[Lewis Thomson (OP)]

Listener John has written into The Naked Scientists to find the answer to this question.

"Hi, so I was having a conversation with my friend about race and identity. We got onto physiology and my friend mentioned how it appeared that different ethnic groups appeared to be better at certain sports, for example Kenyans are typically hailed as greater runners. He then said that he thinks it's because black people are stronger and are able to develop more muscle than other races. I tried looking into this because I wasn't sure if this was true or just a racial stereotype given that black people, especially black men, are wrongly characterised as larger and more intimidating. However, I couldn't find a conclusive answer. Is there any truth to what my friend said?"

Discuss your answers in the comments below...

[Origin]

On average there is no difference, however at the elite level (the tail of the population) there certainly appears to be a difference.

[alancalverd]

Some time ago I recall reading about the pivot length of the calcaneum giving some advantage to East Africans in distance running, but I suspect that cultural differences are more significant than anything else. Face it, most proper sports were developed and codified in Britain but most medals and competitions are won by Australians and New Zealanders.

[Halc]

Kenyans are better at running because they live in Kenya, not because of their race.
A great percentage of the country is at significantly high altitude and the people who grew up there (for generations) are used to breathing thin air. They develop/evolve better lung capacity, as would any race put there for generations. Lung capacity spells stamina in distance races.
Ditto with the Sherpas who don't need bottled oxygen to reach the summit of Everest. They don't get appendicitis nearly as easily as people bred at low altitude.
My brother moved to an altitude of about 10000 m, and sure enough, within a few years, out went the appendix. He wasn't bred for those altitudes.

[evan_au]

Some ethnic groups (like Kenyans) that have produced amazing runners live in an environment where cars were rare (as were shoes), so running barefoot was the normal mode of transport. They also live at high altitude, so there may be genetic or epigenetic factors that lead to increased blood oxygenation.

Perhaps as cars (and shoes) become more common in those areas, their natural advantage will be unnaturally eroded?

Oops! Overlap with Halc...

[alancalverd]

My brother moved to an altitude of about 10000 m

Not on this planet, surely (Everest - 8,850 m)?    Plenty of folk live at 1000m above sea level but chronic oxygen depletion begins at 2000m. That said, "lowland" athletes frequently train at altitude to improve their oxygen-carrying capacity for a competition. Short stature (hence faster circulation) seems to be a characteristic of mountain peoples, who might struggle to keep up with longer legs at low altitude.

Lung tidal volume is significant for sprinting and middle-distance running but the limiting factor beyond 1500 meters is heat dissipation. "Tall and skinny" wins the aerobic, isothermal marathon because he has a larger surface to volume ratio than a weightlifter or ruggerbugger who could beat him in an anaerobic, adiabatic 100m.

Swimming is different! Excessive heat loss becomes a problem in marathon events, so whilst sprint swimmers  look much like sprint runners, endurance swimmers carry a bit more fat.

So race is indeed important in racing. Whilst the extremes overlap, the median body shape and height of different human groups does indeed differ even under controlled diet and exercise conditions so you are more likely to find a marathon champion among East Africans than any other group.

[syhprum]

The superiority of black Americans in many sports can be attributed to the selective breeding of black slaves for their physical prowess.