Prevent injury while becoming physically fit Published Sept. 14, 2006 By Master Sgt. Darrell Mayers 20th Medical Operations Squadron SHAW AIR FORCE BASE, S.C. -- According to AFI 10-248, Fitness Program, all members of the Air Force must be physically fit to support the Air Force mission. With the inception of the Air Force fit-to-fight program, Airmen may be experiencing more knee, back and shoulder injuries. These injuries are mainly due to running and can be easily prevented, said Professor Timothy Noakes, author of "Lore of Running." A simple warm-up exercise such as a five-minute brisk walk, running in place or jumping jacks will allow the muscles to warm slowly, decreasing the chance of injury. Stretching loosens the muscles slightly and takes pressure off the joints. It is important that the warm-up exercise be performed before stretching, because it does not help to stretch a cold muscle. A cool-down exercise should take place after exercising as this lowers the intensity of the exercise and allows the heart to slow down and the muscles to relax. Afterwards, muscles need to be stretched once again. According to the 20th Medical Group, you can minimize the wear and tear on your body by replacing up to 25 percent of running with biking, swimming, deep-water running, elliptical training or other aerobic non-weight bearing exercises. According to 911th Airlift Wing Instruction 40-501, Air Force Reserve Fitness Program, temperature ranges from 32 to 92 degrees Fahrenheit are acceptable for sub-maximal walking exercise. Temperatures below 75 degrees F are not significantly affected by humidity and do not carry a risk of heat injury. Dehydration is not limited to the summer months, although it is more likely to occur during that time. Many physicians believe people who drink coffee, tea, soda and alcohol are at greater risk for dehydration. Those who consume these products should drink an equal amount of water. For physically active individuals, the potential for dehydration is even greater. The average sedentary person needs a minimum of 64 ounces of fluid per day. Water is best. According to Mr. Noakes, by monitoring the color of your urine, you can tell if you are well hydrated. It should be pale yellow or even clear. Dark-colored urine can be an indication of dehydration. There have been very few cases of people drinking too much fluid. This health risk is called hyponatremia or water intoxication, and can dilute the blood, leading in extreme cases, to serious medical problems or death. Mr. Noakes believes that the wisest approach to fitness is to listen to what the body is telling you.