Leeds won 3-2 on Sunday thanks to goals from Joël Piroe, Willy Gnonto and Lukas Nmecha.
Farke said: “It is still pre-season and the end of the third week is normally the most difficult part of pre-season,.
“Normally the most exhausting period of training camp was for this game. You could feel that there is a difference.
“In the last 24 hours we had three training sessions so, yeah, you could see this also a bit mentally and then physically.
“For that I am quite pleased that we still found a way to win this game. It is a side that was nearly promoted to the Bundesliga last season so I am happy with the win.
“It was a pretty important test for us and also for the boys to show some resilience when they are not really fully recovered and not sharp and not really fresh and ready to go.
“I liked the resilience and still that we had the will to win this game. So overall, I think also an important test for us.”