The human race is divided into two variants: male and female. The former is generally more dominant physically due to its size, making them bigger, stronger, and faster. They are predisposed to being better fighters and athletes. Recognizing this, major sports (football, basketball, soccer, etc) are usually sex-segregated, with male and female leagues playing amongst themselves rather than competing against each other.

This species has reached a point where genetic engineering can modify the human form. People can upgrade themselves physically to make their bodies stronger, faster, and tougher than naturally possible. For this world, I need both men's and women's major leagues to unite under one banner. Males and females now compete with each other in the same sports, with various leagues now including both sexes in competitions.

However, there is a problem I can't seem to solve. Even with genetic therapy, male athletes would still remain dominant. Since men are already physically more powerful, enhancements will simply act on what is there already. In a contest between two athletes from each sex having access to the same enhancements, the man is still likely to benefit more from having a better base form.

Is there a way I can make genetic engineering avoid this so as to put these athletes on more equal footing?

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – L.Dutch
    Commented Feb 14, 2019 at 10:43

7 Answers 7


Once the natural abilities of the average human have been entirely and routinely overwritten by genetic modification then what changes for the Olympics isn't the people, it's the sport.

There are already events where men and women compete together and sometimes even age is no longer a major factor. Specific examples include the equestrian events, where the rider's sex or age are largely secondary to their abilities and training of the horse. You'd also see more focus on things like the judged dance events like ice skating and rhythm gymnastics where pure strength and stamina are secondary to other abilities. You might also see a shift towards team sports where the ability of the group to coordinate along with specific skills that can't be genetically coded for take precedence. Yes strength, stamina, agility etc are still aspects in these events, but they're less the primary aspects compared to say, the hammer throw.

The further the events move from straight physical ability towards training, skill, timing, communication, and poise, the more equally men and women compete together.

Once upon a time poetry and dog grooming were Olympic events, they were only dropped because they could be done professionally and the Olympics was fundamentally about being an amateur, things change, they can change again.


You underestimate just how wide genetic modifications can be. The differences between males and females are the side effect of a few hormonal differences and a lifetime of social shaping. People disagree how much is hormonal and how much is societal, but we all agree that those are the major differences to consider. Obviously you have control over the societal changes, so the only question is how much can you control the hormonal ones. Hormones are a big deal in the body. Genetically female individuals who take testosterone supplements gain substantial muscle mass and strength. Genetically male individuals who take estrogen supplements and testosterone blockers lose muscle mass and strength.

So really, your males and females are just operating with different levels of these hormones. But the ranges which can be supported are limited. You can only have so much testosterone in your body before the other effects start to have a dramatic and detrimental effect on your body. The body was always designed to operate in a balance.

But you're talking genetic engineering. You've got more room to play than anyone before you. Your real limits will not be sex based, but physics based.

Let's use a metaphor. Cars.

Toyota SupraFord Mustang

The top car is a Toyota Supra. The bottom is a Ford Mustang. Both are recognized to be decent street racing cars. The Mustang has roughly 100 more HP than the Supra, so in a straight on muscle fight, the Mustang is going to have an advantage. A modern Mustang can edge out a Supra on the quarter mile.

But we're talking genetic engineering. Let's talk modifications! Thanks to Ynneadwraith's wonderfully helpful comments below, I'm now somewhat versed in the mods which can be applied to these vehicles. It turns out that the Supra was quite overengineered in many places. A Supra's stock gearbox can deliver 450 ft-lbs, while the Mustang's was only designed for 384 ft-lbs. This means that as you engineer bigger and bigger engines, the Mustang actually starts to break down earlier than the Supra. Without making drivetrain mods, you could actually put more torque on he pavement in a Supra, despite it initially having the weaker engine. So who knows, perhaps the female form is actually capable of being moded more than the male form. (practically speaking, I do believe the female pelvis is actually a disadvantage. From what I've read, it's wider than the ideal walking/running size to support child birth. However, the jury is out about the rest of the body!)

But we're talking genetic engineering. We're not talking little tiny upgrades. You have access to the full gamut of human capacity! This is less of a "swap parts on the car to make it go faster." This is more like NASCAR. They're called "stock cars" because historically they had to be production models. However, they've been pushing the limits for a long time, and that whole "production model" thing has kind of gone by the wayside.

