Core strength is vital for almost every activity. This includes walking, running, and lifting things. Unfortunately there are a bunch of us who don't have good core strength. One of the common symptoms of having a weak core is bad posture and back pain.
A 21-day workout program was prepared by Albert Matheny of Soho Strength Lab and Promix Nutrition. It only requires 15 minutes per day! There are only 3 exercises involved but the reps increase day by day.
Side Plank with Knee to Elbow
Spiderman Plank Crunch
Learn how to do these exercises by clicking HERE.