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 PostsProud of me after 40 by RoxanneJune 19, 2011Limited Edition DVD CaseAugust 24, 2011The Eye Diet: What to Eat to Protect Your VisionJuly 4, 2016