So, time to be a nerd. Watching this helps me realize that sex really does take a large amount of energy to perform, no wonder it can sometimes substitute a workout for the person on top. And this isn't exactly a slow pace either, that guy is able to consistently slap his hips against her ass. Sure, it only goes for about a minute and 30 seconds, but most workouts have you take breaks in between 2-minute exercises anyways? And if he's able to go for a couple more rounds, he'd easily be able to pass the infamous 5 minute mark of pure sex, not counting the breaks in between.
And yes I realize this is an animation, but this is a much more realistic standard for sex than almost anything on Pornhub without the amateur tag :)
