I am a parent myself so can understand some of the issues
best thing is to talk to your olds and find out what the reasons are for thier negativity. It could be
Frightened you will hurt yourself
Another costly fad
If you are serious probably the best thing to do is get to a meet with your parents and show them its fun and reasonably safe.
Talk to them and agree a course of action, most parents are not negative for the fun of it just concerened and /or uninformed