Hi Matthew,
you can use a standard page with a regular dataset.
you then set a filter to the dataset to only retrieve data that is owned by the current logged in user.
to retrieve the current user’s ID, use the wix-users module.
to set the filter to the dataset, use the wix-dataset module.
the filter should match the logged in user’s ID with the “_owner” field value in your workout collection.
that field always has the ID of the user that created the record.
hope this places you on the right path!