For planks, I do 3x3x1minute with feet on a swiss ball. So front for 1 minute, rotate to one side for 1 mintue, then rotate to other side for 1 minute, for 3 rounds. Works a treat.
tried the elevated frontside plank (from the sofa) - excellent, 2 mins of this is equal to 1 min of the normal oblique plank, thank you for this - the routine is now balanced
tried the elevated frontside plank (from the sofa) - excellent, 2 mins of this is equal to 1 min of the normal oblique plank, thank you for this - the routine is now balanced