This is a great warm up exercise combining mobility and strength. You will work through shoulder and hamstring mobility and shoulder and core strength.
To perform this exercise get into your press up position with your legs slightly wider apart than usual. In this position you should have your arms approximately shoulder width apart and you should be looking in front and in the centre of your two hands creating a triangle.
From here reach back with one arm touching the opposite toe, while doing this your bum will come up and into the air towards the ceiling. Come back into the press up position and repeat with the other arm reaching for the opposite toe.
You can increase the speed of this movement to make it more challenging. However it is important to ensure you remain in control throughout.