Pro Test 180

Here is your eight point guide to build a massive back. How to Build a Massive Back and Lats #1 - Your Back Is Larger You should realize that your back makes up about one third of your body's muscle mass. This means you need to do twice, maybe even three times as many sets of pulling than pressing. There are also way more muscles in the back (56) than in the chest (2).

http://www.getforeverhealthy.com/pro-test-180/