If you are not tall, you should be strong. If you are not strong, you should be healthy.

00 * * * * Hand in hand, keep fit and shape, persevere, you and I walk together.

Note: the location of * * * can be changed to the name of the gym. The content and rhyme of this slogan are ok, but it is not concise enough. I don't know what effect you need. You can modify it yourself as needed. For reference only!

If you need help, please ask! I hope the answer will help you!