I have just read the article "The Truth About Bodybuilding Arm Measurements" http://www.testosterone.net/html/body_90truth.html I have just read the article "The Truth About Bodybuilding Arm Measurements" It says, to take accurate measurements, position your upper arm so that it's parallel to the floor, with the elbow pointing directly ahead of you. Measure the arm at its greatest girth, which should be at the peak of the biceps. Make sure that the "circle" formed by the tape is perpendicular to the ground. Are you supposed to tense the muscle or relax it, while taking the measurement?