Airdyne Workout-Help??

There is an airdyne bike at my gym and I've heard they are great for anaerobic and aerobic conditioning. However, there is no resistance on it and even when I peddle like a madman I don't feel like I'm getting much out of it (compared to how an elliptical wears me out)

Can someone give me an idea of the type(s) of workout you can do on it as I really want to put it to good use! thank you

I do Taku's Intervals on mine and they're intense.

Maybe your airdyne is busted? That bike is designed so that the harder/faster you pedal, the higher the resistence you get back.

Try doing intervals where you alternate between using arms only, and
using both arms and legs. Gets very tough very quick.