The installation of every previously mentioned plugins will be required once after the theme activation.
Install them and Active them
In case if automatic plugin installation fail (as a rule it is because of your server settings), you can install them manually via your Dashboard: Plugins > Add New > Upload Plugin > Browse plugins archives.
Or via FTP, by uploading and extracting the plugin zip files into wp-content/plugins folder. You can find the zip files for plugin installation in the theme folder athlete/admin/plugins.