Unfortunately, once you complete registration it is not possible to update or edit the amount of money someone has contributed.
If you would like to contribute more money we encourage participants to invite a friend or family member to sign up and add your additional contribution on to them. Coordinate with them on how much you would like to contribute. This will make things more fun if you have someone to complete the workouts with!
The other option is to cancel your current registration, get a refund for your initial contribution, and re-register with the new amount you would like to contribute. Contact Games Support at email@example.com for more information regarding this.
Good luck and have fun!