setting starting rates is always difficult. In all probability, you will have to go a little lower than the market rate because you do not have man clients yet to use as a reference.
I looked at your profile and noticed that you have not yet a liability insurance posted. Since I gather from your information that you plan to go to people’s homes, this is mandatory.
However, I read your blog which contains your own fitness personal story. I would use this as a selling point and contact organizations like the Arthritis Foundation or Weight Watchers to see whether this will get your foot into the door with a clientele that can relate to you. As Calvin said, we cannot be anything to all people. Once you find a good niche, it will be easier to set rates that reflect your competitive advantage.