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 ...

The plank challenge is a 30-day program to strengthen the core and build up endurance. Each day of the challenge, you’ll gradually increase the amount of time that you hold a plank. By day 12 of the ...