3x planks normal (player stands in pump position but not on his hands but on his elbows)
3x planks left (player lies down sideways and stretches his whole body on his elbows and ankles)
3x planks on the right (same as previous)
3x leg lifts (lie on back, lift legs stretched for a certain time, can be made easier by putting hands under the buttocks...legs as low as possible above the ground)
3x superman (on hands and knees, at the start of the time they simultaneously extend their left arm and right leg, then right arm left leg etc...)