Why do Europeans and Africans tend to find it easier to get an athletic build than most Asians?

 Because they are more genetically blessed than us Asians.

As we know, there are 3 kinds of somatotypes (body shape and human physical characteristics):

• Ectomorph
• Body, arms and legs thin. Relatively small bone structure
• Don't have much muscle
• Difficult to gain weight
• High metabolism, the body burns calories quickly
• Mesomorph
• Athletic body, relatively large bone structure
• Hard body, has more muscles than ectomorph
• It is easier for the body to store fat than ectomorphs
• The body responds better to weight training (the body is easier to build muscle)
• Endomorph
• The body is solid but tends to be soft and bubbly , the arms and legs are big
• The body has strong muscles, especially in the legs
• The body easily builds muscle and stores fat
• Slow metabolism so easy to gain weight

The somatotypes in the diagram below are further divided into 7 types, because there are very few people who are pure ectomorphs, pure mesomorphs, or pure endomorphs. Often a person's physical type is in between 2 somatotypes, for example ecto-mesomorph, endo-mesomorph, and so on.

There are many articles explaining the differences in human somatotypes based on their ethnicity. I include an article whose explanation is quite clear and concise, and contains a summary of several scientific references.

Important points raised in the article above:

• People from West Africa have the most mesomorphic body type.
• Their bodies have more type II muscle fibers high-power (but low-endurance)
• Therefore they master sports that require explosive power, such as sprinting (short distance running).
• People from East Africa have the most ectomorphic body type.
• Their bodies have more type I muscle fibers that don't produce a lot of power (but have high endurance).
• Because of that they master sports that require high endurance, such as running a marathon.
• Europeans are more endomorphic than West and East Africans, but not as endomorphic as East Asians.
• They have a strong upper body, broad shoulders, a longer and more muscular torso, and shorter legs and arms than Africans.
• They have more Type I muscle fibers than Africans, so they dominate high-energy sports like powerlifting.
• World's Strongest Man dominated by Europeans, especially people from the Nordic countries.
• East Asians are more endomorphic than Europeans and Africans.
• Also more endomorphic than people from Southeast Asia and Central Asia.

From the explanation above, it seems quite clear why Europeans and Africans tend to form an athletic body more easily than Asians.