I'd like to tell you a quick story about two girls, Jennifer and Rachel, and my education as a soccer coach.

I coached Jennifer three years before I coached Rachel. At the time I was an average parent coach, which is to say I knew some stuff about practice exercises and soccer tactics from the internet and coach training courses, but not much else. 

Late in her U11 year, Jennifer seemed to hit an athletic wall. She'd always been a valuable asset to the team - we called her "Coach" because she was such a vocal leader and had a high soccer IQ - but she suddenly seemed to be two steps slower than her teammates and was consistently getting beat by faster players during games.

"I don't know what's wrong with her," her dad said to me. "She's so out of shape. I'm trying to get her to do some extra running, but she's not that into it."

I didn't know what to say. She seemed to work hard in practice, but I didn't know what her eating or sleeping or exercise habits were away from the team, so I didn't feel qualified to give any advice. In her assessments, Jennifer got poor marks for fitness and was moved down a team the next year. She seemed to not be having fun and soon stopped playing altogether.

I didn't really think of her much until I coached Rachel. By this time I had done the research for the Beautiful Project and had spent a good deal of time talking to Dr. Kate Ackerman, the head of the Female Athlete Program at Boston Children's Hospital about young female athletes and the effects of puberty.

Watching Rachel in her U12 year was like deja vu. The girl who was once one of our team's fastest, strongest players seemed to be running in mud while everyone else was on grass. Forwards who she had always shut down were suddenly turning the corner on her.

"She's seems so slow," her dad said to me. "I don't know what to do. Is there any kind of extra training she should be doing?"

"Relax," I said. "Her body is changing. This is a phase. Don't make a big deal out of it. Just ride it out and she'll be fine."

I told him that Rachel's body geometry was changing due to her pre-puberty growth spurt. It would sort itself out, and in the meantime the important thing was to make sure she didn't get discouraged. Make sure she understands what's happening, I said, and use this time to work on her technical skills. 

Two years later, Rachel's old foot speed is back. With her polished technique, she's one of the top players in her age group. But most importantly she's still playing - and loving - playing the game and being an athlete.

A little knowledge is a wonderful thing.