If you really want to put your abdominal muscles to the test, give this leg-lowering test a go. Lying on your back, you should start with your legs pointing straight up in the air. Then, all you need to do is start gradually lowering them towards the ground (without arching your back). The lower you can get, the better your core strength.

“There should only be a small space between your back and the floor, and as soon as you feel this space expand or your back arch, rest and reset,” recommends Lucia. “Ideally you would work on this until you can lower your legs to at least a 45-degree angle without compromising your lower spine position and keeping your legs straight.”

If you want to make this test even harder, then you can try adding in some modifications. “Advance the exercise by lifting the arms straight up or behind you next to your ears,” McLachlan says. “You could also bring your head, neck and shoulders off the floor and increase the time you can maintain the position as your core strength improves.”

The key is making sure that your form never falters after these modifications are made. If raising your arms makes your back arch, for example, you’ll need to go back and work on nailing that position before you go any further.

Want to build better core strength? Try these 3 PT-approved tests first