body.

Bridgette Butler:  Sounds very refreshing.  Well, thank you so much, Blair, for sticking speaking with us today.

Blair Hitchcock:  Yeah, absolutely.

Bridgette Butler:  And helping us better understand hydration and exercise.

Blair Hitchcock:  Yes, ma'am.  Thank you for having me.
 
Bridgette Butler:  Thanks for listening.  If you have a story suggestion, please email it to us at health.wellness@vanderbilt.edu or you can use the "Contact Us" page on our website at www.vumc.org/health-wellness.