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.