Running should come naturally. Many of our faults of style come from the way we grew up and what impresses us. When I worked at the Y in Rome, N.Y., I coached a youth track team. One regular event for our kids was a mile run. It was the first exposture to distance running for most of them. Rather than teach them how to run, I decided just to let them run naturally and then work on apparent faults in form. The top runners of the future aren't necessarily the fastest, but those with an economical stride, patience and willpower. Form counts more than time when you're young.

I was amazed by the difference between the boys and girls. The majority of the girls ran smoothly and gracefully with near perfection form. In fact, many of them ran faster over the mile than the boys. The boys, however, tended to run like football of basketball players. Physical education in the "ball sports" emphasizes this style, which promotes power and speed.Therefore, many boys learn to run high on their toes and have a pronounced upper-body movement. Competitiveness, learned from an early age and reinforced with Little League baseball and Pop Warner football, is reflected in their tense bodies. Sitting before the television set, watching football, and basketball heros, reinforces the running form of power-speed athletics. The girls, however, aren't exposed as much to highly competitive "ball sport" activities, and instead participate in sports that emphasize form, agility and patience, like gymnastics and dance. A ten-year-old girl probably the most natural runner in our running world.

We face a relearning process when we wish to "run for fitness." How can you teach running form? It can be detailed on paper, but I highly recommend that beginner runners start by running naturally, under the watchful eye of someone who can correct obvious faults in running style before they become bad, hard-to-break habits.

Running, when done properly, is a complete, flowing action that takes place unconsciously. The following analyzes parts of this fluid movement, and will help you check your own style, or that of a friend. FOOTSTRIKE AND STRIDE

All runners land first on the outside edge of the foot, and roll inward as the rolling action cushions the blow. Sprinters contact the ground high on the ball of the foot. Middle-distance runners hit on the metatarsal arch. long-distance runners and joggers strike heel first. Some distance runners hit somewhere between heel first and ball first, landing on the outer edge of the whole foot. Some coaches, including Pete Schuder, Columbia University track coach, teach this method of footstrike.

Running on the toes produces more speed and power for short distances, but in longer runs, it results in leg fatigue, calf tightness, shin splints and Achilles tendonitis, among other maladies. Many joggers run with a slow "flat-foot" technique: The entire foot strikes the ground at the same time. The wide surface area cushions this footstrike, and it's easy on the rest of the body. It is difficult, however, to run very fast or for long periods of time with this style.

Proper footstrike for the long-distance runner and jogger is important. The foot contact should be as light and silent as possible. The foot should strike the ground on the outside, betweenn the heel and the metatarsal arch, and, on contact, gently roll forward and inward to the ball of the foot, and then gently upward and outward to toe-off. The toes should be pointed straight forward, but don't force this if it's uncomfortable.

The individual components of stride are length, knee-lift and back-kick. The faster you go, the more you increase the length of your stride and your knee-lift and back-kick. The point of foot contact should be directly in line with the knee, with the knee sligtly flexed. Actually, the foot should hit the ground after it has stretched forward and has already started to swing back. If you overstride so that the leg hits the ground ahead of the knee flex - the leg is straight - the result will be braking action rather than forward propulsion. A short, choppy stride is also inefficient because more energy is used travelling a shorter distance. Runners with pronounced knee-lift or back-kick (other than in short sprints) are merely wasting energy. RUNNING POSTURE

Bill Bowerman, former track coach at the University of Oregon, feels that an erect posture is most essential for a smooth running style. "Run tall," he preaches to his disciples, with your back as straight as naturally comfortable, the head up and eyes straight ahead. An imaginary line drawn from the top of the head through the shoulders and hips to the ground would be perpendicular.

A forward lean places an extra burden on the leg muscles and often contributes to back pain and shin splints. It should only be used when sprinting or going uphill. Leaning backwards has a braking effect; it places a severe burden on the legs and back.

The shoulders should "hang" in a relaxed manner, level to the ground. Concentrate on not allowing the shoulder blades to pinch together. Be aware of tension beginning at the base of the neck, in the jaw muscles, around the eyes, in the muscles of the forehead and in the shoulders. Occasionally, let the head roll from side to side, shrug the shoulders and let them drop, or drop your arms loosely at your sides to promote relaxation. BREATHING

Many runners ask, "How should I breath while running?" or "Should I breathe with my mouth open?" There is a theory that runners shouls breathe in through the nose and out through the mouth. Supposedly this promotes relaxation and filters the air. But running calls for a lot of air to satisfy the body's need for oxygen. You won't last long breathing in through the nose and out the mouth. Open up your mouth and suck in all the air you need.

Some runners enjoy breathing in tune to their footstrike. They may inhale, for example, on every other left step, and exhale on every other right. Such breathing techniques may be relaxing during yoga exercises, but they would drive me nuts during a run, and I'm sure I'd get confused. If I had to blow my nose during the run, would it count as exhaling? What if I sneezed when I was due to inhale? Life is too short, and running too beautiful, to spoil with rigid rules. My advice is to breathe when you feel like breathing, following "belly breathing" principles - the belly expands as you breathe in and flattens as you breathe out. THE THREE Rs OF RUNNING STYLE

Run tall.

Run relaxed.

Run naturally.

For the most part, you are born with a certain style that changes as you do. The best we can hope to do is to clean up bad habits. "Natural" runners possess a beauty most of us who can recognize, a partially imitate. Study the mechanics of a proper running style, but always be yourself.