Seems to me that having large breasts (as I do) will change your balance, and not for the better. This would be a drawback in athletic competition. And certainly large breasts can physically get in the way.
Playing 14-1 continuous rotation pool isn’t an athletic event in the general sense of the word, but I found that large breasts got in the way of my stroke. When I was playing daily, I had to wear a specific bra to get them out of the way; and I missed a shot more than once in neighborhood competition because my arm was slightly deflected by my right breast.
Still have no idea why they shrink when you exercise hard, except that if you are already a bit overweight, you may put some of the excess poundage on in the breast, which then shrinks a bit as you lose those pounds. It certainly doesn’t take a large loss to be apparent in something as small (relative to body size) as a breast.
magpye100, when you start a thread in response to one of Cecil’s columns, it’s helpful to other readers if you provide a link to that column. Saves search time, and keeps us on the same page, so we don’t get people re-stating what Cecil already said. No biggie, you’ll remember for next time.
I’m not exactly sure which column you meant, I’ve taken the liberty of making a guess and adding a link to the bottom of your post. If you meant a different column, please let me know by email (or REPORT the post, little ! in red triangle in upper right) and tell me which one you did mean, and I’ll fix.