(Please indulge a brief moment of brotherly bragging: My sister, Ali, is a phenomenal athlete ... the most common cause is drinking too much water, which dilutes the body’s sodium levels.

He recommends athletes drink water throughout the day -- rather than too much at once. "Not just scheduled water breaks," Anderson said. "Also, you want to have scheduled water breaks in time off.

It turns out the murky green water was just the start of athletes' woes at the Rio aquatics center. Now the water athletes' have to contend with eye-stinging amounts of chlorine saturating the ...