"It's a lot of short burst movements," she explains, pointing out the differences in sports. "You're running back and forth; it's not a long distance sprint. The difference is the ball comes back at you way faster from all directions. It's not coming right to you every time."
Johnston is playing doubles; her teammate isn't someone she's in class with. It's Superintendent Dr. Fred Czerwonka.
And according to Dr. Czerwonka, their team is undefeated.
"He's really good! I'm glad I'm on his team and I didn't have to return any of his serves or anything," Johnston said. "It was fun. He really showed us what a good racquetball player is and what we need to do to be better."
Dr. Czerwonka has agreed to play racquetball as part of a special, physical education class.
"My son, who's a junior at Central, we play racquetball together," he said. "We did all last year. We will again now that it's winter and you can't get outside as much. So I just love being around kids. That's why I'm in education."
Jeff Sullivan, or Coach Sully, teaches the Elite P.E. class at Central.
He's the one that gets the students out of the school gym and at the YMCA.
"Most of these kids are juniors and seniors," Sullivan said. "They're going to be going to college and they'll be going to facilities like this at a college, that have elliptical machines and things we can't offer at the school at Central."
Sullivan says the students in Elite P.E. can basically make their own workout program.
"If they want to use the treadmill or lift weights, or play racquetball, swim, volleyball, or basketball; [they can use] anything the YMCA has to offer."
Even though they're playing a game, Coach Sully says it tricks them into having a good workout.
"They come out of here sweating way more than they would riding the bike or the treadmill," Sullivan said. "They don't realize how much they're sprinting: even if it's just six or seven steps. They're starting and stopping and going back and forth and trying to avoid. It teaches them a lot of hand-eye coordination, getting out of the way, working well with others. There's a great benefit."