No more crunches! This trainer’s dumbbell workout takes under 20 minutes and builds stronger arms and abs at the same time

Kill two birds with one stone (dumbbell) in as little as 15 minutes using this trainer's abs and arms strength building workout.

A top strength coach says you only need these two exercises to build your abs

“The role of the abdominal muscles in spinal flexion is to create top-down flexion, moving the ribcage towards the pelvis and bottom-up flexion, moving the pelvis towards the ribcage.” To develop your ...