Here's a Toyota stock car, and a Ford stock car.

Toyota Stock CarFord Stock Car

Note that they call themselves a Toyota Camry and a Ford Fusion /gigglesnort/

By this level of engineering, the cars are almost completely identical. They may have started out as a Camry or a Fusion (really?!?!), but at this level, they have basically the same engine, same chassis, same transmission, same tires, same virtually everything. They aren't limited by their theoretical origins in production cars. They're limited by the physics of what a race car can do, and what NASCAR will let them do.

But you're talking genetic engineering. Where we're going, we don't need roads, though we might as well use them if we have them:

Jet Car

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    $\begingroup$ This is a great answer and basically what I was about to reply with. However you might consider a "Tl;dr" section because while the sports car comparison is apt you spent a lot more time talking about cars than you did the athletes. $\endgroup$ Commented Feb 13, 2019 at 4:51
  • $\begingroup$ I’ve long since held that high level sporting events should be categorised based on hormone levels. Sure, you’d get more men in the ‘high testosterone’ (or whatever criteria get used) category, but it would open the field for so many more interesting races. $\endgroup$
    – Joe Bloggs
    Commented Feb 13, 2019 at 7:11
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    $\begingroup$ Excellent answer, but of all the cars to choose for the 'less well built for power' option, that particular Supra is not the one. As standard, they're overbuilt to a degree not found in the Mustang so despite making 100hp less, they're capable of taking much more unmodified. The R154 gearbox in the Supra is rated at 450lb-ft, whereas the MT82 in the Mustang is rated at 382lb-ft. Both are realistically capable of far more than that, but it's an example that is played out throughout the drivetrain. Your point still stands, but the example could do with modification ;) $\endgroup$ Commented Feb 13, 2019 at 12:13
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    $\begingroup$ @Ynneadwraith Oh man, can I cite you as my source? I was afraid and thrilled by the idea of someone who actually knows something about modifying cars demonstrating how inadequate my knowledge was. WorldBuilding did not disappoint! $\endgroup$
    – Cort Ammon
    Commented Feb 13, 2019 at 18:44
  • $\begingroup$ @CortAmmon Haha if you like :) the rest of the example works perfectly, and I got a particular kick out of the gigglesnort at the 'ford fusion'. There's about as much Fusion in that car as there is in me... $\endgroup$ Commented Feb 13, 2019 at 23:21

Once you have been genetically modified to obtain the optimal form for a given sport, both males and females can participate together. Everyone will essentially appear the same and sports will devolve into a mental activity rather than a physical one since everyone will end up on the same physical level due to the genetic enhancements.

The only difference between athletes will be on paper. Team, country, birth gender. Everything else will be modified to be as optimal as possible and so differences between a male and female body will virtually disappear.

As a rough example. For running, everyone is going to look exactly the same as Usain Bolt. One person might try and be slightly taller, slightly thicker legs, slightly larger heart, but there would be a form that is considered optimal to get the maximum speed to endurance ratio for a 100m sprint and everyone would sit at that form. they would all have very similar bone structures, muscles structures and body chemistry to make sure they are literally the best you can possible achieve.

  • $\begingroup$ You didn't account for training. A lot of researchers peered on why Usain Bolt is so fast, and more than physic, technique play an important role. You can be as tough as you want, if you screw up your start, acceleration, way you land your feet, anything, you'll lose a few tenths of seconds. And in an Olympic race, tenth of a second is the difference between 2nd and 3rd runners. $\endgroup$
    – Nyakouai
    Commented Feb 14, 2019 at 9:31
  • $\begingroup$ @Nyakouai But its not the difference between the 1st and 2nd positions. Bolts records are faster than known and caught dopers. Not only is he also taller, he is much larger than many of the other sprinters. Everyone trains to get their body into the peak physical condition for the day of the race. Everyone trains to ensure that their running posture is optimal. But the difference between 2nd and 3rd runners compared to 1st (bolt) shows how much of a difference the body type can really account for. $\endgroup$
    – Shadowzee
    Commented Feb 15, 2019 at 0:18

As you commented under your question, genetic enhancements will likely eventually find their way into sports, simply because the downsides of being 'unenhanced' are just too great. However, this leads to the undesirable situation where sports will quickly collapse as the most optimally enhanced athletes will always win, no matter what. Instead of a (fairly) even competition, the real race is to enhance yourself the best so you can play better than everyone else. Sports aren't too fun this way.

