Along with exercising the smooth muscle to cause growth, you're also expanding the tunica albuginea.

The tunica is a strong layer of tissue that surrounds the penis chambers and smooth muscle. It serves to govern the size of the erect penis similar to how a bicycle tire limits the expansion of the inner tube inside. As you enlarge the tunica (bike tire), the smooth muscle (inner tube) expands beyond its original size.

Peyronie’s disease—a severe penis curve—is also caused by fibrosis in the tunica. By using the PenisMaster Extender and certain exercises found in the plan, the tunica can be straightened, reducing a curve by more than 50 percent.

In Exercising the Penis, you'll learn the details of how the tunica, the circular chambers in the penis, and their smooth muscle all play a role in improving and enlarging your penis. More importantly, when combined with the BetterMan Interactive Course, you’ll learn over 50 exercises that workout your penis in unique ways – causing it to grow bigger and harder.

"The BetterMan Plan combines the best exercises and tools needed to enlarge your penis and make it harder."