Colour me black - Athletic success is skin deep

published:
Wednesday | November 15, 2006

Eulalee Thompson

Talented
black people seem to have an edge over other racial groups in a wide
range of athletic activities requiring speed and power.

This issue preoccupied the mind of Professor Errol Morrison, president and chief executive officer of Blue Cross of Jamaica (on leave from the position of dean, School for Graduate Studies
and Research, University of the West Indies), when he teamed up with
Patrick Cooper, Jamaican journalist and businessman, now living in the
United States to do research.

Physical
characteristics, peculiar to black people as a result of their
evolution and interface in a tropical environment, the sickle-cell
trait and malaria were some of the factors they found, almost acting in consort, to produce a disproportionate number of successful black athletes over the decades.

Their viewpoint, presented in an essay published in the recent issue of the West Indian Medical Journal 2006; 55(3):
205, places a positive twist on the sickle-cell trait, a condition
which people of African origin seem more predisposed to develop and
malaria, an infectious disease transmitted by the Anopheles mosquito, primarily in tropical and sub-tropical regions.

Sickle-shaped cells

( L - R ) Simpson and Powell

The
development of sickle-shaped blood cells (relative to sickle-cell trait
and disease) is apparently the body's way of protecting itself against
the parasites linked to the development of malaria. Sickle-shaped blood
cells are not as 'welcoming' as normally-shaped red blood cells to the
malaria germs.

You
may now be wondering, 'so what's the link to between sickled cells and
athletic prowess?' The link lies somewhere in the use of oxygen. One
would imagine that sickle-shaped cells would compromise the amount of
oxygen available to black athletes wanting to perform at the top levels
of their profession.

However,
Morrison and Cooper, quoting from elaborate studies conducted on
Olympic athletes from the 1968 Games in Mexico City, find that there
are 'compensatory mechanisms' developed by the body to take care of
these deficiencies in oxygen intake and use. Some of these
'compensatory mechanisms' relate to differences in the composition and
activity of muscle fibres found in black people when compared to other
racial groups. Black people have a higher percentage of fast-twitch
fibres and lower levels of slow-twitch fibres than white people. This
composition of black muscles is linked to a more rapid conversion of
glucose into energy than in white muscles.

One
of the studies conducted by Claude Bouchard, geneticist and exercise
physiologist, and Jean-Aime Simoneau, exercise biochemist (published
1990), concludes that "the racial differences observed between Africans
and Caucasians in fibre type proportion and enzyme activities ... may
well result from inherited variation. These data suggest that sedentary
male black individuals are, in terms of muscle characteristics, well
endowed for sports events of short duration."

Longer arms and legs

Other
studies point to differences in the lung activities that impact
athletic prowess in black people. Lung volume among white subjects, for
example, was 10 to 15 per cent greater than in their black counterpart
but differences in breathing patterns during exercise and the fact that
black subjects consumed more oxygen at every phase of exercising made
for more powerful performances.

Morrison
and Cooper also point to differences in body type and body proportions
that impacted athletic performance. People of African descent have less
fat under their skin, narrower hips, longer arms and legs and shorter
trunks than other racial groups. These biomechanical advantages, they
say, "influence power-to-weight ratio and stride length."

what do you think?

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