November - "No Surrender November" by FIT KIT ATHLETICSISOMETRICS. That's a term that describes a type of muscle contraction where the length of that muscle doesn't change in length once it's engaged. For example a plank. The core complex, with all it's complexities, engaging at the same time contracting in harmony burning terribly just to keep the body from flopping to the floor! Take that vs. a traditional crunch. Same muscle group (for all intents and purposes) but now the "6 pack part) or Rectus