5 ab-sculpting workouts that can build core strength in the gym, according to personal trainers - Yahoo Sports

Gym machines can help you build strong ab muscles with weights and resistance more efficiently than bodyweight crunches, according to trainers.

The 12 Best Ab Exercises to Build Core Strength

The Awesome Abs Workout

Fact or fiction? Ab definition workouts exist

Forget sit-ups — this 10-minute standing ab workout builds real strength

You don't need crunches to build a stronger core — just 10 minutes and 5 exercises

Take 5 Minutes to Work your Way to Major Abs - Yahoo Sports

Watch Mark Wahlberg Hit an Upper Body Workout Hard

The Awesome Abs Workout

The Best 10-Minute Abdominal Workout for All Core Muscles

I tried this four-move bodyweight core workout, and it proved you don't need weights to build practical muscle

7 Core Exercises To Building Strength And Sculpting Abs