August is typically one of the hottest months of the year where average temperatures here in the ATL typically peak around the mid-90's each day. Combine that heat with high humidity, and the heat index (also known as "How hot it feels) can easily approach 105 or higher. With outdoor athletics kicking in for many people, especially youth athletics, it is very important to follow some simple guidelines, not only for health and safety reasons, but also for athletic performance purposes.
As everyone has seen in the news, recently there were some preventable fatalities in sports because of heat stroke and exhaustion. The simplest way to stay healthy and safe in the heat is to stay hydrated. Your body has an incredible ability to cool itself during activity and heat, but this system only works when you are properly hydrated. This may sound like a simple statement, but all too often people unintentionally under-hydrate prior to an athletic event, usually because we don't fully understand how the environment affects our bodies cooling capability.
We all know that we are active in a hot environment we sweat more as our bodies try to compensate for the higher core temperature. What you probably don't know is how the system actually works. The cooling mechanism actually resides in the evaporation of sweat from our skin. Without getting too geeky and discussing fluid dynamics and heat, when the sweat evaporates from the skin it has a cooling affect for the skin which then cools the blood, keeping our core temperature at a safer level. If we run out of water, we run out of sweat, which leads to an inability to the cool the skin, and subsequently an inability to lower our core temperature. That's when all the bad things happen.
Humidity complicates this because the more humid it is, the lower the evaporation rate. Your body responds to the lower evaporation rate by pumping out more sweat which means your dehydrate yourself quicker. Throw in a good amount of caffeine (a diuretic) or some alcohol (again, a diuretic) and the risk of dehydration increases even more.
On the performance side, improper hydration is the #1 factor that leads to a decline in athletic fitness and ability. A 2% drop in body weight because of lowered hydration can equate to as much as a 20% drop in performance metrics. So, if a 150 pound athlete loses 3 pounds of body weight because of sweating (a gallon of water weighs 9 pounds...), that person's athletic ability will decrease quickly.
Now, there are plenty of signs that let you know that a heat related illness is developing. The key thing is to identify Heat Exhaustion prior to things getting worse. Signs of heat exhaustion include dizziness, headache, profuse sweating, rapid shallow breathing, cool clammy skin, a rapid weak pulse, and an uncoordinated gait or decrease in balance and coordination. Heightened thirst is also an early sign of under-hydration. You should never go into an intense activity feeling thirsty; it is a red flag that your body is already improperly hydrated.
If you or someone you see is experiencing heat exhaustion, the first thing to do is to stop the activity and start the cooling process. Obviously the person needs water, but shade and a cool, wet cloth go a long way in speeding the cooling process. Now, we all know how great a cold cloth feels on the back of our necks when we are hot. The problem is that this is not a good way to cool yourself down. It feels good, but it is actually tricking your body. Your bodies ambient temperature receptors are on the back of your neck, and those sensors are involved in determining how much you should sweat. If you cool off the back of the neck, your body thinks it is cooler than it actually is and decreases its efforts to cool the body. Instead take the cold cloth and put it on top of your head to cool your brain, and then take a second cold wet cloth and hold it between your wrists. This will cool the blood flowing through the veins and arteries that are closest to the surface which will help circulate cooler blood and lower your core temperature.
Now, the defense against heat exhaustion is to properly prepare to be active in the heat. Here are my main suggestions:
1) Consume lots of water prior to the event...if you haven't figured that one out already, we are going to have to work on your reading comprehension skills.
2) Check your pee...sure I could have said urine, but then you wouldn't have just made that "I can't believe he just wrote that" face. Seriously though, if my athletes are not urinating clear or pale yellow prior to an event, I make them drink more water. Dark yellow urine means you are underhydrated, or just ate 4 tablespoons of salt. If your urine is bright yellow, you probably consumed too many Flintstones vitamins.
3) Don't be vain: Function before fashion... white clothing reflects heat, dark colors absorb. I know most people think of this as a "Well Duh" statement, but after running 3 summer speed and agility clinics this summer, I know that people don't think of this like they should.
4) Sit your butt down!... even brief (2-3 minute) breaks 2 to 3 times over the course of an hour are beneficial to staying cool. During these breaks, you should sip water. If you can get into the shade, even better.
5) Develop an in-game drinking habit...For water that is...I generally suggest a 2:1 or 3:1 ratio of water to sports beverage in order to maintain electrolyte levels, but if the event is less than 90 minutes (and you are properly nourished) more than likely you can get away with just water during the event and then get your electrolytes afterwards.
6) Take a look at yourself...if you feel dizzy, stop. If you feel nauseous, stop. If you develop a headache, stop. If you feel like you need to chug a gallon of water, stop. If your opponent just took you to school, you need to come in a train more at Strength Lab!
7) Avoid the things that make you pee...sorry I just had to say it again. But in all seriousness, prior to being active in the heat, you should avoid consuming alcohol and a lot of caffeine. A little caffeine can be a powerful ergogenic (sports performance) aid. A lot of caffeine can cause major issues with hydration status. If you have an 8:00 AM match, don't drink a 12 pack of beer the night before and chase it with a pot of coffee before the match.
If you have any questions, as always, you can reach me at firstname.lastname@example.org or my personal e-mail address if you have it.