"I DID a little jogging this morning," says Rep. John Conyers (D-Mich.). "I stay in good shape."

The test of that claim will be Sunday morning's Jog for Jazz, to be led by Conyers. The 6.2 mile race, a benefit for the nonprofit Charlin Jazz Society, will begin at 8 a.m. at Hains Point in East Potomac Park in Southwest Washington.

Conyers admits to being a "health buff" and that explains, in part, his participation in this event. But the biggest part of his support for the fundraiser comes from his lifelong devotion to jazz and his conviction that jazz musicians are "people who are incredibly gifted and who have made an enormous contribution for which they have not only never been recognized but have come nowhere close to it."

Conyers, who grew up in Detroit, said he was raised in a house that "didn't even have a record player." But Conyers didn't have to look far for music: The Detroit of the 1940s was a hothouse of jazz.

"Let me call off the names of the people I grew up with," he begins. "Ron Carter, Paul Chambers, Yusef Lateef, Milt Jackson, Tommy Flanagan, Kenny Burrell."

That was in his high school years, and later, in the Army, he fell in with fellow Detroiters Roland Hanna and Lucky Thompson. Older contemporaries were Howard McGhee and Rudy Rutherford. "Becky Carter was hanging around the Northwestern High School Band--she was carrying a saxophone."

In his early teens Conyers was checking out his aunt's 78 rpm records--Nat King Cole, Lester Young and Billy Eckstine--and playing cornet in the school band and a neighborhood jazz combo.

"The record that really blew my mind was Miles Davis' and Charlie Parker's 'Now's the Time' and 'Billie's Bounce,' " he recalls. He pins down the first time he saw Parker. "I was in a nightclub underage. He came to Detroit and we just had to see him, I mean, that was it."

Conyers was not motivated toward a career in jazz, since he was "spread out into sports and interested in so many other things." But he picked up the bass in the Army in the early 1950s and later "went through tenor saxophone and piano."

The role that jazz plays in the lives of black Americans is a continuing concern of Conyers. He muses over an event of some four decades ago, when clarinetist Rudy Rutherford won a poll in a jazz magazine.

"I used to hear him practice, going all the way back to grade school," he says. "We were so proud of him, it was like Jackie Robinson breaking into the big leagues. These were our cultural heros, the jazz people. Outside of sports it was the one thing a black person could look to with some pride."

During the '40s, when Conyers was discovering jazz, "they were talking about a new music, a new expression. There were lively discussions and debates about its validity and how long it would last. The whole idea was you could concentrate on these jazz heroes."

Conyers keeps a bass in his office in the Rayburn Building and "every now and then some of the guys come in and I immediately lock the door," he laughs. "So that nobody can tell when I'm playing and when they're playing. We always have a little fun."

Those jams represent one side of Conyers' ongoing relationship to jazz. But his commitment to the music does not stop there. In the late '70s he hosted a radio show of recorded jazz and interviews on WPFW-FM, a station he describes as "incredibly important as a focal point for extending the understanding" of jazz.

In addition he is a member of the advisory board of the Charlin Jazz Society, which has become a leading force in propagating jazz in the Washington area. Conyers is also the organizer of the Parker-Coltrane PAC, a consortium of groups and individuals concerned with training blacks in fund raising, organization and projecting their ideas.

"My feeling is that our cultural roots really transfer into the rest of our lives," Conyers sums up. "Including the way we regulate ourselves, how we govern ourselves. I've always been concerned about the musician as an outcast or as an unusual figure in our community, when actually he is the basic figure. With a very limited exception the existence of these musicians is one that's marked with great sacrifice and a certain amount of suffering. They're somehow supposed to exist and sustain themselves in a society which is basically technological and anti-cultural. So my concern, as one who is now a part of this system, is not to forget that."

Advance registration for the Jog for Jazz is today, 4 p.m. to 7 p.m. at the District Building. For more information, call 484-1697.