People who’ve never seen South End dancer Michela Mattens got a chance to see quite a performance from the 14-year-old ballet standout earlier this month.

Mattens was the youngest competitor during Race the Rock, the Whidbey Triathlon, last Saturday.

Competing in the mixed over 99 division, she was part of the Matten family team that included her mother, Diane, and father, David.

Michela Mattens took the swimming leg of the trialthon. She stroked to a 19:31 finish during the swimming leg of the trialthon, an impressive first-ever performance for an 85-pound ballet dancer.

Overall, the Mattens family finished second in their division, just 15 seconds behind the first-place team.

For Michela Mattens, it was her first trialthon. In previous race years, she was on the sidelines as part of the support team for her mom. Diane Mattens has been a team competitor for the two prior Race the Rock triathlons; she came in third last year in her age group.

When the suggestion popped up this year to race as a family, Michela Mattens, who will be a freshman this fall at South Whidbey High School, was up for the challenge.

“I thought I could do the swimming,” she recalled. But she wanted to make sure, so she went to Lone Lake for a test run.

“I had a little doubt,” Mattens said, adding that she wondered if she could do it. “I wanted to see if the water would scare me.”

The doubt didn’t last long, and she found out the distance was manageable when compared to an indoor swim.

“I surprised myself. It’s really only 36 laps in a pool,” she said.

Seeing Michela power through the water convinced her mother that her daughter was ready to try the “tri.”

“She convinced me she could do it,” Diane Mattens said.

Diane Mattens took over the 3.8-mile running leg of the race, and David Mattens, the 19.5-mile bicycling leg.

But that meant Michela wouldn’t be on the sidelines for support. So her two twin brothers, 13-year-olds Evan and Aren, became the cheering squad and were there at the finish to hand them water bottles.

Seeing their sister compete may mean a change in the team’s lineup someday.

“I kind of inspired them a little bit,” Michela said. “Maybe the three kids can do it next year. You never know.”

Even though she knew she could handle the swim, she was worried that she would get “clobbered” by other competitors during the half-mile swim.

It didn’t happen.

“After the first 10 strokes, that was pretty much out of my mind,” she said. “Then it was like, I can start swimming a little faster, have a little more competition.”

“I made sure I had my eye on her as long as I could,” her mother said. “And made sure they had safety kayaks out there.”

“She kept swimming and came on strong,” Diane Mattens added. “I’m very proud.”

Michela thought getting ready for the trialthon would be a good way to stay in shape for the upcoming dance season. She had been swimming anyway two to three times a week to keep fit.

Dancing is demanding work, said Michela, who just recently returned from the Joffrey “summer dance intensive” in San Antonio, Texas.

“Swimming is a nice complement to dancing,” Michela Mattens said.

“Dancing is not for fragile people,” she added. “It takes a lot of strength.”

Mattens has been dancing since she was 3.

Her next performance will be in the holiday production of the Whidbey Island Dance Theatre’s presentation of “The Nutcracker.”

She’s been in the show before, as a cousin, a snowflake, a fairy, a flower and a mermaid.

Although she enjoyed Race the Rock and is thinking of competing again, dancing is her first love.

“The performing part is definitely my favorite. I like to be on stage, and I like to perform for people, “ she said. “I always dance with my heart and let it out.”