If you want to know what riding 1,758 miles over 17 days in the Tour de France can do to a person's legs, Polish cyclist Pawel Poljanski has the answer in a single photo.
After riding in the 16th stage of cycling's most prestigious event on Tuesday, Poljanski, 27, posted a picture of his legs on Instagram, complete with bulging veins and some sunburn for good measure.
"After sixteen stages, I think my legs look little tired,'' he wrote in the understatement of the year.
Medical experts attribute the condition to a massive amount of blood moving through the veins, which causes them to bulge. "Normal blood flow in our legs is around 5 liters," Christopher Travers, an exercise physiologist at Cleveland Clinic Sports Health and Cleveland Clinic Executive Health, told TODAY via email. "In elite cyclists, during maximum effort, the amount of blood flow could be 8 times that (normal) amount." Travers noted that it's not a life-threatening condition and can be treated with rest and active recovery.
In 2014, British cyclist Chris Froome showed off some similarly veiny legs during a race. He is currently in first place in this year's Tour de France.
Froome and Poljanski both take a backseat to U.S. rider George Hincapie, who suffered from a stomach-churning case of unsightly varicose veins in the 2011 Tour de France.
Unfortunately for Poljanski, his wildly vascular legs still have plenty of work to do.
There are five more stages and 441 miles to go before the race ends in Paris on Sunday.
Follow TODAY.com writer Scott Stump on Twitter.