Add Yahoo as a preferred source to see more of our stories on Google. How to do the perfect side plank, and how to make it easier (and harder). Planks are hard. Even just 30 seconds in plank position ...
The key is knowing how to do a plank, however. As good as the exercise is, you have to do it exactly right to reap the benefits. As one of the best core exercises to do at home, the plank can also ...