Hi
I have been running my own small (just me!!) graphic design studio for nearly 15 years and you will receive a professional, reliable and experienced service if you choose me to produce your fitness flier.
I guess the predominant colour would be the orange of your logo, the circles could also be used in the design, I can source a good healthy, fun, picture.
If my first design isn't exactly what you are looking for I would allow endless revisions until you are happy with the design.
I hope this is of interest to you
regards
Clive Davies