Given Marc's huge topic about afterburn of resistance training and efficacy of HIIT cardio, I'd like to indicate that Bikram yoga (and possibly other kinds I haven't attempted) includes a good deal of strength training (
mostly the largest muscles i.e. legs, core and lower back with upper body coming as you go heavier) and feels pretty much like a
high intensity cardio work out
for perhaps 60 - 70 of the 90 minutes — as well as the other advantages.