Hi Kim - I've no idea whether this is the best way, but in Workout Manager there's a 'workout' tab - it allows you to create a workout. You can chose between strength, crosstrain and cardio. I timed the bonus butt w/o and gave it a met value the same as Gym Style legs (thinking they were perhaps similar). I think it was 20 mins and 6.5.
HTH
Justine