Yep, all those bad circulation problems. I use to feel all my heart beats,seemed liked at times that surely everyone else could see my body pulsing it was so bad, but I started taking magnesium and it not only took care of the hard beating but also the flip-flopping and the flutter cough thing. Now if my magnesium levels get low enough (I've been exposed to a lot of toxins and stress) I sometimes can feel my heart beat again and I know it's time to take a little extra!