Why Are We So Tired?
This data is interesting, but it leaves us with a tricky puzzle: if we’re getting more sleep than we used to in pre-industrial times, why do we experience such chronic fatigue? Here are some possible ways to explain why we’re so much more tired than hunter-gatherers.
“Lies, D****d Lies, and Statistics”
Part of the explanation is that the BLS numbers don’t tell the whole story. Although the numbers are considered valid for what they are, they don’t really track sleep hours. Instead, they track hours spent sleeping, including naps and time people spend awake in bed trying to sleep. Notably, a mattress company survey reported that people slept only an average of 5.5 hours a night in 2019. The real number is likely somewhere between the two values, telling us that we might not sleep much more than hunter-gatherers, but we probably don’t sleep much less.
When you have diabetes, your body has difficulty maintaining healthy blood sugar levels. Either the body doesn’t produce enough of the hormone insulin, or your body doesn’t use it efficiently. People with diabetes often experience chronic fatigue. We’re not entirely sure how the two connect, but the body’s inability to utilize sugar properly could contribute to feelings of chronic fatigue.
Diabetes is rare among pre-industrial peoples. Diabetes risk is closely linked to obesity. None of the tribal peoples are obese: their body mass index (BMI) ranges from 18 to 26, while obesity is BMI 30+. For comparison, over 30% of people in the Detroit area are obese. Nearly 10% of Americans have diabetes.
Depression is characterized by chronic low mood, low energy, and poor sleep. People with depression tend to feel sad, lose interest in things they used to enjoy, may feel worthless, and may focus on suicide or death.
About 5% of the adult US population suffers from depression. If you think you might be depressed, talk to your doctor, but note that your symptoms of depression might be traced to other causes.
Lack of Exercise and Play
If you aren’t getting enough exercise, it can decrease your overall energy, contributing to chronic fatigue. While Americans have an average of about 5.5 hours of leisure time each day, they don’t spend much of it on exercise. On average, people only spend 6.6% of their free time exercising. For hunter-gatherers, much of their work and chore time is spent exercising.
Another shortfall is in play. While modern Americans like games and spend time playing them, it is not very much time compared to what hunter-gatherers spend on play. Not only do they dedicate more of their leisure time to play, but their work might also be considered play.
Another potential reason why people experience tiredness is chronic pain conditions. Approximately 25% of American adults experience chronic pain. Often, people have multiple sources of chronic pain, also known as chronic overlapping pain conditions (COPC). TMJ is one of these pain conditions, but it links to numerous other chronic pains, such as migraine, chronic lower back pain, irritable bowel syndrome (IBS), vulvodynia, fibromyalgia, and more.
Chronic pain is exhausting, plus it can interfere with sleep.
We can also look to snoring and sleep apnea for their contribution to our exhaustion. Surveys of modern people only record how much time we think we spend asleep, but in actuality, we spend a lot less time sleeping, especially if you have sleep apnea, which causes you to wake up repeatedly through the night.
Sleep apnea is probably virtually unknown during these pre-industrial peoples. Obesity is one of the primary risk factors for obstructive sleep apnea. Since essentially none of them is obese, sleep apnea is likely rare. Perhaps 25% of American men and 10% of American women have sleep apnea.