I try to be as fit as possible at my age but I don't hate myself enough to ever do that. Sorry, RP.
One of my workouts is a combined HIIT + weight/strength, the latter part being moderate weight with high reps, it alternates between very intense cardio with little-to-no rest between spikes, and strength (some body weight based, i.e., pushup variants and dips), so we might do 6 sets of 8-10 cleans, wide-ups, squat presses, all fast, some pulse and iso type work, then sections of more pure cardio.