At some point, I’m going to be asking people to sponsor me for something so I can raise money for a charity thats important to me. Recently, my friends have been asking for money for things they’re doing but they’re raising the money so they can do various things for free (skydiving/trekking etc…), not because they care about the charity. I don’t want to support the charities they’ve chosen but I want them to support me and mine…

Whats the polite thing to do here?

INSTRUCT ME, INTERNETS.