This issue came up in another thread today: The Back & Core program is designated a Difficulty Level II program. But it includes planks. A LOT of planks. (Two days out of every five is pretty much all plank work!) The Difficulty Level information in the Workout Manual states Level II programs include: "Standing and floor exercises - but no planks." (emphasis mine). Should Back & Core perhaps be reclassified on account of the new Difficulty Level rubric?