Stationary bike?

yahmd

I own a stationary bike and I will generally work hard for an hour and sweat a lot. My heartbeat doesn't go up like crazy ( like when I go running) but I still feel good after. Is it helping? I've also noticed that my legs are getting more muscular and bulking up. I don't know if I'm happy about that or not! What do you guys think?

Should I just buy an elliptical or something?