Actually how buff should any superheroine be. I think it’s really more up to the individual than as a whole to be really specific. You could exercise fairly often (especially with chores and playing folk games) and still eat junk food. In the case of hunter-gatherers, they certainly are fit but not so overly muscular given how hard it is to find food the next day.
(Bodybuilders, sumo wrestlers and sometimes weightlifters do the opposite by eating a lot.)
Though it’s also got to do with how fat they are. Hunter-gatherers are undoubtedly fit but also need some fat to survive as they have to endure from trying to find the right food. Given Tigra and Caitlin’s predatory inclinations (tiger-woman and wolf woman respectively), they’d lean closer towards hunter-gatherers given their diets.
Cats are obligate carnivores and dingo–type dogs can’t process starch any further. Tigra and Caitlin are doomed in a sense. Actually in the recent Wonder Woman comics, Cheetah’s doomed to consume human flesh. Though part of a supernatural curse, it makes sense that a half-carnivore would’ve this dilemma.
To be fair, growing numbers of cartoonists are adding muscle tone to superheroines (and any athletic female character in general). Makes sense that the newer generation’s more desensitised to muscular women (for whatever reason) and/or strive for more reality. In the sense of making them as fit as they should be since they barely so sedentary.
Then again there are fit fat people (weightlifters, sumo wrestlers) where whatever far they have’s stored right under the skin to any degree. I’m not saying that Caitlin and Tigra should be fat but given their diets and lifestyles, they’d be closer to hunter-gatherers (fit but generally not that ripped).
Wonder Woman, Supergirl and their ilk by contrast don’t have those dietary restrictions (though it could be up to personal preferences) and can afford to have a more developed physique. Again it’s like differences between bodybuilders and hunter-gatherers.
Both of them are fit yet the latter can’t afford to find more quality food and have to endure in order to wait for something. (Actually the same can be said of any fairly fit person who can’t always afford certain foods.) The former has access to it even if it’s not always in top shape.
(Though I get the impression that most bodybuilders, even when off-season, seem bigger than most hunter-gatherers but because the latter’s muscular only when necessary and the same can be said of people who do chores and folk games. Or rather any other sport.)