Kris, Kourtney and Kylie know how to work it in workoutwear!

The Kardashian-Jenner girls all dressed down on Saturday -- Kris and Kourtney, to take Mason and Penelope to the farmers' market, along with Kris' man Corey Gamble; and Kylie, for a sushi lunch in Calabasas.

The first group made their way through the market and the mall with Kourt's young kids -- son Reign stayed home. Corey even pitched in to pick up little Penelope in his arms and carry her to the car as she started to get tired. Looks like he's really becoming part of the family!

Kris sported black Spandex topped off with a Yeezus cap and Yeezy Boosts to boot! While Kourt chose an unusual onesie over leggings. Gotta say, she looked kinda hot, but the risk of camel toe in this get-up is pretty high!

Meanwhile, Kylie sported her usual tight yoga pants with a sweatshirt and cap. The youngest Jenner showed off her pert (and injected) derriere as she got into her baby blue Mercedes G-Wagon after lunch at Sugarfish in Calabasas.

Kylie was the victim of a brutal hair extensions attack Friday night after the Chris Brown concert. Some b*tches in the parking lot grabbed Kylie's fake hair -- no doubt jealous of her expensive human hair weave. But the 18-year-old brushed it off and ran to her car and headed home with her manly man Tyga whose always there to save the day (because who wouldn't be terrified of a 5-foot dude with chicken legs and an overbite). Anyway, all is well in Kylie world now ... whew!