4 KILLER BIG BACK Exercises for MASS [BIGGER Back Workout!!]. Looking to build a bigger and thicker back? Want some wider lats? Need a results-driven “big-back formula”. You’ve come to the right place! In today’s video I’ll be walking you through 2 vertical pulling (lat widening) and 2 horizontal pulling (back thickening) exercises designed to build a bigger and thicker back! Let’s get into it!