Hiya yellow fang, cycling is good for us in so many ways but yes its not a weight bearing exercise. Yes standing on your pedals can help, or creating more resistance with your gears but you've got to watch your knees. I follow coach Levi and my local gym also advised me to do body pump, I had lots of lean muscle but due to the lack of weight bearing exercise I had lost skeletal muscle, thankfully it didn't take that long to right it (with body pump and pushing my self on the hills)! If you don't fancy cross training with weights try running, there's lots of free apps that will help you follow a plan so you don't injure your self like run keeper.