5:00 for Max Reps:
20 (Total) Plank Knee to Elbow
40 Arch Pulses
With the plank knee to elbows, you want to engage the shoulders by pressing firmly through the hands and rounding the upper back, then controlling your leg and holding your knee to your elbow for 1 second with each rep.
On the arch pulses, pull your shoulders blades together and elbows back with each lift, and you're going to feel a much more intense burn.