Rss Feed from PhP Code

I am currently building a new site with WordPress, and one of the main features we would like is the ability to have our Workout of the Day show up in the main blog feed. Right now, we do a post in our PhpBB forums for each WoD where members can comment and ask questions. The old site admin made a nice page that pulls the recent WoDs and displays them (https://gymnasticbodies.com/wod/index.php), but I’m not sure how to convert this into an RSS feed to integrate to our new site’s blog.

I know the code pulls directly from the MYSQL database to generate the entries, but beyond that I’m lost as to how to do this.