how do parents pass their genetic running abilities to their offspring?

Bad Wigins wrote:

Genotype determining athletic ability is bollocks until scientists spend 30 years studying athletes from birth to 30 under controlled conditions, which they won't.

What matters is development. Everyone has the genes to develop great athletic ability if those genes are expressed at the right time. That gene expression is a response to environmental stress. In distance running, the best adaptation is to be skinny and willowy - small wonder that the Horn of African countries Kenya, Ethiopia, Somalia and Eritrea produce the best distance runners. All of them rank in the bottom 15 countries in the world for per-capita caloric intake.

Japan ranks very low too, but not as low as the Horn of Africa, and not surprisingly has very good but not quite as good distance runners. The United States ranks #1 for calorie consumption and has only one native world elite distance runner, unless you count Flanagan.

In sprints, the opposite is true - mesomorphism and big muscles rule. Wanna grow big, eat. So there are plenty of sprinters in the USA and prosperous Caribbean countries. Growing up in hot weather (like in the south) is a developmental plus because you'll adapt to short-duration, explosive exercise that won't overheat you. Being poor is also a plus because making money as an athlete is a long shot that appeals more to poor people. A large proportion of the poor people of the US south happen to be black. Of course some people babble about how west African DNA makes them faster, but the west Africans themselves are no faster than the Europeans, despite having a lot more of that supposedly fast DNA.

There are so many genes relevant to athletics that it's like a bridge hand where everyone has hundreds or thousands of cards. With that many cards in play, extreme outliers i.e. "winning" hands are highly unlikely. It all depends on how the cards fall.

Bad Wigins wrote:

Genotype determining athletic ability is bollocks until scientists spend 30 years studying athletes from birth to 30 under controlled conditions, which they won't.

What matters is development. Everyone has the genes to develop great athletic ability if those genes are expressed at the right time. That gene expression is a response to environmental stress. In distance running, the best adaptation is to be skinny and willowy - small wonder that the Horn of African countries Kenya, Ethiopia, Somalia and Eritrea produce the best distance runners. All of them rank in the bottom 15 countries in the world for per-capita caloric intake.

Japan ranks very low too, but not as low as the Horn of Africa, and not surprisingly has very good but not quite as good distance runners. The United States ranks #1 for calorie consumption and has only one native world elite distance runner, unless you count Flanagan.

In sprints, the opposite is true - mesomorphism and big muscles rule. Wanna grow big, eat. So there are plenty of sprinters in the USA and prosperous Caribbean countries. Growing up in hot weather (like in the south) is a developmental plus because you'll adapt to short-duration, explosive exercise that won't overheat you. Being poor is also a plus because making money as an athlete is a long shot that appeals more to poor people. A large proportion of the poor people of the US south happen to be black. Of course some people babble about how west African DNA makes them faster, but the west Africans themselves are no faster than the Europeans, despite having a lot more of that supposedly fast DNA.

There are so many genes relevant to athletics that it's like a bridge hand where everyone has hundreds or thousands of cards. With that many cards in play, extreme outliers i.e. "winning" hands are highly unlikely. It all depends on how the cards fall.

mileage_man wrote:

Bad Wigins wrote:

There are so many genes relevant to athletics that it's like a bridge hand where everyone has hundreds or thousands of cards. With that many cards in play, extreme outliers i.e. "winning" hands" are highly unlikely. It all depends on how the cards fall.

Most of your post sounded very reasonable to my untrained ears, but this analogy seems misleading. For example, there are many genes that affect height, and yet even in a controlled environment heights would not be uniform (height is 60-80% heritable). The reason this is statistically possible is that while many genes affect height, there are a smaller number whose effects dominate. To extend your analogy, this would be like a hand of many cards, but mostly what matters is how many aces you have.

Things seem murkier when it comes to athletic performance. But for example, body type, VO2max, and muscular strength and endurance are all moderately to highly heritable. Here is a relevant quote from a review article I found (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3993978/):

"The heritability of a trait is generally considered an estimation of the importance of genetic factors to that trait. For example, the heritability of athletic status (regardless of sport) is estimated to be 66% (4). Height, which is critical for success in some sports, is highly heritable, with about 80% of the variation due to genetic factors (5). Body type (having mesomorphic or ectomorphic somatotype) is also highly heritable (6). These somatotypes are classically associated with power or endurance athlete status, respectively (7).

Costa et al. (8) recently reviewed existing family and twin studies related to specific endurance and muscular strength phenotypes. Aerobic endurance, as reflected by VO2max has a heritability of about 50% (9). Heritability estimates for muscular strength, and power range from 30 to 83%, depending on the specific muscle and type of contraction (8)."

That review article goes on to talk about specific genes, but while most of that was over my head it basically sounds like while we've found a couple genes that are correlated with performance, we're just scratching the surface of a very complicated system.

mileage_man wrote:

Most of your post sounded very reasonable to my untrained ears, but this analogy seems misleading. For example, there are many genes that affect height, and yet even in a controlled environment heights would not be uniform (height is 60-80% heritable). The reason this is statistically possible is that while many genes affect height, there are a smaller number whose effects dominate. To extend your analogy, this would be like a hand of many cards, but mostly what matters is how many aces you have.

"The heritability of a trait is generally considered an estimation of the importance of genetic factors to that trait. For example, the heritability of athletic status (regardless of sport) is estimated to be 66% (4). Height, which is critical for success in some sports, is highly heritable, with about 80% of the variation due to genetic factors (5). Body type (having mesomorphic or ectomorphic somatotype) is also highly heritable (6). These somatotypes are classically associated with power or endurance athlete status, respectively (7).