People with chronic health problems or conditions - known as "special populations" to the health care establishment - need not deprive themselves of exercise. Where there's a will there's a way, and you can succeed if you take it easy and listen to your own body.

So says Gwen Hyatt, an exercise physiologist at Logan Regional Hospital and proprietor of her own Desert Southwest Fitness in Logan. Hyatt also consults and provides continuing education programs and classes for fitness professionals, in person or by correspondence. She holds a master's degree in exercise science from the University of Arizona, and a gold certification from the International Dance Exercise Association.Lately she's been developing courses of exercise for people with such chronic conditions as diabetes, arthritis and heart disease. She also deals with the special requirements of exercise during pregnancy, and has developed "FITPLAY," aimed at building healthy lifestyles for children.

Each special population has its own limitations and guidelines, she pointed out.

"If diabetics undertake an exercise program, consistency is the key, and well-conceived and well-performed exercise can be a big factor in controlling the disease, along with proper nutrition and medication," she said. "Of course a diabetic should have his/her physician's release before attempting any exercise program.

"Diabetics should exercise five to seven days a week - at the same time, for the same duration of time, at similar intensities. Ideally they should check their blood sugar level just before and after exercise until they get their program established, since exercise facilitates the use of glucose, affecting the receptors that allow it to penetrate body cells.

"They should always carry a complex carbohydrate snack for emergencies. And if all is going well, they should have no problem mainstreaming into conventional exercise programs, working at low to moderate intensity.

"Diabetics should be careful where they inject insulin, avoiding the major muscles groups that will be exercised. For example, insulin should not be injected into the quadriceps area, if walking is anticipated. The abdominal area is good for those who contemplate walking, biking, stair climbing or other exercise that uses large muscle groups.

"They should also be aware that cold weather slows down the absorption of insulin; hot weather speeds it up. And they should practice good care of the feet, immediately treating hot spots, bunions, blisters or callouses."

Heavy weight lifting or body building are unsuitable exercises for diabetics, said Hyatt, since they increase blood pressure, with risk of retina hemorrhage. Exercise may be risky for diabetics with retinopathy or peripheral nerve damage, because high blood glucose can damage nerve endings and blood vessels. "And diabetics with blood sugar above 250 should not exercise; some experts think even 200 is too high," she said.

Hypoglycemia, or low blood sugar, a condition that may be experienced during exercise, can be recognized by the symptoms of dizziness, shakiness, headache, sweatiness and irritability. If a diabetic has such a reaction, he or she should stop exercise for the day and eat a complex carbohydrate snack of orange juice, fruit or crackers.

Hyatt does not recommend that a diabetic exercise during pregnancy, unless suggested by her physician. A few women will develop gestational diabetes, with symptoms that abate after delivery. However, such women should be aware that 50 percent of them will have a recurrence of the disease later in life.

As for arthritis, Hyatt suggests that 50 percent of the population now has or will have arthritic symptoms during their lifetimes, ranging from a little discomfort to extreme pain and deformity.

Their goal in exercise should be to maintain and restore as full a range of motion as possible in the joints, and help stabilize the joints by maintaining or restoring strength in the musculature and connective tissues surrounding them.

Arthritics should work on posture, balance, coordination and body mechanics, none of which they can take for granted. "An arthritic joint is already under stress," said Hyatt, "and misalignment of the body can make the joint movement even more jerky and less integrated."

An arthritic's workout should consist of simple things - sitting, standing and walking techniques and proper body mechanics - to maintain the highest quality of life possible. "Side effects of the disease - fatigue and joint pain - contribute to a deconditioned state of being," she said.

"Relaxation techniques are important for rest and relief of muscular tension, which results in stress on the joints. Deep breathing exercises can also be valuable, especially if there is arthritis in the rib cage, for they will help to maintain optimal breathing function, and may help to alleviate discomfort."

Hyatt recommends applying the two-hour pain rule: If two hours after exercising you have more pain than normal, you have probably exerted too much. But the long-term aim should be increasing exercise for longer periods. She suggests slow, gradual warm-ups 10 to 15 minutes, to prepare the body, along with progressive cool-downs.

She also recommends not overloading the joint areas with too much exercise at too high of intensity. "Avoid positions that compromise affected joints," she cautioned. "For example, if arthritis is in the hands and wrists, a hands and knees position on the floor would be inappropriate."

Non-weight bearing exercises are best for arthritics, such as using the rowing machine, bicycling or swimming. Isometric exercise (working one set of muscles against another) is also good, since it usually does not stress the joints, while strengthening the surrounding tissues.

Symptoms that signal overexertion are excessive fatigue, or hot joints that are painful, red and swollen. Avoid such high-impact exercise as basketball and volleyball.

Hyatt noted that the Arthritis Foundation can be very helpful, recommending the organization's PACE (People with Arthritis Can Exercise) video and aquatics program.