FL/PE2

For some reason, while doing FL/PE2 (bent hollow body rock), my body slowly shifting/ moving downward after every rep. I'm doing this on top of a yoga mat. I started in the middle of the mat and because I'm slowly moving downward, after 36 reps I end up outside of the mat. 

 

1. Anyone experience this too? What could possibly causing this? Is this need to be fixed for mastery?

2. Is it ok to do this PE on the mat or it has to be on the floor?

 

Thanks in advance!

I've experienced that just once. I noticed that I was moving my hips too much to create momentum in order to rock. I've fixed that and it has never happened again.

Ps: of course you can do that on a mat (the floor where the athletes in the course's videos perform the exercises is a soft floor). On the floor is just straight torture

Thanks EdStand. I'll try to see if I can fix this next time. I'll take a careful look on the hip issue.