“Human body temperature has fallen over 200 years, and the reason is the decrease in physical activity”

Compared to the average human body temperature recorded 200 years ago, a study found that the modern human body temperature is 0.59 degrees Celsius lower for men and 0.32 degrees Celsius lower for women than 100 years ago. The researchers point out that the hypothermia conundrum does not lie in decreased physical activity.

In January 2020, a study was published that compared the average human body temperature during the Civil War in the 1860s with the results of the American National Health Survey, which began in the 1970s. Among them, the average human body temperature is decreasing, so the researcher speculates that the cause is the decrease in chronic infections that cause body temperature rise due to the rise of modern medicine.

Moreover, as a result of a survey of indigenous people living in Bolivia in late 2020, it was found that the average body temperature was dropping by 05 degrees to just 16 years. It turns out that a drop in body temperature is not unique to the United States and requires further investigation, as clearly sanitation is not due to improved health care.

A Harvard University research team hypothesized that the decrease in average body temperature was caused by a decrease in metabolism, that is, a decrease in physical activity, and started an investigation. Since the widely used method of recording physical activity in modern times did not exist 100 years ago, the research team analyzed the relationship between physical activity and body temperature by modeling changes in physical activity and metabolic body temperature.

According to calculations, it has been found that the male metabolic rate has decreased by 6% since the 1820s. Because this was equivalent to that of a 75 kg man who did 27 minutes of light running a day, the researchers concluded that modern humans spent an average of 30 minutes less in physical activity compared to 200 years ago, which may have contributed to the decrease in body temperature.

Researchers say that better health may have reduced the need to regulate body temperature, and understanding how much lower the need for thermoregulation could help understand how increased rates of chronic diseases such as heart disease and Alzheimer’s are related to physical activity. said. Related information can be found here.