HOW: You can do this exercise both as a static or dynamic workout. Most effective is the dynamic motion which requires both strength and coordination; Lean forward on a chair with wheels and assume the plank position, lower arms resting firmly on the cushion and upper arms in vertical position. Let the chair roll forward away from you as far as you can manage and then pull it back towards you again. Repeat! It’s a very effective workout and you will instantly feel your abs getting a full rundown.
It’s easier as a static workout. Then you just lean forward in a plank position and hold for as long as you can. You can also do this on a chair without wheels.
Exercise: The Invisible chair
Situation: On the phone
The Invisible chair is a killer leg exercise for when you are on the phone. Find an open wall to sit against. Try to get as close to sitting in a 90° angle as possible and keep sitting for as long as you can. It might also be a good idea to split this workout into a couple of sets because otherwise the person you are on the phone with might start to wonder why you sound funny.