If you're trying to drive traffic to a certain site after an athlete registers, such as a Sponsor or Charity page, you can enable this with the following steps:
Go to Settings
Scroll towards the bottom of the page and set Enable Registration Redirect to Yes
Type in the destination web address you want to redirect the users to
Once the Athlete completes the registration process, they will be redirected to the web address you specify.
After the athlete completes payment, they'll be presented a confirmation page and then a redirect to the site you specify.