Exercising in the Heat – Safely

Ah, summer! Long sunny days, warm evenings, more time in the great outdoors. After a long, cold winter, we just can’t wait to get out and enjoy the road, the water, the trails. Out comes the bike or the kayak — or both. The garden calls, and why not enlarge it this year? And let’s build that deck we’ve been talking about.

Not so fast, say health care providers who deal with the results of our plunge into summer. “Most people aren’t aware of the special risks of summer activity,” says Dan Levesque, an exercise physiologist at the Wellness Center of Monadnock Community Hospital in Peterborough.

“There are dangers in summer that aren’t apparent at other times of the year. Any time you exercise at temperatures of 80 degrees or more, there is additional stress on the body. Both muscles and skin are demanding oxygen. Heat builds up in the body.”

The risk of heat stress, heat exhaustion and heat stroke is real. Muscle cramps may be the first signal. Our bodies have to discharge the heat, and at body temperature the only way is by evaporation.
In the first several days of hot weather, we sweat less and the sweat contains more salt. Electrolyte imbalance may occur. As we become adapted we sweat more, with more dilution, cooling the body more effectively. But we need to acclimatize. At the first sign of heat stress, he advises, slow your pace, drink water and get out of the sun. If this doesn’t give relief, take a long, cool shower and rest.

“Many people overlook the impact of humidity,” adds Levesque. “At high humidity, we are not able to evaporate the moisture. There is more discomfort and more risk. If your body gets really moist, dry off, get rid of that moisture, wipe away the sweat.” 

He advises doing strenuous activity in the cooler hours of the day. Stay well hydrated and eat fruits and vegetables; they are rich in electrolytes. Sports drinks are also effective.

Exercising in the heat can help speed up acclimatizing, but you must begin slowly, be consistent and increase gradually. Exercise of up to an hour a day for three to five days should be sufficient for cardiovascular acclimatization. It can take up to 10 days for maximum sweat effectiveness.

Levesque recommends the “10 percent rule”: Increase the time of your run, for example, by no more than 10 percent a week. 

At either end of the age spectrum, there is increased vulnerability to heat. Small children and frail elders should be very careful to stay cool and well hydrated. Even active, fit older people will need to allow for a slower acclimatization. Levesque recommends wearing light-colored clothing for better dispersal of body heat. 

Muscle tears and strains are more prevalent during the summer. Often this is the result of poor judgment, according to Levesque. A person who is working on a project or taking a long hike on a hot day may forget to stay well hydrated and to take breaks. She may not be not thinking as clearly as she should. “Be aware of how you feel,” he cautions. “Think about what you are doing.”

Mark Carota is a physical therapist and certified strength and conditioning specialist with HealthSouth in Keene. Carota sees the “weekend warrior” phenomenon as a factor in many summer injuries.
“To stay in condition, you must exercise at least two or three times during the week,” he says, “otherwise you are much more likely to experience pulled muscles and sprains.”

Ankle injuries and plantar fasciitis, an inflammation of the heel, are more common in the summer. There is more shin and calf pain. Part of the problem, he explains, is the result of switching from boots or running shoes to sandals. Even a person who exercises regularly may have difficulty when wearing shoes without arch and ankle support.

The fascia (fibrous connective tissue in the foot) has to stretch suddenly to accommodate to the sandal. It may begin to fray. 
Each sport, it seems, carries its own risks. Swimmers are more likely to experience bursitis or tendonitis in the shoulders.  Hikers may get hamstring pulls and walking or running on uneven ground often leads to ankle problems. For ball players, especially children, broken bones are a typical summer injury. Fortunately, children generally heal well and bounce back.

If it seems that summer is a trap for the unwary, however, don’t despair. What makes for summer fitness really isn’t rocket science; it’s common sense. The prescription for summer fitness begins with what most of us know, even if we don’t practice it.

Build up endurance gradually through consistent exercise. Carota emphasizes the importance of balance in muscle development. Underdeveloped back muscles, for example, will result in a forward-leaning posture and strain the neck. Maintain flexibility through regular, gentle stretching. Begin your activity only when your muscles are warmed. Wear shoes with support for strenuous activity. Stay well hydrated (soda doesn’t count). Pay attention to your body and its reaction to heat. 

Summer in New Hampshire is a delight. It’s a great time to take advantage of the longer days for your favorite activities. Just remember to slow down a little, and you’ll enjoy it more. NH

Monadnock Community Hospital Wellness Center, Peterborough
(603) 924-4650

HealthSouth Sports Medicine and Rehabilitation Center, Keene
(603) 352-6043