SACO — If you drop by Thornton Academy during an afternoon this fall, good luck finding a place to park anywhere near an athletic field.

Thornton had its largest ever sign-up for fall sports this year, with 555 students registering in total.

As of Wednesday morning that number stands at 436 holding roster spots, Thornton Athletic Director Gary Stevens said that is an increase over the previous record of 425 a year ago, with the total expected to rise as international students move in this week.

The large participation numbers this fall only continues a trend at Thornton, with more than 700 student-athletes competing for the Golden Trojans last season.

At 1,384 students, according to 2012 enrollment numbers, the Trojans have the largest student body in Maine to draw from, but Stevens said the growth he’s seen in his department over the past few years has to do with more than just raw numbers.

“People do want to be part of successful organizations,” Stevens said. “You just look how fans are, people join the bandwagon and want to be a part of something that is seen as being successful. That’s just a natural human instinct, and we see it in the athletic program as well.”

A large part of that growth has been fueled by Thornton’s introduction of volleyball, which started play last season at the junior varsity level with more than 50 girls participating, forcing Stevens to split them into two teams.

The program has around 60 girls taking part this fall as it makes the move up to the varsity level, and Stevens said the introduction of volleyball at T.A. was “by far one of the best decisions I’ve ever made.”

“We’ve created an outlet for students who love that sport and are really passionate about that sport to pursue it, and we’ve had a number of students who have found a new passion,” he said.

“We’ve found by and large that participation in volleyball is not taking away from other (fall sports) programs. These are students who would not have been involved in anything at all, so it created another way for students to be involved in something active.”

It’s the same story across the bridge at Biddeford, where numbers are up in many fall sports, with 52 players out for football and both soccer programs reporting numbers in the high 40s.

Biddeford Athletic Director Dennis Walton said he believes the school’s emphasis on encouraging students to play sports in all three season’s is driving higher participation numbers, especially in smaller sports such as golf, where the Tigers have a record 26 students on the team this fall.

That emphasis on three-sport athletes started five years ago, when the school instituted the “Iron Tiger” program to encourage more participation across all three seasons.

As part of the program, every athlete who participates on three teams throughout the year receives a Tiger head trophy and an “Iron Tiger” T-shirt at the school’s spring sports assembly.

“That’s become a driving force behind kids playing three sports,” Walton said. “And where it really helps is kids who play two sports say, ”˜The heck with it, I can do one more season.’”

In the first year of the program Walton handed out 91 Tiger heads. This past spring, he gave out 146, a growth that he says is healthy both for the individual athletes and the school, which had an enrollment of 830 in 2012.

“First and foremost I think it’s the best thing for the kids,” Walton said. “We did a study a couple of years ago and it was overwhelming in that kids who participated in extra curricular activities tend to do better in school, tend to miss less school and tend to have fewer discipline referrals.

“But from a school standpoint, everybody knows that Biddeford is now one of the smallest Class A schools in the state. So we always emphasize to our kids that we have great athletes, but we need them to participate in three sports in order to stay competitive with much, much bigger schools.”

— Staff Writer Cameron Dunbar can be contacted at 282-1535, ext. 323.