Ins & Outs Core Strength Challenge

This challenge is a measure of abdominal core muscle strength. The aim is to do as many 'ins and outs' as possible without pause. 

This is how the exercise is performed (description and video): 

For an in and out you start seated with hands raised at your sides, knees bent with feet on the floor. Raise your feet off the ground and bring the knees in towards your chest with arms doing the same. This is the test start position. Straighten your legs out in front of you and your arms out to the sides, then back in to the chest, without the feet touching the floor. This is one complete repetition. Repeat this movement as many times as possible.