Luckily, at least one other person on the internet is obsessed with squats as me, and he knows something about physiology. That would be Bryan Ausinheiler, a physical therapist in California who has penned a series of blog posts about the deep squat. “The squat is a great model for a multi-segmental movement pattern,” Ausinheiler rattled off at the beginning of our phone call. Uh, what does that mean? “The squat is a triple flexion movement. You’ve got bending at the hips, knees, and ankle, so you have to fold everything up underneath you.” There’s a lot going on.

But the key factor seems to be ankle flexibility. In the words of our editor Ross Andersen, “squatting makes me feel like I might rupture my Achilles.” A 2009 study in Japan found that men who found it impossible to deep squat had particularly inflexible ankles. This is also in part, Ausinheiler says, why kids have no problem squatting. “I measured my daughter’s ankle flexibility when she was one day old,” says Ausinheiler. “She has 70 degrees of ankle dorsiflexion! Normal in the West is like 30.” So humans are born squatters; some of us lose it when we stop trying.