Ok, new thread. It has been a good idea to open a private forum where posting this things.
My lower back extension it's a mess, it's one on my biggest weak links by far and I know it very well.
The first day with F1 I tried mastery on this exercise and I just completed 1 round and 30s of next one, so, great thing.
Having said that, I have started again on week 5, 4x24, numbers that I can manage, but (and that is the question), with wich flexibility?
Of course my flexibility on extension it's not the same that the athlete in the video, except for torso that it's the same, but lower back and legs...
Do I have improve my flexibility on extension (lumbar spine) in order to get the same flexibility and, of course, start at week 1?
Thanks.