Welcome to the blog @BernieWal - sorry to see you join our select little group. :( I was your age when diagnosed!
Ask away any questions & we'll do our best to answer them ... well done on your surgery & wishing you all the best with your chemo. (I dodged that bullet, with lumpectomy, clear margins, not in the nodes) and then 4 weeks radiation & now hormone tablets.
Wishing you all the best - definitely, keep up your running/exercising, but also listen to your body too, as the chemo may knock you around a bit. (Have a think about 'running in the pool' if you may not be able to hit the roads! ;) ) It is kinder on your body. ;)
Take care