well, 50k was for the Final. In the group phase I averaged 27k per matchday (and I won the group). In the play-offs, I did ~20k, ~30k (QFs) and ~40k, 35k (SF).
The whole idea is that you don't have to be a walking titan. The competition is played on selected Match Days and many players, myself included, simply aim at the important games (imagine that the day before my 49k, I did... 880 steps)