Ages ago when I was trying different ab exercises, I was on my final set of incline reverse crunches, and I was using a bench that has the functionality of inclining. I inclined it to maximum setting, and began doing my incline reverse crunches. My abs were feeling the burn, and shaking like crazy. The vibrations of my core ended up jumping the supporting bar (of the incline bench) out, and the incline bench declined by itself forcefully and fast (it dropped) to becoming a normal bench whilst I was still on it. It made a loud bang sound, and I looked around to find about 5 people asking me if I was okay. Awkward.