Cycling is a great sport—unless you are participating in the Tour de France, in which case, it'll make your legs look like 'roided up deer legs on a bad day. On Tuesday, cyclist Pawel Poljanski posted an Instagram of his (ravaged) legs after 16 stages of the classic race. In the caption he wrote, "After sixteen stages I think my legs look little tired." OH, YOU THINK?

After sixteen stages I think my legs look little tired 😬 #tourdefrance

A post shared by Paweł Poljański (@p.poljanski) on Jul 18, 2017 at 10:04am PDT

This unsettling but still really interesting and cool picture has now been picked up by several sports outlets, and some have explained the reason his legs look like veiny beef jerky.

Almost three-weeks training camp on Sierra is done. Now it's time for Polish Championships and @letourdefrance! #borahansgrohe #cycling #cyclinglife #specialized #sierrnevada

A post shared by Paweł Poljański (@p.poljanski) on Jun 13, 2017 at 6:24am PDT

It's a condition called enhanced vascularity. Dr. Bradley Launikonis from the University of Queensland's School of Biomedical Science told ABC News that elite cyclists have twice as much blood flow to their legs than do recreational bicyclists. He explaind that arteries carry blood quickly to the leg muscles that need oxygen, but due to the athlete pushing himself to his limits, the blood pools in the veins after being in the legs for a long time, making the veins overly visible. Cool! And also, gross!

enhanced vascularity
— nostromo (@StokedToLive) July 19, 2017

This isn't particularly unusual for a cyclist after such an intense workout. In 2014, professional cyclist Chris Froome posted a picture of his legs. They look pretty similar, if slightly less sunburned.

Our man @chrisfroome is looking absolutely ripped ahead of #LBL on Sunday! (Photo: @michellecound) #VaVaFroome pic.twitter.com/UGePCkvwKU
— Team Sky 🚲 (@TeamSky) April 23, 2014

And just about every year, a cyclist has to put up with accusations from the public about using steroids.

You sure it's not a result of all the performance enhancement drugs that are very prominent amongst cyclists?
— Thabani (@tkmash) July 19, 2017

https://twitter.com/blockbuilder31/status/887580912401174530

just to be thorough, please give list of controlled substances that were used
— Arne Petimezas (@APetimezas) July 19, 2017

But performance enhancing drugs are not to blame.

This is what it looks like when you don't cheat.
— Mel (@notsomefaker) July 19, 2017

Twitter basically could not handle seeing these pieces of human leather. Can you blame them?

This looks like something created by a horror film makeup team. Wow
— Tony Holt (@TonyCrimeWriter) July 18, 2017

And I'm like... pic.twitter.com/AlsPMiHMHj
— Usama Aftab (@robingosh) July 19, 2017

Looks like Melisandre's legs after she took the necklace off....😖#GameOfThrones
— LSUguru (@LSU_fan77) July 18, 2017

I though another well preserved mummy had been discovered.
— Kevin Litke (@klitke605) July 19, 2017

Couldn't even begin to fathom 😳 Amazing how far the mind can push the body
— Kevin (@i_am_the_kdubb) July 19, 2017

Looks like a bodybuilder legs when they are shredded for a contest
— Derek Zane Learmonth (@ddritzenhein) July 19, 2017

Many GIFs were used to express various emotions, mainly being weirded out (but, like, in a good way).

pic.twitter.com/8LkXnMZUBL
— Ryan Borowiak (@RynoCub2344) July 18, 2017

pic.twitter.com/uVtT0iwxg9
— Tenisa Pritchett (@Bama_T) July 18, 2017

pic.twitter.com/n4dJej7vSM
— @'n Aint Eazy® (@Three1VII) July 18, 2017

It just goes to show how far the human body can be pushed, and all the amazing feats it can accomplish with serious training. The human body is a marvel of natural engineering—and also sometimes slightly disgusting.

Cyclist posts pictures of his legs after the Tour de France. Twitter is freaked out.