mount kinabalu eh?
u climb via timpohon or mersilau?
if timpohon no need to train hard la. got stair everywhere. enough with jogging every evening.
if mersilau u need to train more because mersilau quite far than timpohon route. example bt caves stairs, bukit tabur, melawati. kem lolo, gunung nuang, bukit broga etc etc.

basically timpohon to laban rata - 3 hrs. mersilau to laban rata - 5-6 hrs.

been there via 2 routes already.

good luck and have fun.

ps : got heavy rain at the peak of kinabalu when im there. no scenery at all! thats why i climbed twice lol.