Friends of Dr. Joan Ullyot say she is everthing an American woman should be: intellectually alive, professionally independent, physically sensuous, committed to social values and enough of a renegade to be charming and perky.

The sensuousness I'll have to imagine, but in a recent conversation with her I found the assessments of her other virtures to be accurate enough. If life happens to be all sunshine and warm glows for Ullyot at age 37, she gives thanks to nothing else but running.

In 1976, she ran third in the AAU woman's championship. Her time was 2 hours 51 minutes, only 14 minutes slower than the American record set by Kim Merritt.

Last Sunday's Atlanta women's marathon, with 17 of the world's top women marathoners in the field, Ullyot finished seventh.

Her book, "Women's Running," has sold 100,000 copies. That, and her columns in "Runner's World," has earned Ullyot a reputation as an ardent advocate of long distance running for women.

As with many in the pack, she is now training for next month's Boston Marathon. In returning to Boston, she will be covering old ground in antoher way. In 1961, she granduated Phi Beta Kappa from Wellesley and went on to earn a degree from Harvard Medical School. Currently, she is a staff physician at the Institute of Health Research in San Francisco.

Visiting Washington a few days ago - to serve as a transaltor for the lectures of the German-speaking Ernst van Askan, the internationally acclaimed coach and phsyiologist - Ullyot delighted in the spring weather by going out for a training run along the C&O Canal. She ran with a group from the Washington RunHers Club.

Running, along or in a group according to Ullyot is always a supreme pleasure. "If that sounds like hedonism, perhaps it is. There is physical pleasure in running. This is hard for a lot of people to understand, particularly the male mind. Most men have been trained in sports to be competitive. That means you have to be hurting or else it isn't worth it. Women don't have this mental block.

We didn't have the 'athletic pain ethic' drilled into us through competitive sports. We are able to understand that running is a sport of recreation, not a sport of competition."

Ullyot has had troubles with men and competition, beginning with her former husband, a surgeon. She says that one of the rasons for her divorce was that she transformed herself from a flabby, poky and heavy-smoking housewife-mother int a runner who could make tracks. "My husband became a bid threatened. He was a good runner in college, at the 440, who always figured that in our relationship running was going to be his natural superiority. Suddenly it wasn't."

In San Francisco, Ullyot is a physical fitness advisor with the city's fire department. She talks of "my boyfriend," a fireman wh has no desire to run marathons. her sedentary smokeater appears to be one of the few non-runners Ullyot prefers to be around.

"When I go to parties with runners," she says, "I have a much better time. I was at a party with 100 runners and I brought along my fireman. He was amazed at how friendly we all were. There was no obnoxiousness, no brawling. He couldn't get over everyone being able to get along so well. I thought it was normal."

The subject of normalcy get Ullyot to talking about fellow physicians. She tells of runners visiting doctors only to be told they are in wretched condition because their pulse rate is 410 beats a minute. Actually, Ullyot argues, the person's running has so conditioned the heart muscles that they need to work less than the nonrunner's.

Women's running, the boom within the running boom, is likely to grow, according to Ullyot. "It's not a craze and it's not a fad. Most fads are based on something unnatural, like hulahoops. The point about running is that it's most natural activity we have. We're getting back, especially women, to feeling natural with ourselves. The feeling has been buried."

As for the practical effects of running, Ullyot notes that she went from a lumpy size 14 to a trim 10 in a mater of months after she began running. "It is a sure beauty aid. What is healthy is also beautiful. You get a glow from the inside out."

As for sexuality, she states that "runners make better loves, everyone knows that."

Not quite. It would be enough if only nonrunners knew enough to leash their dogs and clear the beer cans from the paths. Ullyot, as most runners of fervor, wants to spread the faith. She finds it tagic that Americans take better care of their cars than their bodies. She sees hope that with an increasing number of gym teachers being runners that children will learn the pleasures of the sport early. She looks forward to the day the non-runner will be seen as the abnormal one.