It’s June already, school is out, the tourist season has started, and the heat seems to be on full force with recent heat indexes of 100-plus degrees.

Since it’s going to get progressively hotter as summer moves along, this would be a good time to remind everyone here in the Lowcountry (especially tennis players) about hydration, i.e., taking in fluids.

No matter what the activity, athletic or otherwise, staying hydrated is crucial for the best performance and comfort.

Tennis can be especially taxing just by the nature of how it’s played, and many people are dehydrated before they even hit their first ball, causing their physical and mental performance to be compromised.

If you experience low energy and lack motivation to work out, it could simply be due to a lack of enough fluids in your body.

Results from different studies show that a 2% loss of body water can equal a 20% loss in performance, meaning your power, strength and speed. And, as if that isn’t enough, dehydration can have a huge impact on cognitive skills, too.

It’s pretty easy to become mildly (1% to 2%) or moderately (2% to 5%) dehydrated, and it can happen during normal daily activities. Because we usually don’t start to feel thirsty until we’ve lost 1% to 2% of our body water, lots of people are mildly dehydrated all day.

Studies on cognitive skills have also shown dehydration of 1% to 2% has little effect. But when it got over 2%, the “pay attention” skill set rapidly declines.

There was also a significant, negative impact on motor skills, especially skills employed by tennis players.

Still more studies show that a loss of about 2% body water produces headaches, difficulty concentrating, and fatigue. Along with all this, performing while dehydrated makes the brain work harder to achieve the same levels as when properly hydrated.

Here are a few tips to help maintain good hydration on the court:

• Drink a glass of water upon waking up every morning and before going to bed at night.

• Drink regularly during the day. Waiting until you’re thirsty means you’re already dehydrated.

• Drink about 4 cups of water per hour of intense exercise.

• Regarding caffeinated drinks, add 1 to 2 extra cups of water for each cup of the drink consumed.

So, how much water should you drink? Since there isn’t a “one size fits all” answer, the best way to know is to observe the color of your urine. It should be almost transparent. If not, simply drink more. Even though it’s possible to drink too much water, it’s not nearly as common as dehydration.

Drinking water regularly helps make you feel great, stay focused, and be motivated to play your best tennis while the heat is on.

Lou Marino is a USPTA Cardio and youth tennis coach who lives, teaches and provides custom-hybrid racquet service in the Bluff-ton-Hilton Head Island area. lwmarino@hotmail.com