5 Hardcore Celebrity Ab Routines to Motivate You In 2015—Watch Now!

You know what January means? Time to start on those New Year fitness resolutions. Like, immediately. Chop, chop!

If one of your goals happens to be tummy-focused then stick around because we've rounded up five hardcore ab workouts that are sure to whittle your middle in no time. Or, more accurately, in just a few weeks. 

That's right, we're borrowing a few workout tricks from Jessica Alba, Brooke Burke and more celebs with fab abs. So allow Instagram to become your personal trainer by watching these videos below. 

How does Kendall Jenner keep her stomach trim? The Keeping Up With The Kardashians star's trainer Gunnar Peterson puts her to work with some challenging exercises.

Peterson instructs the 19-year-old to keep her feet up and core engaged while throwing a ball overhead at the trampoline. If you don't have a trampoline, try substituting a friend. The model makes it look easy, but we're pretty sure it'll only take a few reps to feel the burn.