Lie on your back with your knees bent and feet flat on the mat, both arms straight by your sides.
Lift up your hips by squeezing your gluts, let your shoulders and feet take the weight.
Aim to have your feet directly below your knees, and a diagonal line from your shoulders to your knees.
Hold for 10 seconds and relax.
Repeat 5 times.
Progress by holding it for longer each time, aim for 1 minute or even longer.
Tips: You'll feel your lower back and bottom doing most the work. But focus on working your whole core (including abs) to keep your hips up. Be sure not to take any weight on your neck. Keep breathing throughout. Take steady breaths, never hold your breath.
To Make It Harder
This variation will work each side of your gluts that little bit harder.
It's the same as above, apart from your starting position.
This time, keep 1 foot flat on the floor and rest the other up across your knee.
Then continue the exercise as described above.
Tips: Keep your core balanced by doing equal amounts on each side.