With sizeable muscles, you're carrying more weight, which would be counterproductive to endurance performance, it would be like running a long distance while carrying a suitcase. Brad Schoenfeld More Quotes by Brad Schoenfeld More Quotes From Brad Schoenfeld The most important thing is to back off a little for the first week, choose a weight where you will be able to stop several reps short of failure on your sets. The following week you should be able to train at your previous level, assuming the reason for stopping wasn't an illness or injury. Brad Schoenfeld health-news