Greg performs a Concentration Curl during STS March 19, 2008 by Cathe Friedrich Greg performs a Concentration Curl during STS Meso #2 – Back & Biceps. Categories: Behind The Scenes, Blog, STS, STS Mesocycle #2Tags: cathe, concentration curl, exercise dvd, exercise dvds, fitness dvd, fitness dvds, hypertrophy, mesocycle 2, STS, workout dvd, workout dvds Leave a Comment Related PostsHow to Boost Muscle Hypertrophy By Working Your Muscles from a Stretched PositionJanuary 17, 2021Health & Nutrition Trends for 2017: What’s Hot & What’s NotDecember 11, 20165 Ways to Stay on Track with Your Exercise Plan During the HolidaysDecember 7, 2014