Aerobic vs Anaerobic - For Rugby

Hi,

I am a rugby player for the local team, nothing too serious but I want to
improve my stamina and speed the best I can.

What I really need is some advice on the kind of fitness training I should
be doing. Rugby requires a lot of stamina, because you are always on the
move running backwards and forwards, but does also require some high speed
bursts and quick recovery.

At the moment I am doing 1hr a night on an exercise bike using a heart rate
monitor controlled program (Am 32 years old, weight 96kg, set HR to 155). I
also am doing interval training on a stepper machine to try and increase my
quick burst and recovery.

I am also keen to increase my general speed.

Does anyone have some advice for me?

Steve