When it comes to walking, few can keep up with Jim Heiring of the Athletic Attic Track Club. Heiring set an American record in the 25-kilometer race walk yesterday at Constitution Gardens on the Mall, completing the course in 1:50.38, to break the old mark by more than a second.

The race was part of The Athletic Congress' championship events, and attracted participants from some of the nation's top race walking clubs. In the women's division, raced at 20 kilometers, Susan Liers-Westerfield and Teresa Vaill from the Islander Track Club in New York pulled away from the rest of the field and finished less than a stride apart in 1:50.28.

Heiring, who averaged 7:06 per mile, needed an even pace, good strategy and a little luck to pass Ray Sharp, who led for most of the race. Heiring, a member of the 1980 Olympic Team, trailed by 50 yards entering the final lap of the 2.5 kilometer loop. But Sharp faltered, and Heiring passed him and won by less than a second.

Seventy-three walkers entered the race, including 24 women and a strong contingent from the Potomac Valley Seniors Track Club, part of the organizing group of the race.

Heiring, 27, is hoping to peak for this summer's Pan Am games and eventually the Olympic trials.

Unlike Hiering, and his former Olympic teammate Dan O'Conner, who finished third yesterday, Liers-Westefield and Vaill have no Olympics to anticipate. There are no women's walking races in the Olympics.