Despite all the technological advances in running shoes, the enormous amount of written material on the subject and the use of sophisticated computerized training programs, most people who participate in distance running still get hurt.

Why? Primarily because they go too far, too fast, too soon.

Many new runners are in great shape from a cardiovascular standpoint. They may be regularly involved in other sports, such as swimming, cycling, racquet ball or tennis. But that isn't the same thing as your foot striking the ground 1,000 times a mile. And if your feet and legs are not given a chance to adjust gradually, you are headed for trouble.

To increase physical ability -- no matter what sport and at what level -- it is important to push yourself periodically. However, this must be done gradually to build up the body rather than break it down. Thus, the first rule to keep in mind is to push yourself gently.

Next, be sure you are consistent with your training so you continually increase your ability and endurance levels.

Set down your own carefully planned schedule of realistically attainable goals. Make sure you give yourself enough time to reach them so that you can give yourself a pat on the back and gain confidence to keep on running.

Otherwise, you will get discouraged, stale or injured, and you may never reap the benefits of running. Getting a Good Start

Any beginning runner should be aware that the initial phases of running, as with other new physical activities, will be accompanied by various aches and pains. Often a good deal of will power and self-discipline will be needed to stick with it.

The more sedentary an existance you have led, the greater the effort that will be needed. There will be days in the beginning when your feet and legs will feel like lead weights. Then, after a day or week of great progress, you will have a day when you will run one block or a half mile and feel you cannot go any further.

But don't quit. You must be willing to give yourself at least six months for your body to become accustomed to running and to absorb its positive effects. Then you will be hooked.

There are, however, some precautions the beginning runner should observe.

If you are 35 or older, you should consult your physician before starting on a running program. If there is a history of heart disease in your family, you should have a physical. Some experts also recommend a stress test electrocardiogram. This is a heart test administered under physically stressful conditions to evaluate your cardiovascular system.

If you have asthma, diabetes or any other chronic debilitating disease, consult your physician before beginning a running program, no matter what age you are.

It is important to start off slowly -- not only to give your body a chance to adapt, but also as a means of preventing injuries.

To increase cardiovascular fitness, it is necessary to exercise at least 20 to 30 minutes, three to four times a week. During these workouts, the heart rate should be elevated to between 70 percent and 85 percent of its maximum.

To determine your maximum heart rate, subtract your age from 220. For example, if you are 30, your maximum heart rate would be 190. A hard workout would elevate your pulse rate to between 133 and 162 beats per minute.

For people who have had debilitating disease, are overweight, or have led a sedentary life style for a prolonged period of time, a 60 to 70 percent elevated heart rate is more appropriate.

You should not train hard more than three days a week and never two days in a row, no matter how many sports you participate in. It takes 24 to 48 hours for the muscles in the body to recuperate from a hard workout. This is a cardinal rule of training.

Always warm up for a few minutes by running or jogging at a slower than average pace. Then stop and stretch slowly for about 10 minutes. It's important to stretch the muscle groups in the back of the body daily, since they are used extensively in running.

After running, you should cool down by slowing your pace for a few minutes before stopping and stretching carefully again.

During your runs, you should be relaxed and move at a comfortable pace most of the time. This means you should be able to talk to yourself or to a partner without being out of breath. You should feel refreshed after the majority of your runs, not exhausted or wiped out. Improving Performance

Never try to increase distance and speed at the same time.

It is usually preferable to increase distance first. To increase distance, build up by 10 percent of your past week's total distance every two to four weeks. For example, say you have worked your way up gradually to 20 miles a week. To increase, do 22 miles a week for two to four weeks before going on to another plateau.

To improve your pace, take 20 to 25 percent of your total weekly mileage and speed up by five to 15 seconds per mile for that portion of your run. Do this for two to four weeks, then take another 25 percent of your mileage until you have worked on all of the miles that you wish to run faster.

Develop good form. Run with your body completely relaxed, using a smooth and gentle stride at a comfortable pace, keeping your body erect. Your head, shoulders, chest, hips and legs should be in a line. Land gently with your weight on the outside of your heel. This method of landing transfers your weight along the outside border of the foot to the big toe for a forceful propulsion.

Running on the ball of your feet for long distances is not good and often leads to injury. If landing on your heels is difficult, then land flat-footed.

Your stride should be of a comfortable length. Lengthening your stride in an effort to increase your speed will lead only to overstriding and straining yourself. Overstriding can lead to knee and other injuries. Signs of Overtraining

There are many signs that someone is overtrained, coming close to overdoing it, and thus susceptible to injury. Some of the more common ones are:

* A sudden loss of desire to run.

* Nagging aches and persistent pains in various muscles.

* Feeling unusually tired or fatigued after a run.

* Insomnia, problems falling asleep or unusual struggle to get out of bed in the morning.

* Headaches, frequent colds or symptoms of the flu, though no fever is present.

* Recurrent fever blisters on the lips.

* In women, menstrual irregularities.

* Constipation, diarrhea.

In addition to these, you can check for other physical signs that may indicate overtraining.

For example, after waking up in the morning, rest in bed for a moment or two. Take your pulse; after two weeks, you will have your average daily pulse. On a given morning if your pulse is seven to 10 beats higher than your average, then you are either overtrained, getting ill or perhaps have a reason to be emotionally upset or excited.

If emotional distress can be ruled out as a cause, then consider an easy run, or a shorter one, or do not run at all. Any running, especially a hard one, could easily lead to injury.

Cut back or take it easy until your pulse rate returns to normal.

Sleeping habits are also important when it comes to training.

If you have to work longer hours or are under excessive emotional stress and do not get enough sleep or rest because of this, then you are more susceptible to injury if you continue to run at your regular pace.

Unexpected weight loss can mean your body is overworked and undernourished, and the resulting fatigue can lead to an injury. One study showed that a two- to three-pound weight loss in one day, or a marked increase in fluid intake, are likely to lead to injury in a few days if you continue at your regular pace. This is especially true during warm weather.

Another sign of overtraining is urine color. Urine should be clear and odor free. In an over-stressed, dehydrated runner, it will be a darker shade and perhaps be accompanied by an odor. Occasionally, blood may be present. If you have these symptoms, contact your doctor.