A whistle shrills across the soccer field and the first half ends. The players, dragging a bit at the heels, dutifully troop off to the sidelines. Mike, who's huffing and puffing and gulping for air, turns to a teammate, who's flushed and sweating profusely, and asks, "Why are we doing this, Gunther?"

There is no time for an answer. Gunther, Mike and the rest of the Bethesda soccer team players, an 18-man squad, need to spend half time catching their breath, resting their legs, sucking oranges and discussing strategy. Bethesda is losing to Old Red, 2-0, on a beautiful Sunday afternoon at Kensington Junior High School, and there's no lack of suggestions from the players on how to turn the game around.

But Mike's question hangs in the air as the Bethesda boys of summer -- the youngest is 35, the oldest, 58 -- prepare to take to the field again in what's considered, with good reason, to be a young person's game. Playing two 45-minute halves on a regulation 110-yard field, a soccer player logs between seven and ten miles of running per game. And, the wheeling and spinning of the body to save the ball from going out of bounds, the sticking out of a leg or foot to steal the ball from an opposing player, the use of the head to steer a high ball in another direction are the stuff of which broken bones, sore tendons, and stressed ligaments are made. When you're over 35, those bones and tendons and ligaments tend to heal not so fast nor fully.

"I play because I love the game," says Calvin Yowell, who, Monday through Friday, is an executive with IBM. On Sunday, he's Bethesda's starting forward. "I played in the Montgomery County open league for years, but when you're in your 40s, you don't have the stamina to keep up with 21 and 22 year olds. This league makes it possible to keep playing competitively."

John Montgomery, who played soccer in high school and gave it up for football in college, now makes his living as a lawyer but gets his kicks on the soccer field. "My initial reaction when a friend invited me to play in this league was, I can't. But once y ou get out here, you realize it's more of a fun thing than cutting-edge competition. The majority of the players have better skills than I do, but when you're over 35 it evens out a little bit."

One of the "babies" of the team, Stu Pearson, 36, didn't start his soccer-playing career until he was 35. "I was coaching my kid's soccer team, and I decided I'd be a better coach if i tried playing it myself.

"It's not as easy to do things on the field as it looks. I've learned more about field position and how to play to open spaces, but it's hard, when you're 36, to learn ball handling and to get over your fear of getting hurt on a head ball. But it's fantastic and more fun than jogging. It's a great way to keep in shape."

Does he worry about getting hurt? "It's like skiing," says Pearson. "I you worry about breaking a leg, you will."

Alex Herschaft, who is 45 and has been playing soccer since he was 11 years old and living in Italy, doesn't fear pain so much as he knows about it. "I played through college and graduate school, in industrial leagues and then in the county's open league. When I was 40 I started getting hurt a lot in the open league; it took me a long time to heal. Now I'm 45, and it's better to play with people my age who have more respect for each other and who know you have to go back to work on Monday."

Not that things don't get rough on the fields of play. One 44-year old congressional aide, who prefers to remain anonymous, says he played in a game last year where the other team banged into him, knocked him down, "were really rough. My heel was sore for three months from the beating. After the game, one of the players came over to me, shook my hand and said, 'No hard feelings. I though you knew, we always foul when the ref's not looking.'"

From the vantage point of ten years of referee experience in over-35, open and co-ed soccer leagues, referee Cliff Elkins says, "The older players are more tentative, but the skills are there. The single biggest problem in the over-35 game is that some of the players are not good sports."

Another ref was blunter. "They're worse than the nine year olds."

Jim Wiltshire, sports coordinator for Montgomery County Department of Recreation, says players have been disciplined for being too rough and causing injuries. In an effort to take the edge off the competition and improve sportsmanship among the senior players, Wiltshire stopped awarding trophies to the winning over-35 team and changed the championship honorarium to paper certificates.

The over-35 soccer league was the brainchild of Alex Herschaft, who suggested the idea to Jim Wiltshire four years ago when they were playing vollyball together in another county program. Wiltshire liked the idea, advertised it in the paper and came up with 43 interested players.

"Our first season in the spring of 1976, we just had the players show up, choose sides and play. By the fall, we had enough players to organize the league into four teams. Now we have 12 teams with 18 players apiece. I was surprised at the rapid growth and the improvement in the quality of play. I wouldn't be surprised if we start an over-50 soccer league one day."

Each over-35 team pays a $260 franchise fee for a season's play, spring or fall. The players chip in to pay the fee which covers the cost of referees, field supervisor and certificate awards. If the fee is divided equally among 18 players, it comes to about $2 per man per game.

The season has 11 games. Unlike youth team leagues, over-35 has no rules about how much time each player must play; nor is the playing field size or playing time cut to suit the age of the players.

"We're just like the pros," Yowell says, "only we don't get paid, we don't draw a crowd, and we're not as good."

During the second half of the Bethesda-Old Red game, Yowell's point is hammered home. The half gets under way with a power play.The ball comes squirting out of the middle and is whipped and kicked and bounced and passed between Bethesda players (white shirts, red shorts). Old Reds (red shirts, white shorts) try to break the rhythm, take the ball away. With a sudden burst of speed, a white-shirted forward outruns a red-shirted fullback and kicks the ball across the Old Red goal mouth. There his teammate puts cleated shoe to the black-and-white ball and boots it toward the goal.

Old Red's goalie -- receding hair, overweight midriff, 48 years of living well -- makes a desperation play, flinging his body up and sideways to block the ball. For one spectacular moment he hangs suspended, above the ground but parallel to it, floating in space.

The effort comes to naught. A second later he lies crumpled on the ground, the ball nestled in the goal behind him.

It's a short-lived rally for Bethesda. They will not score again on this particular Sunday afternoon.

But after the game, they gather together under one of the trees, break out the beer, replay the game in reverie. A wife or two wanders over; so does a handful of kids. What with the beer, the team camaraderie, family support and the exhaustion of playing a game, the Bethesda over-35 players feel like young athletes again. And that's partly what brings them back for another bruising game the next Sunday.

And here's a mere sampling of other play:

Fairfax County soccer for men over 30 takes place at 4 on Saturday at these locations: Idlewood Park in Vienna; Floris School, Herndon; Kincheloe Road, Clifton Village; Great Falls School, and Braddock Road Elementary.

Women's teams (over 31) will play noon Sunday at Thomas Jefferson Intermediate School, Glebe Road and Route 50.

To see younger players, midget teams -- 5th and 6th graders from the Montgomery County Recreation Department -- will play Saturday at 9, 10 and 11 at the Georgetown Hill Elementary School, 11614 Seven Locks Road, Rockville. The Arlington Aardvarks, a team of boys born in 1964, has one of the best win-lose records in the country, with 104 wins in the last two and a half years. To find out where the next games are, call John Verstandig, 244-1422.

And if you want to catch the game at the pro level this weekend, the Dips play the New York Cosmos Sunday at 2 in RFK Stadium.