Many people, especially men, want to focus on their biceps when they start working out because they are highly noticed. Developing the arms is not that different than toning other muscles in the body. Building more size a combination of several factors. They include progressive overload to stimulate growth, working to the point of failure on your last one or two repetitions, working on the eccentric lengthening of the muscle, and periodically changing the movements to challenge you and provide variety, according to Deb Preachuk, Foundation Training Certified Instructor and Corrective Exercise & Posture Alignment Specialist. Focus on moves that require shortening and lengthening the distance of the elbow to the wrist, therefore recruiting the elbow flexors – biceps brachii, brachialis and brachioradialis.