Recently went to buy some shirts to wear at work, I exercise a lot (cardio, weight-training and calisthenics) so I have pretty large shoulders and a (smaller? regular?) waist.
I tried explaining that I'm an "inverted triangle" body type and was told something called "Y体", at first I thought it made sense but when I tried them on, the ones that fit my waist I couldn't even get my forearms into, and the ones that fit my shoulders and arms were like 1.5 times the size of my waist, came to the conclusion that this "Y体" is just a "rectangle" body type (why it's called "Y" beats me...).
How would I explain an "inverted triangle" body type in Japanese?