Well, Sophie, there's no easy way to do it.
Unfortunately, we as a people tend to avoid contact with each other, allowing other things to become more important in our lives, lately, making face to face conversation difficult.
The best advice I can give you is to sit your parents down, seriously, but respectfully, and tell them with a straight face and an even tone, that this is very important to you. You want them to understand this about you, and you want them to be a little more involved in your life. So, you want them to at least try and read this stuff and understand why this means so much to you. Explain to them how Parkour makes you feel, why you want to do it so much. Explain to them that you want them to be supportive, because this is your passion.
You're their daughter, and they love you. Therefore, if you handle this carefully and sincerely, they'll give your situation some thought. Your bond as a family will win in the end, and if you're serious in your passion, they'll understand and support you. Trust me on this one. Did the same thing with my family a while back.
