Pedundum, I understand the anatomy and physiology, and I understand the penis holds a fairly small amount of blood (depending on size), which is why I qualified my question for “intense and long-term routines”. The penis may hold only 50mL (random estimate) of blood at a time, but say you are jelqing 3 times a day vigorously and you jelq out blood and bring in new blood a few times during each routine and you do this 6 days a week (100mLx3x6=1.8L/week) which is a pretty high percent of your blood volume. I’m not suggesting that all blood in your penis is destroyed, but what percent if any? If any damage did occur, it would certainly depend on many factors that may not apply to you, such as: RBC status in your body, RBC suceptibility to lysis (some people have weaker RBC’s due to specific enzyme deficiencies that I won’t do into), time PE’ing, type of exercies done, number of days a week, intensity of exercises, nutritional status, age, I could go on and on.
I must add that I am an avid PE’er and I do not have anemia or symptoms of anemia, nor am I claiming PE causes anemia. I do stand by the idea that it COULD damage red blood cells to some degree and the only way to know this for sure is by scientific experiment and not assumed understanding of physiology or lack of PE’ers displaying anemia or symptoms.