kanasai.....like the sperms are adventurers can do all this sort
of thing...should make a movie on this...change Terminator 3 to
Sperm 3.haha...joking
but frankly spking...i read some books abt health, oso on men's
health. jus to share. SilverGal say correctly....men infertile is
sometime due to many reason.
smoking, drinking all these contribute to this too. N most
important, dun chong so much esp after marriage.
according to chinese medicine, at 11pm -1 am, blood circulate at
Liver n 1-3am at kidney. when this time u din sleep...they gonna do
OT.
so in long run it cause your infertility + no energy n stamina in
sex life.
or so call sperm got no nutrient.....sick man. no energy to break
egg oso...keke.. 
for those who want strong energy, take care of liver n
kidney..impt.
abit long story..pai seh.. 