Do you know of any grants that would fund a community group fitness class?

The government grant site will not provide you what you are looking for because those grants are science based large scale funding, and take years to attain. The proposal itself could take ages.

The great thing is that you are a non profit, therefore you are eligible. You want to check grants given by corporations or associations. For example companies like cola cola, or the National Parks and Recs http://www.nrpa.org/achieve, or try http://www.aahperd.org/naspe/grants/grants/.

You also need to know how to write a grant for money.

Keep following threads to other potential association. Check with you local hospital. You may be able to piggyback or join forces on their community funding if they are non profit.

All the best,
Danielle