Agree with the others saying that you can't force them to do something they don't want to do.
I've always loved ballroom dancing. We started ballroom classes when DD was 3.When she was 4 I was stressing over finding a good partner. When she was 5, Isigned her up for private lessons, and entered her into a competition. She did great, by the way, got 3 first places out of 8 dances. But when she was 6 she said, I don't want to do this anymore, I want to do gymnastics instead. What can you do? We tried to convince her, bribe her, force her, nothing worked! She would go to class, but fool around for 45 minutes instead of dancing. So, we quit, and switched to gymnastics, and I never hear her complain. If she could spend 24 hours a day in gym, she would. LOL Haven't seen any first places yet,but it's only her first year competing.
You need to introduce a child to a variety of activities\sports, and let them choose for themselves what they want to do.