Is it recently like this?
Perhaps a week off is what you need.

Sounds like your muscles stopped firing to me.
Probably excessive sets of going to failure for too many months? <--- I'm only hypothesizing, since you said sweat less.

BTW, you sure you got minum cukup air or not? And got sleep enough of not?

Ahahahah! Shane. X^D LOL

No lah, what I mean stop firing means that the muscles is like the muscles doesn't respond well to the signals from the brain.

I don't know lah, I just bantai and see if the hypothesis is correct. =P