However, to answer this question and yours, I propose this solution. Let's assume that genetic engineering will be constantly putting out available enhancement treatments to improve athletic abilities. Therefore, every year, or as necessary, a carefully reviewed list of acceptable 'base enhancements' will be released for the sport. Athletes are allowed to use any (or maybe a certain number) of enhancements at their choosing. Overpowered enhancements are pretty likely to be banned. In this way, a search for new enhancements will be avoided, as until reviewed, all new enhancements will be illegal, and only enhancements available to all athletes will be permitted.

Now, once we control the accepted enhancements for the sport, we can grant additional enhancements to female athletes. We can give them more muscle mass, bone density, or other improvements (I'm not really an expert). In this way, we can pretty significantly level the playing field between men and women, and pretty effectively combine both leagues.

  • $\begingroup$ There are many women who are naturally stronger and faster than many men. $\endgroup$ Commented Jun 26, 2019 at 2:00
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    $\begingroup$ @SabrineCrystalSantos , you are completely correct in that. However, on average, men tend to have around 1.5X more muscle mass than women. We're not comparing the traits of an individual here; we are dealing with the characteristics of a specific gender. $\endgroup$
    – Rafael
    Commented Jun 27, 2019 at 13:31

In our current world, the overlap between males and females is greater than the differences.

A great deal of the difference between male and female athletes is in training opportunities and encouragement. If 5% of boys try out for soccer and only 2% of girls do, you end up with fewer choices for top training as time goes on and teams whose talent isn't as deep.

Think about countries that (now or in the past) send people out to elementary schools to put large numbers of children into sports programs. Like gymnasts in the former Soviet Union or speed skaters in China. They pick those children with the physical characteristics that might predict greatness and give them excellent free training. Most drop out over time but the top level athletes that are left are more numerous than in countries that don't have such programs (the US is somewhat of an exception, but I digress).

If you give the same encouragement to girls as to boys, and if you have a lot of opportunities for affordable training in a variety of sports, you'll have lots of good athletes.

All that being said, yes, the average man is taller and stronger than the average woman. Top female Olympic athletes, for example, are better at their sports than nearly all the men in their field just, usually, not quite as good as the top male Olympic athletes.

One way to have mixed gender teams where the athletes are all up to the standards is to have different levels. We already do this. Baseball has the minor leagues (A, AA, AAA) and the major leagues. But this doesn't help if the pool of female athletes is smaller to begin with and it makes all the highest level teams nearly entirely male.

So start the enhancements early. Height, muscle size and distribution, and a few other relevant factors are dependent on hormones. Mostly those starting in puberty, though the ones from before puberty can change average heights and such a bit. Children who are transgender who start hormone treatments (both to add and to suppress) as puberty hits will end up with bodies very much like their real genders, not like their birth biology would have led them (I can't find the article that talks about how these siblings diverged in height and musculature, but this is a pointer.)

Since you're using genetic therapies and not just flooding someone's body with hormones and hormone suppressors, you won't be messing with their gender or gender-related characteristics. Instead you'll be taking people to a different place in the normal range of abilities people of their gender would have.

Plus a bit perhaps. How much is that extra bit? What is the ceiling on these enhancements? Since pre-pubescent boys in athletic programs will also get these treatments, their height and musculature will also increase. But both boys and girls may only increase to comparable levels, or levels where the differences don't matter as much (size does make a difference for many athletes, but it's not linear and not as exact as people might imagine).

Add in other genetic enhancements for adults who are competing at top levels. After all, it's not enough to be tall and strong. Different sports require different skills and different types of bodies. A great swimmer and a great mogul skier will not have the same bodies.

