Light Weight High Reps To Not Gain Size?

This has been one of the most misunderstood concepts in training. Many ( more gals than guys) think that lifting light weights for higher reps is the key to not gain size. This is completely opposite from what the science has found, if you open most strength and conditioning or exercise science text you will see that they touch on the subject of muscle growth also called hypertrophy. They all say that to add size, the muscle needed to be torn, those slight tears in the muscle will cause growth. The way that you get that growth is "time under tension" which means how long the muscle is being worked. There are 2 ways to get this tension:

1. Tempo- this has to do with the rhythm that you lift or lower a set weight. There are 3 muscle actions, concentric (shortening of muscle) , isometric (stabilization of muscle)  and eccentric (lengthening of muscle). Remember that grown comes from tearing the muscle, the eccentric or lengthening of the muscle is were the highest levels of muscle tearing happens. Which means if you extend the time that you lengthen a muscle the more growth you can see in time. For example, when performing a curl, try lifting the weight for a 2 count and than lowering it for a 8-10 count, for about 10 reps and you will see what I mean.

2. Volume- adding volume or changing the sets and reps in your workout is another way to get time under tension. This is were the statement that many believe about doing light weight for low reps gets debunked. The more volume your muscles are under the more tears will develop, which inherently will cause your body to adapt by adding muscle, which is size!!