eli5: Why do women have lower peak strength compared men?


I’ve always been curious about how some (most in my experience) women who are considered at peak fitness levels are still weaker than men who are in average shape. It’s been described as “body chemistry” but I’ve never truly understood why. There are absolutely some exceptions, but even when looking at fitness charts, men are expected to be stronger than women in every category. Why?

In: Biology

It’s the hormones responsible for muscle growth. Men have more than women naturally and thus should be stronger if they had similar training and all other factors equal.

There are certainly plenty of women much stronger than an average man. Both men and women can be assisted by performance enhancing drugs as well.

Hormones don’t make you strong. MUSCLES make you strong. Men tend to have more, yes because of hormones. If you ask why that is well it’s because that’s the way men and women evolved. Men who were stronger reproduced more and that’s it.

Edit: if your answer has the phrase “sexual dimorphism” in it then you have missed the point of the sub…

Human sexual dimorphism. Men are built different, usually much larger. More, larger muscle [fibers](https://pubmed.ncbi.nlm.nih.gov/8477683/) and a larger [cross section](https://link.springer.com/article/10.1007/BF00235103) of muscle fibers. As well as differences in hormones. Height and weight differences can only explain about [half](https://journals.physiology.org/doi/full/10.1152/jappl.2000.89.1.81) of the differences in strength between males and females. Essentially men evolved to be violent and strong, women evolved to have babies. (I’m not making a moral or social issue case here, simply pointing out what biology says). Men are not only usually larger but they employ their muscles in a more efficient manner (at least for speed and strength, women win the endurance game generally).

The keyword to answer the question is sexual dimorphism, the differences in appearance (and consecuently muscle distribution) between males and females of a species.

It is a result of our evolutionary trajectory. As a mammal species, our female ancestors ALWAYS sought to breed and please the strongest male available (usually the alpha, leader of the group) to ensure her, and her offspring would be taken care of.

So in consecuence, if a male was not strong enough to secure his place as an alpha within a group (males often switched groups), he would never reproduce, and his (“weak”) genes would never be passed on.

Females did not have this problem, as alpha males would quickly impregnate ANY female within reproductive age, so most females, even the ones with genes that coded for lower body strenght would get to reproduce, competition was not nearly as hard as it was for males seeking to become alphas.

Therefore as time passed, newer generations in our species showed increased muscle mass (especially upper body strenght) and high desire to achieve dominance in males, while females kept being progressively more tame, more suited to nurturing and had considerably less upper body strenght.

Some people will inevitably feel offended by what I wrote above, and I can understand it from people who do not have a firm grasp of evolutionary biology. But I hope that once you delve deeper into the subject, you will understand why there is nothing wrong with it, and understanding our roots can actually help us move forward.

> some (most in my experience) women who are considered at peak fitness levels are still weaker than men who are in average shape

Yeah that’s subjective as hell….I’ve never seen a woman “at peak fitness” who’s weaker than “men in average shape”. Both men and women have a lot of levels of fitness they can be in, if you average that all out the average man will be stronger than the average woman….but a woman in great shape will almost always be overall stronger than the average man.

There is, however, some room for gender roles to appear here….in that many women are afraid to appear big and strong because they think they shouldn’t appear that way because they’re women. This causes them to sort of plateau at a lower amount of weight capable of being lifted by many men (likely not lower than the “average man” though).

Like if you’re looking at the gym and taking that as the “average male” then yeah, they are likely *above* average, which makes it harder for a fit female to compete with (but not impossible). Alternatively though there are *definitely* women who are well above the strength of the average male, being beaten out in raw strength only by similarly fit males. Just for a quick example, the current recognized strongest female has squatted ~850lbs, bench pressed ~600 lbs, and deadlifted ~690 lbs….how many average males do you know that can do even half of that? Personally? I only know a small handful of fit males that are anywhere near that level of weight.

There’s also a big difference between magazine cover “fit female” and power lifting “fit female”.

A toy designer makes two model robots. In type 1 he puts stronger engines, and larger frames, in type 2 he puts more flexible parts. One is made to hit and lift heavy stuff, the other is made to precisely and gently do things which need a soft touch. Both are fantastic equally but are not identical.

In general, men are designed with more muscle and a larger and stronger bone build. This resulting in more strength output. Women are designed with more flexibility in connective tissue. Testosterone, growth at puberty, height, and other factors play a large part. There are exceptions but average body types find these to be true.

This can be seen in sports on a competitive level in table tennis for example. The playing style at top level relies greatly on a powerful finishing move based on strength. That can only be countered with another finishing move. Hence making it difficult for a woman to return the counter and making the top people men.

Why were they like that? It’s part of the design from the God who made us. Man made is to do the heavy labour, while woman are better are things which need a caring, gentle touch, such as nurturing a child. Both are fantastic equally but are not identical.

They don’t. Everybody is exactly the same all the time. Anybody who says differently is evil and must be cancelled.