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MIAMI - Pro boxer Jermain Taylor gets up earlier. Anesthesiologist Philip Zwiebel swaps marathons for triathlons and Ultimate Frisbee devotee Lois Gramley isn't above dousing herself or pals with ice water on the playing field.
Beating the heat smartly. It's critical during these summer months, when working out in the heat and humidity can take a serious toll on your health.
Indeed, more people in the United States died from extreme heat than from hurricanes, lightning, tornadoes, floods and earthquakes combined during a 20-year period ending in 1999, the Centers for Disease Control and Prevention reported. This means that approximately 175 Americans will die from extreme heat this year with the young, elderly, sick and overweight the most likely victims.
But the heat and humidity doesn't mean one has to grow into a couch potato.
"You can exercise high intensity in South Florida `if' you do it right," Zwiebel insists while standing outside a cycling shop.
To do it right, "Start low and go slow" medical experts advise.
When you work out in the heat your body loses fluids at the rate of a liter every 20 minutes or so. Along with the water shed, you're losing valuable sodium and potassium, electrolytes that keep the body's system functioning properly.
If you fail to replace the fluid you run the risk of dehydration and, in extreme cases, death. One guideline: If you don't have to use the restroom after an hour or so of physical activity, you haven't hydrated properly.
Swimming is no different from running or cycling, Zwiebel believes. "The water is too warm in South Florida."
Though water conducts heat away from the body, you can get dehydrated if you swim at a brisk pace for more than an hour. Keeping a water bottle at pool's edge is wise.
Eyeing only the thermometer is also foolhardy. Places like Las Vegas, Texas and Arizona, for instance, soar over 100 degrees but may actually be safer than the tropics.
The culprit? Humidity.
"The real problem in Florida, as compared to other places, is not just the heat but the humidity," says Dr. Andrew Sherman, a physiatrist specializing in musculoskeletal medicine and assistant professor of rehabilitation medicine at the University of Miami. "When you sweat it evaporates off and that's how the body cools... When you have humidity around 80 to 90 percent, you sweat and it just stays there on your body... a wet shirt lapping. It's not evaporating and so your core heat is increasing. The risk of dehydration and heat exhaustion is much higher."
This means you need to pay more attention to hydrating and avoiding middays when the temperature "and humidity" soar.
If the temperature reads 90 degrees, for example, and the humidity is 80 percent, the "apparent" temperature is 113 degrees. Your body reacts to this elevated temperature. In a place like Las Vegas, with a 90-degree reading and 20 percent humidity, the apparent temperature dips to 87.
Water is the best coolant for activities lasting under an hour, experts say. Sports drinks, despite their high sugar content, are good for those engaged in longer activities such as marathons or bike rides, as they replace lost electrolytes. (Those worried about the sugar can dilute the drinks with water.)
But one shouldn't wait to hydrate until the activity has begun. A study that came out two weeks ago by the American College of Sports Medicine found that two-thirds of American children are dehydrated before they begin practice.
"Predrink 12 to 16 ounces of fluid one to two hours before you exercise," Sherman suggests.
Thawing out after winter's hibernation can also lead to problems.
"Whenever one goes from a relative or absolute period of inactivity, people usually don't use the common sense necessary to realize they can't go immediately back to what they did before. The activity has to be gradual because the cardiovascular system . . . doesn't do as well with sudden exertions. This leads to heart attack, sudden death," says Dr. Stephen Glasser, a professor of epidemiology at the University of Minnesota. "You can get to a higher workload by starting low and progressing slowly without complications rather than going full bore."
Ironically, the risk of heart attack is greatest in the morning, a time of day experts recommend for outdoor activities. Working out on the weekends, after a Friday night of imbibing, adds to the risk of dehydration. Alcohol, as well as caffeine, is a diuretic.
"The caveat is, it's better to exercise at any time of day than not at all," Glasser said. "We don't want to scare people from working out or working out in the morning but each person should evaluate their particular risk."
So Taylor, the 25-year-old boxer, wears looser clothes, hydrates and starts his workout at 6 a.m. in the summer. "In the winter I get up later. I wait for the sun to come up. But I love training in Miami."
Gramley, a thirty-something registered nurse who chases the Frisbee or runs regularly, starts swigging water and diluted Gatorade before practice.
"We compete in tournaments that last all day so you don't want to start out dehydrated," she says. "I prefer to work out outdoors all drenching in perspiration. We rehydrate and keep going."
Which brings us back to Zwiebel. A triathlon? In the summer? Doesn't that sound, well, arduous?
"You're spending two-thirds of the training swimming and cycling," explains Zwiebel, 38, who has completed the grueling Iron Man race twice. "I found doing the triathlon is a major way to avoid the heat."
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SUMMER WORKOUT TIPS
- Drink fluids - at least 16 ounces - and drink 12 to 16 ounces an hour or two before working out.
- Water is best for activities lasting 30 minutes or less. For longer, more intense sessions, consume drinks that replace lost sodium and potassium. Dilute sports drinks with water to cut down on sugar.
- Wear lightweight, light-colored and loose-fitting clothes. Don't forget a hat.
- Use a strong sunscreen and reapply often.
- Avoid midday exercising; work out before 10 a.m. or after 4 p.m.
- Find a neighborhood with tree canopies and run under them.
- Route your run so that you can take a pit stop in an air-conditioned area. "The benefits of running won't be diminished if you stop for five minutes; in terms of getting your body temperature down it could be a major save," says Zwiebel.
- Run or cycle away from the wind initially so when you finish you'll head back into the wind and feel cooler.
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(c) 2004, The Miami Herald. Distributed by Knight Ridder/Tribune News Service.
