- Generally, it is easier for men to develop not just upper-body strength, but strength in any body part, compared to women, because they have more testosterone.
- However, in the modern world, personal upper-body strength is becoming irrelevant to payoffs from economic policies.
It is widely proven that, on average, men are physically stronger than women. A big part of that strength lies in the upper-body muscles.
However, a study by scientists from Harvard and Moi universities shows that traditional chores thrust on women are forcing them to develop rare upper-trunk strength.
In some communities, they are even stronger than men.
The scientists demonstrated that among the Kalenjin, rural women are the strongest people in the community, physically stronger than the rural men.
“We specifically compared men and women from an urban community with professions that do not involve manual labour with rural subsistence farmers, including women who frequently carry heavy loads,” they said.
They sampled 74 Kalenjin adults aged 18-61, with females being on average 35 years and males 39 years.
The 74 were subjected to trunk muscle endurance and strength tests, while muscle flexibility was measured with exercise tests and electromyography (which records the electrical activity produced by skeletal muscles).
“Rural women had higher trunk extensor and flexor endurance than rural men,” authors say in the study published in the American Journal of Human Biology on May 14.
A flexor muscle is the muscle that bends a joint, whereas an extensor muscle straightens a joint.
“Urban women had lower trunk flexor and extensor endurance than urban men,” they added.
Both urban women and men were also weaker compared to the rural women, the study shows.
Generally, it is easier for men to develop not just upper-body strength, but strength in any body part, compared to women, because they have more testosterone.
However, women who deliberately engage in endurance training can grow as much muscles as men.
The researchers looked for an explanation why rural Kalenjin women were stronger. They attributed it to the traditional gender roles that often disadvantage rural women in society.
“High levels of physical activity among nonindustrial subsistence farmers, particularly head carrying among women, appear to be associated with high trunk muscle endurance and strength, which may have important benefits for helping maintain musculoskeletal health,” they said.
The study is titled ‘Trunk muscle endurance, strength and flexibility in rural subsistence farmers and urban industrialised adults in western Kenya’.
Other institutions involved in the study are US's University at Buffalo, Rwanda's University of Global Health Equity, and Pemja Primary School.
In most species on earth—such as insects, fish and birds of prey—it is actually females that are larger and stronger than males, because they carry thousands of eggs in their bodies at once.
But most land-dwelling vertebrates, including human beings, are exceptions to this rule.
Over the millennia of evolution, men have used their gender’s greater capacity for physical power as justification for self-entitled to power against women, scientists say.
“In studies conducted in Argentina, Denmark, and the United States, men with greater upper-body strength more strongly endorsed the self-beneficial position,” said five scientists in a separate study published in the Psychological Journal.
However, in the modern world, personal upper-body strength is becoming irrelevant to payoffs from economic policies.
The scientists said people with good musculoskeletal health can carry out the activities they want to with ease and without discomfort.
The Moi University scientists explained why they carried out their study.
They said high muscle endurance, and strength help maintain musculoskeletal health. But there is evidence for tradeoffs among people in rural and urban centres.
The study was carried out to test if these observations extend similarly to both men and women in rural and urban environments.
-Edited by SKanyara