Core strength is vital in almost everything we do — from sitting up straight at our desks to maxing out our deadlift. A weak core could mean serious plateaus in the gym, and even an increased likelihood of injury. Is your core as strong as you think it is? Kris Clever has one way to find out. This core strength exercise tests your arch and hollow positions, and it looks ridiculously hard. Athlete Jamie Hagiya took a stab at it — check it out below.

Main image: Jamie Hagiya/Instagram