Interval training on bike

Hi everyone,
I am a runner who struggles with hamstring injury at the moment. I am still able to do slower runs but can’t do my interval workouts, which tends to be repeated 400 metres with 45 seconds rest. My question is how can I perform exercise with similar benefits on bike?
Being mostly runner, I don’t have power meter on my MTB, using it so far only for Zone 2 rides (assesed by HR). Prefered way for me would be to do this exercise on hilly terrain…
Thanks for any feedback,
Luke