Running can be bad for your knees so I can see you wouldn't want to go down that road.
With a bike though, it's difficult to get the intensity up.
If you're going for endurance and marathon-like rides, then more power to you. But if you want to do HIIT, I don't see how that would work. Every time you go full-out, you'd end up going too fast and have to slow down. Better to do burpees, or maybe swim?
If you really want to do bike cardio, it would be best to use a stationary bike so you can do "sprints" and not worry about how fast you're going.
I'm looking for some extra stamina towards the end of pickup hockey. They have stationary bikes at the gym where I train, but a real bike might be nice too. There are lots of hills around here so getting my heart rate up shouldn't be a problem.
If you're looking for stamina and cardio with a bike you have to focus on your pedal rate more so than your bike speed. You need to keep your pedal speed up at a consistent rate in the 60's to 70's when you're riding, uphill or on the flats. If you ride the back roads, a crossover might be the bike for you unless your roads are in pretty good shape.
If you want to truly train for hockey then I'd recommend using a stationary bike.
If you want a bike to ride around for fun while working your leg muscles and spending time outdoors, I'd recommend a hybrid. On one hand there's no point getting a full on mountain bike if you're never going to go off-road, but on the other hand there's no point in getting one of those dinky (but surprisingly expensive) street bikes unless you're in an urban environment.
I have a hybrid and I usually stick to the main/side roads, but I occasionally feel the temptation to cut across a hydo field!
try a hybrid bike or cross bike. they usually are set up like a mountain bike with skinnier tires and the ride a little smoother than a road bike. bicycles are excellent for training for hockey, chelios is an avid mountain biker. as far as your pedal rpm (called cadence) wear a heart rate monitor thats what you need to pay attention to. you guys that are saying ride the stationary they dont count pedal strokes its all about the heart rate. all the spinner classes and the like are designed to mimick real rides. be forewarned your butt is gonna hurt for a week or 2.