The two reality TV star looked to be working hard with three other ladies.Kendall had a white tank top over a black bra with black leggings and sneakers and her hair tied back. The Fendi spokesperson had on no makeup.
Kourtney opted for a black sports bra, leggings and sneakers with her hair in a messy knot.
It appeared as if they were working out in a very upscale garage. The eldest Kardashian noted they were with pal Amanda Elise Lee, who is a model and trainer.
There was a crying emoji added to the clip.
The two are a visually interesting pairing as Kourtney is the shortest in the family at 5ft1in and Kendall is the tallest at 5ft10in.
The two used to be at odds but have become closer in recent years as detailed on a recent episode of Keeping Up With The Kardashians.
After bonding during a mud path at a spa, they started spending more time together.
While the ladies are working out together, across the globe their relative Brody Jenner was celebrating his marriage to fiance Kaitlynn.
They were surrounded by family and friends this holiday weekend.