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    $\begingroup$ "Top female Olympic athletes, for example, are better at their sports than nearly all the men in their field just, usually, not quite as good as the top male Olympic athletes." Except that's who they're competing against, not the average man, or even average male athlete. Example: 69 kg class weightlifting. Women's record in the clean and jerk, 153 kg (2004), mens: 195 kg (2000). In the 2004 Olympics, in that weight class, Liu Chonhong's Olympic record would have been beaten by every male competitor, including the ones disqualified for 3 bad attempts. $\endgroup$ Commented Feb 13, 2019 at 4:43
  • $\begingroup$ @KeithMorrison weightlifting is a sport where there is more gender disparity for sure. There is more overlap elsewhere. Sometimes the top women on the US Olympic team, for example, are better than the top men for the same sport, because the women are in a higher level. Depends on the sport. Overall though, yes, the top women are not in metal contention, as they say. $\endgroup$
    – Cyn
    Commented Feb 13, 2019 at 5:35
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    $\begingroup$ This came up on skeptics a while back, in most directly comparable athletic events, the top woman would struggle to make it into the top 1000 men $\endgroup$
    – Separatrix
    Commented Feb 13, 2019 at 8:34
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    $\begingroup$ The point in that skeptic's thread that there are good odds that many, or even most, of the top athletes in a given sport don't even make it to the Olympics or world championships because of limits on how many per nation can attend is an important one. For instance, the US trials in track and field, for some events, is considered the most elite competition in the world. $\endgroup$ Commented Feb 13, 2019 at 10:03

With genetic modification you have control over everything, size, fat %, bone mass, muscle mass, lung capacity, response to stimuli (how much muscle you create for certain actions for example) etc. The only differences that remain are sexual differences.

Women have a uterus and ovaries that take up space. These reduce the maximum movement of your diafragm as they take up space that men dont have to spend on them and reduces their maximum lung volume.

Women also have breasts, I have already had a discussion with Cyn about it and I found that they can impede movement in certain cases (1). Breasts also add weight, and in top sport where it often depends on milliseconds who wins or reaches a world record this makes a lot of difference.

This might be preventable. We know that certain animals can have their species change sex, so it might be possible to "supress" the female sexual organs, keep them extremely small and inactive until the woman decides she is ready for children. It might take a while to adapt and grow the breasts, uterus and ovaries to a useable size but they wouldnt interfere with the woman's performance meaningfully.

Questions like these are often used for female equality discussions. I think that "female equality" is a misnomer, as it should be about "equality between women AND MEN". You cant ask for female equality without considering both. Most people seem to ignore that men are also different from women even in these discussions, and their sexual organs are just as much detrimental to their performance due to their dead weight and how they can impede movements. If only women were altered the women would surpass men in sports. Men would need to subject their dick and testicles to the same feature as the women their sexual organs, and only choose to grow them when they are ready for procreation.

1: https://www.google.com/amp/s/theweek.com/articles-amp/462246/breasts-impede-athletic-performance

  • $\begingroup$ Most female athletes are flat chested, so breasts aren`t a problem. $\endgroup$ Commented Jun 26, 2019 at 2:01
  • $\begingroup$ @SabrineCrystalSantos That is what the words "keep them extremely small and inactive" means. And even small breasts will still mean an extra layer of fat and tissue on the chest that isn't supporting the athletic performance. Same with the male genitals, they shouldn't be there until the sportsman wants it. It would allow them to participate in predominantly female sports like turning. $\endgroup$
    – Demigan
    Commented Jun 27, 2019 at 15:27

From your question: "For this world, I need both men's and women's major leagues to unite under one banner. Males and females now compete with each other in the same sports, with various leagues now including both sexes in competitions."

Depending on what kind of story you are writing, you do not need genetic engineering to accomplish this. This is already starting to happen in our modern world without genetic engineering whatsoever, largely for reasons related to current gender politics more than anything else. All you need to do is have your society decide to abandon this particular point of distinction between men and women.

Right now, there is at least one prominent case of a transgender girl (e.g. people who were born male) competing in female wrestling at the high school level. This is highly controversial because this person is winning a lot, effectively because it subverts the very sex segregation you mention in the question. One way of resolving that controversy might be to simply not have a boys and a girls league anymore because it's too hard to come to a social agreement on who is male and who is female, e.g. who should be segregated from which league and how.

These questions don't only arise out of transgender issues. I seem to remember there have been controversial cases at the Olympics where women who have unusually high levels of testosterone were disqualified from play in female leagues despite the fact that they were born women.

I mean yes, you could point out that differences still exist between genders and therefore the results of certain sporting events will therefore be lopsided in favor of men even if the league makes no distinction between men and women. Depending on what kind of story you are writing (e.g., why you need this sports league in your plot), you can leave that as an unresolved problem, or as not-a-problem (e.g. there is a new social consensus that is OK with potentially lopsided results for whatever reason).


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