Los Angeles, California – After getting the warmed up with an epic arm-wrestiling contest, Kendall Jenner, Khloe, Kourtney, and Kim Kardashian squared off against the Jenner sisters in a homemade Spartan-style racecourse to prove who's strongest star of Keeping Up With the Kardashians.

The obstacle course was no joke, and might have even surprised all four of the sisters with its difficulty. Still, a winner had to be named.

Despite Kim discovering a cyst behind her knee after a preliminary volleyball, the Kardashians were ready to show the Jenners who the true athletes of the family were.

With an Olympic athlete as a dad, Kendall and Kylie were equally confident of their chances to take the prize.

On the day of the event, things started to shift gears on both sides of the family. First, the Kardashians got word from Kendall that Kylie wasn't going to make it due to a sinus infection.

After complaining to their trainers about the convenience of Kylie's illness, Kim and Kourtney started showing their own signs of weakness. When the gang was warming up poolside before the event, Kim's knee issue came back with a vengeance. When doing basic jumping jacks, Kim winced in pain, saying her knee was just not having it.

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Kourtney and Khloe made it clear that they weren't going to give up just because one of their clan was down, and opted to give the solo-performing Kendall for her money.

First on the track was Khloe, who set the time Kendall had to beat. Her strong but slender model frame made it a toss up whether she could perform in a fully physical competition, but she quickly proved the doubters wrong and crossed the finish line a full 20 seconds ahead of Khloe.

It was all on 41-year-old Kourtney to bring home gold for the Kardashian clan. Having nearly two decades of staying fit over Kendall meant her odds her good and she certainly started off at a swift pace.

It was a real nail-biter, but Kourtney ended up falling four seconds short, so the bragging right went to the Jenners.

Although their mom, Kris Jenner, insisted that everyone who finished the course was a winner, there's no doubt that second place is as good as last in this notoriously competitive family.