It’s free hosted by WordPress.com.
Or you can download the software from WordPress.org and post a blog on your own host.
The Gymblog linked to this “theme” (template) which would give you an impressive look.
Free WordPress Theme – Gymnastics
This theme cannot be used on WordPress.com, but can be used with self-hosted blogs.
(If this is all confusing, get a geek in your neighbourhood to explain it to you. Once set-up, blogs are not much more complicated than a diary.)
Gymnastics Coaching.com 