a plank that has to resist rotation as well as extension, because the surface
under your forearms will not stay still
drawing circles moves the point of support around you, so the direction the
trunk has to brace against changes continuously through the set
the hardest trunk hold here that needs no load at all
Execution
Set your forearms on a stability ball and extend your legs behind you, feet
apart for a stable base. Lift your hips so your body makes a straight line from
head to heels.
hold the plank position before the ball starts moving
draw slow circles with your forearms, keeping the circles small at first
keep your hips square and level as the ball travels
reverse direction halfway through the set
stop the set the moment your hips start dropping or twisting
Widen the circles to make it harder before you think about adding time.
Purpose
a plank that has to resist rotation as well as extension, because the surface
under your forearms will not stay still
drawing circles moves the point of support around you, so the direction the
trunk has to brace against changes continuously through the set
the hardest trunk hold here that needs no load at all
Execution
Set your forearms on a stability ball and extend your legs behind you, feet
apart for a stable base. Lift your hips so your body makes a straight line from
head to heels.
hold the plank position before the ball starts moving
draw slow circles with your forearms, keeping the circles small at first
keep your hips square and level as the ball travels
reverse direction halfway through the set
stop the set the moment your hips start dropping or twisting
Widen the circles to make it harder before you think about adding time.