phoenix_9286 - It's all about NOT faceplanting. Be careful, progress slowly, know your limits and respect them, and you're less likely to get hurt than you would be playing soccer or football.
Phantom-Seraph - The first part of the video is primarily strength/conditioning exercises that we do (that are heavily parkour influenced), and the second half is more straight-parkour. I really love doing the QM (quadrupedal motion (the thing going DOWN the stairs)), and it's a really fantastic full-body workout, but going up stairs like that is too easy, so the crab-walks up the stairs maintain the intensity of the workout.
Maeve - Then do so! There's a HUGE community in London, some of the best traceurs in the WORLD.
http://www.parkourgenerations.com/classes.php?p=women <-- here's an all-female class that meets in London. They also have a bunch of other classes. Barring that, I think a lot of the london crowd talks on [url]www.parkour.net[/url], so you can probably go to a bunch of real jams there (real jam versus gym/instructional session (you can learn just as well at a "real" jam)).