Often times, we see athletes touted as genetically gifted. It is said they come from an athletic family and are predisposed for success. On the flip side, we see people who will blame their poor genetics for failure or act as if they're completely genetically bankrupt and built every stitch of what they had out of hard work. The purpose of this article is to examine how heredity and other factors contribute to athletic success and what traits are highly related.

Sports families

To go with the most simplistic view, let’s take a look at a few sports families. This isn't necessarily the most reliable form of assessing heredity because these cases aren't regular occurrences. However, it has been noted that high level (Olympic and professional) athletes usually have parents who are more developed than the general population with some experience in sport.

Here are a few examples:

Vyacheslav Klokov Father Weightlifter (heavy weight), USSR; set seven world records, held one gold and two silver medals
Dmitry Klokov Son Weightlifter (105 kg), Russia; holds a silver in the Olympics and one gold, two silver, and two bronze in world championships
Milan Janics Father Kayaking, Yugoslavia; world champion in 1978, 1979, and 1982; silver medalist at 1984 Olympics
Natasha Janics Daughter Kayaking, Hungary; world champion 2002–2007; two-fold Olympic champion in 2004 and Olympic champion in 2008
Matty Alou Brother Played outfield for MLB with extended career in the majors
Jesus Alou Brother Played outfield for MLB with extended career in the majors
Felipe Alou Brother Played first base for MLB with extended career in the majors
Moises Alou Son of Felipe Alou Had extended career that spanned nearly two decades in the majors; six-time All-Star, world series champion, two-time Silver Slugger, and Babe Ruth award winner
Archie Manning Father NFL quarterback who had 13-year career with two pro bowls, one all-pro selection, and an NFL Offensive Player of the Year award
Payton Manning Son NFL quarterback with a laundry list of achievements that would take up a lot of space to list
Eli Manning Son NFL quarterback with a list that is nearly as long as his brother, albeit more Super Bowls
Cooper Manning Son Former Division I receiver (aka “the Manning no one cares about”—that is a joke, so hopefully Cooper Manning fans don’t get their panties in a wad)

While using talented parents as a sole method for determining whether offspring will be talented in sport isn't warranted, it is hard to ignore that many high level athletes have parents who were accomplished in sport. This can be due to both genetic factors but also environmental factors as well. This will be covered in further detail in the following sections.

Genetic influence on somatotype

Somatotype is the combination of length, width, muscle mass, and fat. Genetics play a large part in certain dimensions of this, but in others, it isn't as strong.

Studies have been performed (1) demonstrating that:

  • Body lengths (height, length of limbs, and length of feet) have the strongest influence from genetics with a 70 percent level of inheritance observed.
  • Body width is also strongly correlated to genetics with a 50 percent level of inheritance observed.
  • Muscle mass has a somewhat lower correlation with only a 40 percent level of inheritance observed.
  • Body fat has the lowest level of inheritance with only a 20–30 percent level of inheritance observed.

So what does all this mean? First, there is some truth to the old “you should have picked better parents” line in regards to certain traits. If everyone in your family is short—and this is the case going all the way back to your ancestors—most likely you will be short. The same goes for your width. However, you have a greater chance of adding on some muscle and not being a complete fat ass. This goes to show that the old “I’m fat because my family is fat” yarn is most likely not as much a factor of genetics as it is an environmental one. This means that while fat parents may have fat kids, it is probably more a factor of eating fast food and other crap three times a day  every day.

Before anyone says “I know a guy who is six feet, eight inches and jacked as shit, but no one in his family is tall or large,” remember that there is the outside chance of this happening as the percentages show. This means this person got lucky in the game of genetic Russian roulette and found the empty chamber.

Genetics and motor ability

Similar to somatotype, genetics play a large role in certain motor abilities, but in others, they may not be as much of a factor. While these abilities are more trainable than the somatic traits, there still is a predisposition that can lead to success in certain disciplines.

A similar study was done (1) that shows the level of correlation of genetics. However, I won't list every single trait. Instead, I'll summarize. In the study, alactic anaerobic power has been shown to have the greatest level of inheritance (70–80 percent). This means that the ability to sprint, jump, and throw explosively has a strong genetic base. If someone comes from a long line of slow, non-explosive people, this means he'll be limited in events such as sprinting, jumping, and shot put. This ability can be improved, but it all has a genetic starting point that will limit the amount of improvement. Conversely, aerobic power (Vo2 max) and maximum isometric strength have a much more positive outlook, being tied to only 20–30 percent of genetic influences. So the endurance and slow strength (i.e. powerlifting) events are less tied in with how bad previous family members may have been at them, and you will be able to make more progress in these areas. Somewhere in the middle lies abilities such as coordination, flexibility, strength endurance, and so on.

Again, there will always be outliers in every aspect, but it has been shown time and time again that certain traits are strongly influenced by heredity. The played out, “You can’t coach speed” line is true to a certain extent (when we're talking about the actual ability, not correcting technical errors or programming).

Environmental factors

As was listed earlier, environmental factors are the missing variable. While some factors are definitely determined by inheritance, they'll appear in conjunction with other things such as diet, lifestyle, rest, proper coaching, and so on.

When we look at the aforementioned sports families, on one hand, we could strictly attribute their success to genetics. However, this would be incorrect. Genetics play a role in very simple manifestations of the motor abilities. Responses to training and the ability to use the motor abilities are specific to the event. This is where coaching and proper technique come into play. It isn’t as if the Alous family came out of the womb swinging a bat. The Klokovs weren't cleaning and snatching as infants, and the Mannings weren't throwing perfect passes as toddlers.

Diet plays a big role in body fat and muscle mass. Most likely, if someone eats shit all day long, he will get fat. Sure, genetics play into this and there are the small percentage of people who can stay lean eating candy and cheeseburgers three times a day, but this isn’t the norm. Conversely, there are guys who get massive eating far fewer calories, but they are the outliers that hit the genetic lottery.

It's important to look at more than just one parent or family member on the subject of genetics. All too often, people will say, “I have terrible genetics! I worked so hard for everything I accomplished! Just look at my parents!” The problem is these people are looking at time in a vacuum and not thinking about what the parent may have looked like earlier in life or what choices (i.e. environmental factors) he may have made that contributed to him being fat, weak, or out of shape. If the family member never did anything physical, ate like crap, drank, and abused drugs regularly, you're observing the environmental factors at play.

Now, say the offspring does everything right in a training sense and has outstanding results. He could argue that he really was genetically bankrupt. Personally, one thing I can’t stand is someone throwing a fit over how bad his genetics are and how hard he worked. People like this also seem to get insulted if anyone says they had good genetics. It isn’t as if someone is implying that they ate cake and candy all day, sat around playing video games, and were better than everyone at their given sport. If we are to look at the sport families listed above, would anyone truly believe they didn’t work hard? It wouldn’t matter how skilled their bloodline was if they didn’t become somewhat competent in their given craft.


When looking at the subject of heredity, it's important to understand that some aspects are strongly correlated and others have less bearing. While some aspects of somatotype may be strongly influenced, others can be controlled through training and diet. The same goes for motor abilities. Certain aspects may only respond to training at marginal levels whereas others can be increased. Finally, it's important to not have tunnel vision when assessing your own genetic shortcomings or gifts.


  1. Issurin V (2008) Principles and Basics of Advanced Athletic Training. Ultimate Athlete Concepts: Michigan.