Beat the Heat to Keep Fit!

Beat the Heat to Keep Fit
Phil Hueston, NASM-PES; IYCA-YFS

Ok. So it's hot. Really hot. But you still want to get your exercise in. Is it safe? You're asking "How do I know when to go out and play in the summer sun (and heat)? How do I know when I should stay inside and exercise in the AC? Or should I bag it all and just hit the pool?"

There are risks and benefits to exercising in the heat. More risks than benefits, I'm afraid, but we'll talk about both.

First, the benefits.

Benefit #1 - No snow. Ok, just kidding. The first benefit of exercising is in heat that you will definitely break a sweat. This is really only a benefit if you intend to sweat, of course!

Sweating is good for the body in several ways. 1.) It is a very efficient way to remove toxins from the body. Sweating helps clean the toxins out of your body, helping to somewhat lighten the load on the kidneys, liver and other "clean-up" organs. 2.) Sweating is said to be moderately beneficial to cardiovascular health. When we begin to sweat, our heart and lungs work a bit harder to take in and distribute the oxygen needed to cool blood and keep organs and other body components cool. This contributes to improved cardiovascular strength and efficiency. 3.) Sweating can make you more beautiful (or handsome.) Sort of. See #1 - sweating clears toxins. The pores of the skin are often clogged with toxins, so when you sweat, you clear them out and let them "breathe."

Benefit #2 - Improved stress levels and management. Exercise helps manage stress under just about any circumstances (except, of course, gladiator competitions and being chased by a tiger - very stressful.) Benefit #1 may contribute to the increased stress management when exercising in the heat. Sweating more is said to trigger endorphin release sooner during and after exercise. No conclusive proof of higher endorphins in the heat yet, but there IS something to be said for how great you feel after a good sweat and challenging workout in the heat.

Benefit #3 - Muscles tend to warm up faster. It just makes sense - higher temperatures lead to more blood flow faster. Since that's a large component of how muscles warm up, heat helps.

Benefit #4 - Enhanced fat loss. While the majority of weight lost through sweating is water weight, heat helps in fat loss, too. Higher temperatures help heat the body. This makes fat more "fluid," for lack of a better term. Essentially, it becomes more easily transported in the blood, making it available for use as a fuel.

Benefit #5 - This benefit is a bit more specific in nature. Apparently, training in high temperatures can improve athletic performance at lower temperatures. According to a University of Oregon study, the results of which were published in the October 2010 issue of The Journal of Applied Physiology¸

"Heat acclimation improves the body's ability to control body temperature, improves sweating and increases blood flow through the skin, and expands blood volume allowing the heart to pump to more blood to muscles, organs and the skin as needed." - Science Daily, October 25, 2010.

The study was conducted on cyclists and found that their performance improved by 7 percent after only 10 heat acclimation exposures. Doesn't sound like much until you think about what a 7% reduction would mean for Lance Armstrong's fastest Tour de France time. In 2002, Armstrong finished in 82 hours, 5 minutes. A 7% improvement in that time would make it 76 hours, 21 minutes. 7% indeed.

So heat offers some unique benefits relative to exercise and the results you can expect. However, there are risks. So before you go hopping on the bike or grabbing your barbells, let's make sure you know what they are.

Risk #1 - Increased Cardiovascular load. In the heat, your body tissues increase in temperature, often beyond the normal range for average temperature exercise. In response, blood is sent to the skin to cool the body. Add to this the fact that sweat doesn't readily evaporate (how we cool off) and the job is tougher. This leaves less blood available to travel to muscles. That makes the heart work harder, stressing it.

Risk #2 - Heat Cramps. Less blood to muscles means higher risk of cramping. Heat cramps are painful muscle contractions, most often occurring in the calves, quadriceps and abdominal muscles. While the skin and body temperature may feel normal, the muscles themselves may be firm to the touch or even somewhat swollen.

Risk #3 - Heat Exhaustion. In this dangerous situation, your body temperature may rise to 104 degrees. It may be accompanied by nausea, headache, vomiting, dizziness, weakness, fainting, and cold, clammy skin. If no action is taken to alleviate it, heat exhaustion can lead to heatstroke.

Risk #4 - Heatstroke. Your body temperature reaches more than 104 degrees. This is a life-threatening situation and must be addressed immediately. Without immediate attention you risk organ failure, brain damage or even death. While the skin may be hot, your body may stop sweating, preventing cooling from happening. Confusion and irritability may ensue. Seek medical help NOW!

Beware the warning signs. Know the warning signs of heat-related illness or conditions. Muscle cramps, nausea or vomiting, weakness, headache, dizziness and confusion are all signs that it is time to stop, cool down and re-assess the exercise session based on the risks.

How to get the benefits without needless risks. You can enjoy the benefits of hot temperature exercise while minimizing the risks. Remember these guidelines:

  1. Know the temperature - Be aware of weather forecasts and temperature expectations. Generally, temps or heat indices over 100 are signs that you should take extra caution when exercising. Reduce the intensity of your session or use a shorter duration during these situations.
  2. Get adjusted and acclimated - Increase the intensity of your exercise over time, say 1 to 3 weeks. If you've been working out indoors or in climate controlled areas, start with a few short (20-30 minute) session in the higher temperatures and work up from there.
  3. Know your limits - High heat is not the time to "jump back in" at full effort if you've been slacking off or exercising at low to moderate intensity. Also, stick with what you know while adjusting to the heat. Familiar exercise types allow you to recognize your limits - which will be tested in warm temperatures faster than in moderate ones.
  4. Hit the fluids - HARD - Drink more fluids than you think you need. Don't wait until you are thirsty. By then it's too late - dehydration is beginning. For sessions longer than an hour, sports drinks may be a better choice because of the sodium, chloride and potassium they can replace. Choose drinks with lower sugar contents. Avoid alcoholic beverages during hot weather activity.
  5. Avoid the mid-day sun - Morning or evening are best. Even better - a brisk swim.
  6. Dress right - You may think your solar sweatshirt and the hot weather are a great way to drop a few pounds, but it's really a recipe for heat related illness, even heart attacks and strokes. Light, loose fitting clothes in light colors are best. Think about a hat - especially those of you (me too) who are bald, shave our heads or have thinning hair.
  7. Have an alternate plan - Go climb or run some stairs in an air-conditioned building. Exercise indoors in the air-conditioning. It's okay, the weather will cool off and you'll be outside again soon.
  8. Know your risks - Be aware of any medical conditions that might be made worse through heat exposure. If you aren't sure, speak with your doctor before beginning an exercise program in hot weather.
  9. Sunscreen, baby-Because sunburned skin doesn't cool off as well as healthy skin.

So the temperature has climbed into the high whatevers. Don't let that stop you from "getting after it." Just get smart about it and you'll be able to benefit from your hot weather workouts while avoiding the potential dangers.