core workouts and their trouble in my challenge

i've added the t25 ab workout at the suggestion of my brother. this is replacing yoga on my workout week. i wasn't getting much from it as i am not flexible enough to do most of the moves. also i'd fall down a lot which lead me to believe my core isn't strong enough. anyhow, i started doing that workout. i've started to notice a fun side effect, strangely enough it clears out my system. like nothing sticks around very long. not sure if that is a direct result of the workout. though i do feel great this morning. a little tired, but pretty good otherwise. i'm not as sore as i expected even with my recovery speed in the garbage.