I joined here about two months ago by posting "New SCS recipient, want to stay active." Time to post an update with some answers. I have been
mountain biking twice a week for 23 - 30 miles at a time. The first time I went out I hurt so much I seriously considered quitting biking. Perhaps I became too soft after two months of virtually no pain. I've since dialed up the SCS and I also take some pain medication before riding. I'm not pain free but it isn't too bad. However, I do feel pain for the next several days. So I will have to decide on an acceptable level of pain vs. not riding at all. I have also already fallen off the bike twice, so far with no adverse effects.
I just started back lifting weights last week. I do mostly seated machines and free weights with my back supported. Due to the positional shifts while lifting, e.g. in overhead movements and straightening my back, I have to turn the SCS so low I can barley feel it. Otherwise I get a pretty good jolt.
I'm still cautiously deciding how much I can do with this SCS.