Other than actually activating your core (and shooting for intensity over duration), the key to making planks not suck is to keep your mind busy, whether that's lifting limbs, walking around, or moving weights.
This exercise will hammer the trunk when you maintain a rigid plank. And once you've got that down, you can raise the difficulty by increasing the load or moving the weight in front of the hands.
Stimulants can really get you amped up for a tough workout, but do they have other effects as well? Dr. Lowery hooked himself up to fancy lab equipment to find out.