... the top (difficulty) is often a real test, even if like me, you spent your last year at university playing Mario Kart Double Dash and eating
Swiss roll until you passed in someone else's garden.
Comparing
Swiss ball exercises, Marshall et al. (2010) assessed rectus abdominis muscle activity during the plank with arms on the
Swiss ball, single - leg hip hyperextension from the push up position with legs on the
Swiss ball, single - leg squat against a wall on a
Swiss ball,
Swiss ball
roll outs, and
Swiss ball full body
rolls from a supine bent leg start position with the upper back on the ball, and rotating 90 degrees
until the shoulder and upper arm rests on the ball.