Knitting lowers blood pressure and so does crocheting; since my blood pressure is always low that doesn't matter much to me, but the process relaxes me and induces a bit of serenity, so I consider it a Wellness Exercise.
Here are some links that support the Knitting/BP/Wellness Connection:
Knitting Could Alleviate Major Trauma Effects,
KFLBP (knitting for lower blood pressure,
and I LOVE this one - A Novel Prescription for Knitted Brows, an MSNBC.com article with a picture of a man who had been laid off taking a knitting lesson as a coping mechanism.
Maybe these activities that should be covered by health insurance. Knitting needles and yarn could be written off.