The plank is the perfect exercise to train your muscles. Not only do you have to tighten your abs, the plank trains different muscle groups.
In the past, sit-ups were always recommended to train the abs. Not necessarily anymore these days. For some people, sit-ups are too taxing on the back and neck.
The shelf boring? Nope, just look at these 7 variants>>
Which exercises do you do for your abs?
