Any aerobic exercise should help your cycling. However, it will only help a certain amount.
I once suggested to a friend that we ride together sometime. When I did, I could tell that he thought that I was big and fat and out of shape. I was a bit over weight but not much. He had just done the Boston Marathon. Well, I had just done about 6000 miles in 3 months. So I had absolutely no problem out climbing him on hills or just motoring away. Any exercise is amazingly specific.
But any exercise beats no exercise by a very wide margin.