The key to rapid muscle growth, is to perform all your exercises well outside your comfort zone. If you had performed the barbell curl to the point of complete and momentary exhaustion, instead of "copping out" at the tenth. Then your bicep muscles would be forced to work harder than normal. Much harder. As a result, they would grow and build size rapidly.
What matters here is not the number of repetitions performed beyond the initial ten. What's most important is that you understand the reason behind the need to force yourself to work at higher levels of intensity. To produce the greatest possible muscle gains in the shortest possible time frame, you must continually strive to perform at a level well beyond your comfort zone.
If you perform a set of barbell curls until you can no longer lift the bar, no matter how hard you try, or how many pair of strides you split, then you will be involving the highest possible number of muscle fibers. It may not be the total number available, but it will be enough to produce massive increases in muscle size.
Muscle gains produced by a very small amount of intense exercise, will always be much, much more, than that produced by a large amount of low intensity exercise. It is never the quantity of exercise that produces muscle gains, it is always the quality.
Most guys who exercise today are completely ignorant of the need for maximum intensity in their workouts. And as a result, most are blind to their true potential. Even when they are training six days a week, most guys make have no muscle gains to show for it. They just don't know that they need to workout at a much higher level of intensity. But, in many cases they're just too damn lazy to do so.
If they don't exert the level of intensity needed, they will never achieve astounding muscle gains. So, unless you are content to train for years and have nothing to show for it like Frankie No-Gains and Jermima Got-No-Brains, you must accept and respect what is required of you. Your exercise must be brief, but it must be intense.
Trent Brook is the Author of "Huge Gains Fast - How to Get More Rock-Hard Muscle Mass In A Month Than You Now Get All Year. His "Huge Gains Fast" muscle building program is an easy-to-follow system so simple and understandable it's fully explained to you in just 4 easy steps! The Revised Edition is now available online at his website, http://www.hugegainsfast.com