Drinking too much water is dangerous

During intensive exercise keeping fluids level up is helpfull,
but in case of over dose its dangerous . Psycologist and
doctors tested blood samples from 400 runners completing
the marathon and found that 2.5 % of runners , which means
10 persons had sipped so much that they had diluted the
sodium levels in their blood to dangerous levels- condition
in medical term called HYPONATREMIA-risking collaspe
or death .It should be considered that weight gain after
exercise is good ,which indicates that u consumed
more liquid than u lost ,while loss of weight indicates
that u consumed less liquid as compare to u lost.