Six Signs of Dehydration

If you notice any of these signs, it’s time to hydrate, stat.

Whether you work out, drinking lots of water every day is important. It’s right up there with air—you need it in order to stay alive. But if you work out a lot, your need for water goes way up. In fact, if you’re not hydrating enough, you could be subjecting your body to some harmful side effects. Experts estimate that even losing just 2 percent of your body’s water weight can make you need 25 percent more water. 

Signs of dehydration

If you’ve been noticing any of these symptoms before or after your workout, it’s time to fuel up on some H2o ASAP.

You’re thirsty

You’re probably thinking, Well, duh. But according to certified personal trainer Brandon Mentore, once you start to feel thirsty, dehydration is already occurring. “The thirst sensation is an indication that you’re already dehydrated anywhere between 2-5 percent,” Mentore says.

You have a headache

Before you reach for that bottle of Advil, you might want to try a bottle of water instead. “Your brain’s ability to drain fluids depends partially on your hydration level,” Mentore explains. Being dehydrated can cause headaches, so if you’re experiencing head pain and haven’t had much water to drink, it’s time to fuel up.

You feel lightheaded

Becoming lightheaded is scary, especially if you’re in the middle of a class or behind the wheel of a car. Being dehydrated can cause this feeling to occur. “When you’re dehydrated, a lot of the water that you lose comes out of your bloodstream,” explains fitness instructor Henry Halse. “This means that your blood pressure will drop, since there is literally less blood in your body, causing light headedness and dizziness.”

Your muscles keep cramping

If you’re experiencing muscle cramps during your workout, you’re not hydrating enough. “Muscle cramps are simply a result of the electrolytes that are lost from sweat and water loss,” Halse explains. “Most of your tendons, ligaments and joint capsules are lubricated with synovial fluid for ease of movement and shock absorption,” Mentore continues. “Being dehydrated reduces the fluidity of joint capsules, making it more difficult for them to move and glide without friction, causing pain.”

Your muscles feel fatigued

If you start to experience muscle fatigue early on during class, a lack of hydration could be to blame. “Overheated muscle tissues, or thermal breakdown, is what causes your muscles to fatigue the fastest,” says Mentore. “Water cools the muscles down and will allow you to perform longer.”

You’re twitching

Yes, lack of water can even cause your nerves and muscles to twitch. “Your body’s fluid status makes a difference in the transmission of nerve impulses to all tissues,” says Mentore, “especially muscle tissue. Dehydration can cause random contractions, nerve misfires or static contractions, also known as tetanus contractions.”

The moral of this story? Hydrate, hydrate, hydrate! ” Have 1 to 2 glasses of water an hour before your workout,” Halse recommends. “It’s also wise to keep a bottle of water on you at all times to sip on during the day.”

Danielle Page is the founder of ThisisQuarterlife.com, a blog that provides necessary information for navigating the awkward phase of adulthood known as “quarterlife.” Danielle’s work has been featured on Cosmo, Woman’s Day, Your Tango, Bustle, The New York Times, Thought Catalog, Elite Daily and the Huffington Post.