The health benefits of swimming are well-known. But did you know that spas and saunas offer health benefits as well?       For centuries now, health conscious people have recognized the benefits of soaking in natural hot springs.   As far back as the ancient Egyptians, hot springs have been cherished as places of soothing retreat and as a relaxing means of reducing pain. In recent years, hot water therapy has gained the endorsement of physicians and athletic trainers for the treatment of pain and injuries. Soaking in a spa or relaxing in a sauna promotes health in several ways.       Immersion in warm water speeds up the body's natural healing process and helps to relieve muscular pain.   Soaking in a spa increases circulation by raising body temperature and causing blood vessels to dilate. The resulting increased blood flow speeds up the body's natural healing process. The massaging action of the jets loosens muscles and pushes toxins out of the sore area. In addition, high heat stimulates the body to release of endorphins, the body's naturally occurring painkillers. Water's buoyancy reduces body weight by about 90%, so pressure on joints and muscles is relieved. This often allows people to get needed exercise, condition and strengthen muscles, without placing undue stress on their joints.     The Arthritis Foundation has documented that hydrotherapy can be beneficial in easing the muscle pain and fatigue caused by arthritis, fibromyalgia and related diseases.   In addition, they found that hot water therapy decreases swelling and stiffness, and helps increase flexibility and range of motion. Saunas, using infrared, dry or steam heat, provide many of the same benefits of soothing muscle aches and pain.   By speeding up the elimination of lactic acids from muscles, warm therapy can also ease muscle pain and fatigue caused by strenuous exercise. In addition, saunas induce deep sweating, reducing toxins and cleansing the skin. Calories are burned through the sweating process and through accelerated heart activity.   Warm therapies may also help you sleep better, according to the National Sleep Foundation and other medical researchers.   While in a spa or sauna, the core body temperature is raised; the body temperature drops after leaving the warm environment, which may be a signal to the body that it's time to sleep, easing the transition into a deeper sleep. A spa is also a great stress reducer. The relaxing properties of the water in itself may have sleep-promoting effects. Additionally, pain is often a problem that causes people to have trouble sleeping. Pain, anxiety, and lack of restful sleep frequently occur together in an escalating cycle that is difficult to break. The healing waters of a hot tub may help to break this cycle.         Besides promoting better sleep and an increases sense of well-being, a spa provides safe "exercise" for people who cannot exercise rigorously.   A Mayo Clinic study indicated that soaking in a hot tub for 15 minutes induces mild cardiovascular stress, recommended for people with heart disease. Regular sauna use can also improve heart rate and cardiac output. Increased blood flow also is helpful to those with circulatory problems, such as certain cardio-pulmonary issues, certain types of diabetes, varicose veins and swollen ankles. In addition to the benefits of increased circulation, the hydrostatic pressure exerted on the body by the water approaches the pressure in the venous system. According to Doreen M. Stiskal, Ph.D., assistant chair of the graduate program at Seton Hall University in South Orange, N.J., "Within 30 minutes of exposure, the pressure 'pushes' water out of the spaces between tissues and back into the vascular system for elimination by the body."   Spas may also be beneficial to people with diabetes.   In 1999, the New England Journal of Medicine documented several health benefits of soaking in a hot tub for people with type 2 diabetes mellitus, such as reducing blood sugar levels by 13%. New hot tub users should vary the temperature and length or soaking time to determine what is most comfortable. Water temperatures will normally range from 98-104 degrees F. with soaking times of about 10-15 minutes. Keep in mind that children and elderly people are more prone to become overheated and may need to adjust temperature and soaking time according to their personal limits. It is advisable to get up slowly when getting out of a spa or sauna because blood vessels will be dilated. Getting up slowly will help avoid orthostatic hypotension, a drop in blood pressure when you sit or stand too quickly after lying down or sitting, which can be a concern for some people. ***It is important to follow your physician's guidance about time limits and temperature of spas and saunas.