halben on "Member profile update WPDB and trigger 3rd party DB update question"

I have a quick question/scenerio and if anyone can please point me in the right direction.

When a member update their profile, the WPDB is updated as well. How can I make/trigger an update to a 3rd party database? (WP already inserts post data to 3rd party DB already)

Should I use the action hook personal_options_update or edit_user_profile_update (I have custom meta fields)?

or something like this:

function my_profile_update( $user_id ) {
    if ( ! isset( $_POST[''] ) || '' == $_POST[''] ) {
        return;
    }
}
add_action( 'profile_update', 'db_profile_update' );

Thanks,
Halben