Kendall Jenner may have been dressed nearly from head to toe for her red carpet-ready Christmas update on Instagram, but we all know the Victoria's Secret model rocked insane abs underneath that black ballroom gown. The 26-year-old has snagged countless headlines with her fitness secrets and exercise routine over the years, proving that everyone wants to know how to get that perfect Kendall bod.As far as her rock-hard tummy is concerned, her ab workout is surprisingly easy and completely within reach to anyone who has just over 10 minutes to spare. Bonus: you can do it at home, so no need to for a trip to the gym. Details below.11-Minute Ab WorkoutThe secret to Kendall's chiseled abs is a short but comprehensive core workout you can do literally anytime and anywhere so long as you have some floor space and an exercise mat. Instead of hour-long routines that you need to fit into your schedule, the Calvin Klein face (and body) relies on an 11-minute circuit that has everything she needs to keep her stomach toned and provide that spot-on muscle definition.Starting off with a series of planks -- including a 30-second forearm plank, high and side planks, as well as a side plank with a crunch -- Kendall continues with a set of various crunches, after fitting in a few single arm and leg planks, a 15-second rocking plank, and a knee-to-elbow plank with five reps on each side.Scroll for the rest of her exercises!Crunch TimeKendall's 11-minute circuit includes all types of ab crunches that are just as varied as her planks. According to Cathy Spencer-Browning, VP of programming and training at MOSSA, "crunches develop the muscles on the front of the core" and are the surest way of getting that sculpted six-pack you've been dreaming about.The supermodel and entrepreneur performs 20 regular crunches as part of her routine, moving on to a 30-second bicycle crunch and a 20-second vertical crunch. Her ab workout also includes 15 frog crunches, finishing off 30 leg lifts (15 per leg).Hitting The Gym HardAccording to Byrdie, Kendall typically relies on her 11-minute ab workout when she's too busy working to hit the gym. The reality star has been working with the same personal trainer for years, consistently training for five days a week to maintain her jaw-dropping figure."To stay toned, I do a lot of ab work with my trainer, Gunnar Peterson, and occasionally I'll take a kickboxing class," Kendall told Harper's Bazaar back in 2016, giving readers some insight into what a typical day looks like for her. As expected, fitness is the first thing on her mind as soon as she wakes up. Read more below.Early BirdIt's no surprise to anyone that Kendall is an early bird. After all, you need to be up at sunrise if you're going to get through everything the 818 Tequila owner has on her plate on a daily basis.Dishing to Harper's Bazaar about her habits, Kendall revealed she's up at 6:30 a.m. and already in the gym by 7 a.m."I prefer to work out in the morning," she said, with fitness expert Rachel Attard detailing that Kendall does "a combination of strength, movement, and high-intensity workouts.""Most of her ab workouts are bodyweight only, which helps her achieve looking lean and toned," Attard wrote in an article dedicated to the model's fitness routine.Based on Kendall's bikini photos on Instagram, her workouts are definitely hitting the sweet spot.