Deena,

TKD is a beautiful art, great lower body work out. The focus is on kicks it will help your flexibility, range of motion, it'll build what some call "explosive strength" and concentration. Most TKD classes are very aerobic too.

It's an Olympic sport, competition can be fun. It's all good for the bike. Good choice for off season training.

Take it for those reasons, enjoy, have fun.

I'm sure your teacher would join me in hoping you and your daughter never ever need to "use it" but continue to enjoy learning and grow in the art.