For research into this subject, Anime Herald was fortunate enough to interview...prolific anime writer and critic Borealis Capps
Haha, I feel like you posting this article is a bit of a humblebrag.
Thanks for sharing though. I think that Dumbbells was a really fun show and I would love to see newer, better takes on a series like it, since I feel some of the things discussed in this article are totally fair. The one in particular that you brought up is how much the girls don't want to be too muscular, but rather just slim. This is something that is a recurring joke with Darkness in Konosuba as well. I mean, her role is to absorb damage for the party, muscles are kind of a prerequisite. That hangup of Darkness's never really made much sense to me.
I think it is interesting to compare Dumbbells to a series like Plus-Sized Elf. They both are ecchi as well as try to be educational, but they take things in very different directions (and not just the body-types). I eventually dropped the manga, but as it went, Plus-Sized Elf seemed to lean more into ecchi and less into education, probably because none of the characters hardly even tried to put those lessons into practice. Also, when the anime adaptation released, it was even more ecchi than the manga was.