I'm using youtube api to get to know when a video is fully buffered

when the fraction is 1, the video is fully buffered
but I have to poll this function to check whether it is 1 and then get the time
like setInterval(display_fraction,1);
since a video could be tens of minutes
will this polling creates a heavy load on the browser/client and thus affect the video streaming? are there any other better polling methods or ways to detect when youtube finishes buffering?

BTW, the link for youtube api is: