You are right, online reported numbers aren't accurate. I myself train in a heavy high intensity strength training cum powerlifting cum bodybuilding style.

And if my fitness watch is to be believed, my workouts burn anywhere between 600 to 1000 calories.

But 2.5 hour long exhausting workouts aren't everyone's cup of tea. For most, "working out" refers to a normal medium intensity weight training session.

And the point here was spot reduction. Sure, a few heavy sets of back squats can torch calories and burn fat but crunches aren't likely to