#1227 - Access denied; you need (at least one of) the SUPER privilege(s) for this operation

It means you don't have privileges to create the trigger with root@localhost user..

try removing definer from the trigger command:

CREATE DEFINER = root@localhost FUNCTION fnc_calcWalkedDistance

Simply remove "DEFINER=your user name@localhost" and run the SQL from phpmyadminwill works fine.

In case you are uploading an sql file on cpanel, then try and replace root with your cpanel username in your sql file.

in the case above you could write

CREATE DEFINER = control_panel_username@localhost FUNCTION fnc_calcWalkedDistance

then upload the file. Hope it helps