Allen has grown rapidly as a teenager, but it's his attitude not his height that makes him tall in the water. His coach, Paul Silver, says he can't overwork this guy.
"Anything we give him," Paul Silver explains, "he says it's fun. We give him eight miles to swim, and he says it's fun and has a blast doing it."
"I always say it's fun," Allen admits. "Sometimes it's a little borderline whether it's really fun or not. But if I tell myself it's fun, that helps sometimes."
Paul Silver is not known for easy workouts. But it seems like the more yardage he piles on, the more Allen thrives on it. He remembers one really hard day last year.
"Sixty-two hundred yards. Fast intervals. I could hardly do any of them," Allen recalls. "But it was a lot of fun though."
And later this summer, as one of the stars of a distance camp in Tennessee, Allen will work out at the USOCTC in Colorado Springs.
"I get to play with all their toys," Allen explains. "They have a flume there. They have a lot of computers and stuff to analyze your strokes."
Sounds like a lot of fun.