What it tests
This is a great core strength test, but it also relies upon the upper body to stabilise the movement. The rotation tests a movement that we don't make often because you have to keep the upper body static and rotate the lower body.

How to do it
Start in a press-up position with feet up on a chair or gym ball. Bring your left knee in to your chest above the floor. Slowly rotate it around to the right, under your body and as high up as comfortably possible. Pause, then slowly return and rotate past the start so your leg and hips are fully rotated to the left. Repeat with your other leg.

Can't do it?
Build up to the Scorpion by holding the "up" position of a press-up to improve your static core strength,' suggests Coulthard. 'You can also hang from a pull-up bar, bring your knees up and then rotate them from side to side.

How you rate

Good: 10-15 reps

Average: 6-9 reps

Poor: 0-5 reps

Now try dragon flags. We dare you.