The eldest Kardashian sister has a social media feed full of swimsuit pics (yes, even in the snow), gorgeous magazine spreads, and sweaty post-workout selfies. She's always posting photos of her visible abs, toned thighs and shoulders, and of course, that famous Kardashian backside.

View this post on Instagram A post shared by Kourtney Kardashian (@kourtneykardash) on Apr 9, 2018 at 1:56pm PDT

But what exactly does the 39-year-old do to keep her fitness so on point-and her sculpted abs so defined? Read on to learn about Kourtney Kardashian's workout.

1. A trainer kicks her butt.

View this post on Instagram A post shared by Kourtney Kardashian (@kourtneykardash) on Mar 31, 2016 at 10:57am PDT

On her app , Kourtney used to share a lot of info on what she did during her workouts-many led by trainer, Don Brooks ( @donamatrixtraining ), using his method coined "The Don-A-Matrix Method." This workout technique is "set up to resemble a sports game format consisting of four quarters," Brooks told E! News . "Each quarter has three sets of two different exercises, combined with rest or relief periods after each quarter. We use the resist-a-bands a lot-the bands are very effective for toning without bulking or injury."

Brooks' workouts generally involve strength-training exercises mixed with some crazy intense cardio moves. Another YouTube video teaser shows Kourtney using battle ropes, BOSU balls, and a TRX suspension trainer.

E! Online also cites Amanda Lee as one of Kourtneys trainers. Lee reveals that she does a lot of HIIT workouts with the Kardashian sisters, as well as exercises like lunges and squats to fatigue (gotta work that booty!).

2. She counts on workout buddies.

View this post on Instagram A post shared by Khlo (@khloekardashian) on Mar 17, 2016 at 10:03am PDT

And usually, its sisters Khloe or Kim (more often the former). Youll often see one of the Kardashian sibs showing off their gym picks-including badass photos of their workouts, or what they look like after the sweat (which is always fabulous, of course).

Kourtney credits her sisters for motivating her to get to the gym and stick to a regular workout schedule. "I know for my body, I need four to five days a week of working out," she told E! News . "Khloe and I really push each other to do that."

Khloe has also shared how she cant get over her Kourtneys abs. "Can you believe my sisters abs?!?!??," she captioned one photo . "I see you boo!!!! I miss my workout buddy!!! You're my motivation!"

3. She moves it outside.

View this post on Instagram A post shared by Kourtney Kardashian (@kourtneykardash) on Jan 7, 2019 at 5:32pm PST

Just recently, Kourtney posted a photo of herself (along with Kylie and Kendall), geared up in their winter attire and ready to hit the slopes. According to another IG post , she was in Aspen, Colorado with the entire fam, kicking off her 2019 workout regime on skis.

When the weather is warm, Kourtney has also been known to hike around SoCal and play a little pool volleyball and tennis . Because fitness doesnt always need to be killer-it can be fun too!

4. She sneaks in cardio.

View this post on Instagram A post shared by Kourtney Kardashian Snapchat (@kourtneysnapchat) on Sep 1, 2017 at 9:40am PDT

According to a video she posted on her YouTube channel , Kourtney is all about burpees and mountain climbers (dang, kudos). And to warm up, she loves to jump rope .

5. She throws punches.

View this post on Instagram A post shared by Kourtney Kardashian (@kourtneykardash) on May 1, 2018 at 7:42am PDT

Another IG pic reveals that Kourt isnt afraid to fight. Like many celebs, Kourtney has embraced boxing as a badass total-body workout. She looks sweaty and super happy, sporting a pair of boxing gloves and standing near some bags.

6. She stays active on vacation.

View this post on Instagram A post shared by Kourtney Kardashian (@kourtneykardash) on Apr 9, 2018 at 1:46pm PDT

If you know the Kardashians, you know they like to travel-usually as a family, but also solo. Either way, Kourtney stay active. Just check out these bike riding and paddleboarding pics.