Hi Cheryl, what I've learnt is Arimidex and all the AIs affect everyone differently. For me I had a lot of hand, knee and feet joint pain, wasn't sleeping very well and very tired. I kept up the exercise as much as possible, just half hour walking, trying to get a bit puffed, so not a gentle stroll. This helps in the short term, but I found my knee pain was getting quite bad from that. Panadol & neurofen helped, again short term. I'm 2 days into exemastane, so am keeping an open mind about how this will go...Hopefully you'll have zero side effects, but if you have some, talk to your oncologist, there are a few options out there if arimidex isn't for you...