50 minute jog, lol.
But FRA is very very big. But we were still able to run the length of the entire airport in just over 10 minutes when connecting from CDG to VCE. We ran like hell, it's entirely possible that it was about 2 miles.
The 5 minutes is once you get outside, figure on a 10-30 minute walk from your gate just to get outside. My wife thought I was nuts, but later agreed it was totally worth it.
Also everyone in the airport will deny existence of the FCT to you and direct you to the regular FCL. We were told by a few agents it didn't exist and by one agent that it could not be reached by connecting passengers. Hogwash.
Yes, for some strange reason, no one knows of the fct. Or they are not supposed to talk about it?
Your wife thought you were nuts, and after running the marathon, she was too exhausted to think, so you just un-nutted.
My dear friend, not in FRA, or CDG or AMS will you run in 10 minutes from one side of the airport to another. Not even in BRU from B70 to A70 (some call the A terminal also M terminal, but by people using the A/M schengen terminal, its affectionately known as "the yimach shemoy terminal")