People this weekend have witnessed two incredible feats of human endurance.
Runner Brigid Kosgei smashed the women's marathon world record at the Chicago Marathon on Sunday, completing the 26.2 mile race in 2-hours 14-minutes and 4-seconds.
That is 81-seconds faster than the previous record set by legendary runner Paula Radcliffe in 2003 at the London Marathon.
There are a few steps remaining for the new world record to be confirmed, but as the Chicago Marathon is an official open race marathon, there are unlikely to be any problems.
A day earlier on Saturday, the Olympic champion and world record holder marathon runner Eliud Kipchoge of Kenya sent shockwaves through the world of sport by doing something many once thought was impossible, becoming the first athlete to run a marathon in less than two hours.
The 34-year-old ran the course in 1-hour 59-minutes and 40-seconds at an event specifically set up for the attempt in the Austrian capital of Vienna.
But it won't count as an official world record, as it wasn't an open race.
It was his second attempt at breaking the two-hour barrier, after missing out by 26 seconds at a similar event on a Formula One track in Italy in 2017.
Won Jung-hwan, Arirang News.