If You Can Hold This Plank for 60 Seconds, You're Stronger Than Most
You’ve probably done a plank or two in your time. Maybe even groaned through a shaky 30 seconds or challenged yourself to a two-minute burn. But a clear difference exists between a basic plank and a genuinely advanced one. Shutterstock The extended arm plank separates the casual core trainer from the serious core crusher. Hold it long enough and you are not just fit you are unshakable. The extended arm plank might look simple, but it is anything but easy....