In reply to Fiona Reid:
Maybe stating the obvious, and everyone is different, but a basic, gentle Pilates class is doing me the world of good. I've been walking and running for 25+ years, and now (in my 50s), things are beginning to creak. Exercise tightens everything up, and if you do tightening up continually (I'm told the default action for muscles is to contract, so liken it to perpetually turning the screw), you can guess where that ends up. I've started attending a gentle regular Pilates, and am feeling the benefit of moving (which increases blood flow which helps) and stretching (reverse of the default contracting) muscles which I never knew I had, had forgotten about, needed "un-tightening", and generally moving. Walking and cycling tend to keep upperbody in one position (think about being strapped into a rucksack, or sat on a bike) in a repetive similar movement, so it's good to get out of that mould.
It's working for me at the moment, other people may think differently, and have other needs and need specialist advice. And looking on the bright side, my Pilates class is me and 10 lovely ladies once a week getting sweaty If you pick your Pilates class and tutor carefully, they should be able to assist with any injuries or niggles you need taking into account: the training for some Pilates qualification can be quite rigourous.