This was Michael Phelps toward the end of the 200 m butterfly final. (You can see exactly how close to the finish he was by contextualizing those staccato red marks* with an overhead photo of the pool.) He wound up finishing second to South Africa's Chad le Clos. Once upon a time, Phelps passed others like that.
But Phelps's silver medal did tie him for the all-time Olympic medal lead. So things could be worse.
*I'm told those are 15-meter marks.
For a handy master schedule of every Olympic event, click here.