Looking for Professional opinion please
SW 318/ CW 156/Surg's GW 170/ my GW 135
Not sure I’m 100% on what your friends are talking about "not safe", but…
I know Curves uses hydraulic resistance which usually doesn't cause as much soreness because there’s no negative or eccentric movement. That usually causes more soreness. But for general health, especially the way Curves is set up, it's probably better to do the full Curves circuit say 3 days a week, like on Monday, Wednesday and Friday. Then do your bike 3 or 4 alternate days like Tuesday, Thursday and Saturday. Maybe take a break on Sunday or go for a nice walk around the mall.
If you like, since you’re in town, email me and I’ll send you my number and a good time to call. Maybe I can explain it better over the phone.
Good luck
Earl