I have talk to GM long time ago about this feature but they cant do it because everything done by developer in US. However in software engineer point of view this can be done easily.
See below algorithm.
If you press start marathorn check the item in inventory first, if already have fitness book then pop up the warning message "You Already have fitness book can not get it again" somrthing like this.
This is quite simple but it depend on developer whether they want to add it in or not.
GM in Thailand just forward our recommendation to them.
Again if this can be done it will be usefull for every server/player around the world.
