On a summer morning in Lake Seminole Park in Florida, I was teaching a racewalking lesson when we passed a hefty gentleman huffing and puffing as he was doing his version of exercise walking while wearing sweat pants and a sweatshirt.  July!  Florida!  Where is his sense? 
 
I held my tongue, hard as it was.  My husband has accused me of giving exercise instruction, even when none is requested.  I talked to myself – "Bonnie, he’s not your student.  It’s not your business what he wears.  Not everyone wants your exercise advice."  I took a deep breath and racewalked past him with my student. 
 
I tried to put him out of my mind.  At the end of our lesson, my student and I were finishing stretching at a picnic table when the gentleman came around the bend and headed toward his car, beat red in the face.  While my student walked toward her car, I walked toward him.
 
"Sir, I noticed your sweat outfit.  It’s 85 degrees this morning.  May I ask why you’re wearing sweats?" "Sure," he offered, "I’m hot as heck, but it’s a good way to burn more fat.  I have a lot extra fat to get rid of," as he grabbed hold of his big belly to prove his point.  "I need to lose this weight quickly."  At the very least, I justified that by keeping him standing and talking to me, I was preventing him from jumping right into his car and sitting (heart attack?) without a proper cool-down, and with that red face.
 
The myth that sweating can help you burn more fat has been perpetuated for years.  Many of us have seen new exercisers in gyms, all bundled up working out and sweating profusely.  Yet, they keep their sweatshirts on, mistakenly believing that it will help them lose weight. Yes, they may lose some superficial water weight, but that’s all it will be – water.  As soon as they drink, their weight will come right back.
 
In fact, wearing sweatsuits or other heavy clothes in hot weather is a dangerous detriment to your walking or exercise program.  When you wear hot clothes, you cause your body to perceive the weather as being even hotter and steamier, so your heart begins to work harder to pump more oxygenated blood to the surface of the skin in order to produce more sweat.
 
Sweat is our body’s mechanism for keeping the skin surface temperature regulated.  That gentleman’s body didn’t realize that he was wearing those hot clothes on purpose.  His body thinks, "Oh my, it must be REALLY hot in Florida today.  I need to work harder to get more blood to the surface of the skin." The heart works plenty hard exercising in hot and humid weather – no need to stress it even more.
 
Here’s a big surprise for those who think that exercising in heavy clothes will burn extra fat.  You’ll actually burn LESS fat.  Since your body has only a certain amount of blood to send through the body, it must make a decision.  Should it send that oxygenated blood to the working muscles in order to burn fat or should it send that blood to the skin’s surface to help you sweat and keep you alive?  Guess what your body chooses? 
 
If you’re looking to lose weight and stay fit this season, certainly keep up your walking program.  By carrying water with you in a fanny pack, you should be able to keep up your workouts throughout the warm weather.  Alter your exercise walking by going out early or since it stays light late, you can go out after dinner.  If you have access to a treadmill, try your workout indoors when it’s hotter than normal.  But please no sweat clothes in warm weather!
 
Stick with lightweight, coolmax shirts and microfiber (not cotton) shorts. Use a visor to shade your face, and always wear UV protection sunglasses. Wear the least amount of clothes that you feel comfortable with.  That way, you’ll burn the most fat and calories that your body can.  But, please - - - no naked walkers in Lake Seminole Park, nor anywhere else I do lessons.
 
Bonnie Stein, M.Ed., CPTS is a racewalking instructor and certified personal training specialist based in Redington Shores, Florida.  Please visit www.AceWalker.com.