As the title suggests I need a bit of an explanation for this ‘core phenomenon’. I’m doing FB Strong (second time around) at the moment and this particular routine was scheduled on Day 13 and I thought fair enough, a bit of stretching and flexing, no problem. https://www.fitnessblender.com/videos/stretch-and-tone-for-core-stability-and-back-health

There wasn’t any, however, the following day, as I was getting out of bed as gracefully as one can possibly be at 5:30 in the morning on a cold November day, I noticed that my core is slightly sore, which took me by surprise because I’ve done this one,

https://www.fitnessblender.com/videos/30-minute-core-strength-fitness-blender-advanced-core-workout

and this one,

https://www.fitnessblender.com/videos/six-pack-burn-out-intense-abs-workout

and this one,

https://www.fitnessblender.com/videos/advanced-core-burning-workout-challenging-20-minute-abs-and-obliques-workout

and this one,

https://www.fitnessblender.com/videos/6-pack-abs-workout-six-pack-abs-or-bust

and this one

https://www.fitnessblender.com/videos/cardio-kickboxing-and-abs-workout-kickboxing-for-stress-and-cardio-benefits

and some others with ‘brutal’ or ‘advanced’ or ‘intense’ in their title so I'm familiar with the BURN and all that, but my core is rarely sore the following day.

So how? How? I keep asking the question in a Northern Irish accent. I might have some ideas, I just wanted to talk to you, really. :)