No it can't actually, i made a entire post about this, mental energey physical energy thing already :|, what can be improved is your mental / spiritual energy aspect...
You chakra reserves like energy in a human , grows as you grow , through working out etc, you can utilize that energy more and more and more, if you could have run 10 meters then get tired, after training you could run 20 meters then feel tired ( mental energy ) But the 20meters was always what your body was potentially capable of doing
physical + mental energy = chakra