Humans Were Engineered to Move

Can we be “healthy” if we’re not active?

Human evolution is deeply intertwined with movement. Throughout evolution, our bodies were engineered and optimized for movement. Our ancestors roamed vast landscapes, gathering food, hunting, and surviving through constant physical activity. In stark contrast, modern sedentary behavior, facilitated by technological advancements and conveniences, has made physical inactivity more common. Unfortunately, this shift away from movement has profound implications for our health, particularly when we examine the physiological processes that rely on regular physical activity.

The science surrounding this evolutionary mismatch is alarming. This paper, recently published by Inigo San-Millan, should worry anyone who thinks humans can be healthy despite being sedentary. Because the human body was engineered to move, many complex physiological processes have been designed to function normally when we are active. Being sedentary is the intervention brought by modernity. When we are sedentary, the processes that control how we process and utilize energy dramatically differ from when we are sedentary.

In the study I referenced, sedentary individuals exhibit significantly worse mitochondrial function and metabolic health than active individuals. For example, sedentary people experience a 36% decrease in mitochondrial respiration at rest, a 35% reduction in fat oxidation, and a 37% decline in pyruvate oxidation. These impairments contribute to lower energy production and increased risk of metabolic diseases. On the other hand, active individuals maintain better fat metabolism and mitochondrial efficiency, underscoring the critical benefits of regular physical activity for metabolic health. Again… our bodies were engineered to move. That’s their baseline. That’s their expectation. Being sedentary has brought forth numerous evolutionary mismatches that have resulted in many metabolic diseases we find ourselves contending with.

The Body at Rest vs. the Body in Motion

The body’s processes work in harmony when active but degrade in a sedentary state. Let’s examine how movement impacts critical bodily systems:

1. Metabolic Health

• In Motion: Moderate physical activity stimulates glucose uptake by muscles without relying solely on insulin. When we walk briskly or engage in similar moderate activities, our muscle cells consume glucose for energy, improving insulin sensitivity and minimizing the onset of metabolic diseases such as Type 2 diabetes. Additionally, exercise activates enzymes that metabolize fats, enhancing fat oxidation—a sign of properly functioning mitochondria.
• Sedentary: When we are sedentary, glucose uptake and fat oxidation slow down significantly. We lose the ability to oxidize fat for energy as we become more insulin-resistant. Insulin becomes less effective, leading to insulin resistance, a precursor to diabetes and metabolic syndrome. Blood sugar levels can rise after meals, and triglyceride levels as a consequence of altered fat metabolism and excess glucose and energy stores.

2. Cardiovascular Function

• In Motion: When walking, jogging, or performing moderate-intensity activity, our heart pumps blood more efficiently. Regular physical activity strengthens the heart muscle, improves blood vessel elasticity, and increases blood flow. This process reduces blood pressure and decreases the risk of harmful plaque buildup.
• Sedentary: Prolonged sitting or inactivity contributes to the stiffening of arteries, higher blood pressure, higher chronic inflammation, and the development of atherosclerosis. Poor blood circulation increases the risk of heart disease and stroke. In a sedentary state, the heart’s efficiency drops, leading to more significant fatigue and susceptibility to cardiovascular problems over time.

3. Muscle and Skeletal Health

• In Motion: Regular activity like walking enhances muscle endurance and strength. It promotes the formation of bone tissue, improving bone density and reducing the risk of osteoporosis. Muscle contraction during activity also releases myokines, which have anti-inflammatory effects and improve overall health.
• Sedentary: Lack of movement leads to muscle atrophy, where fibers shrink due to disuse. Bone density decreases, making bones more brittle and prone to fractures. Inflammatory markers rise, and conditions like sarcopenia (age-related muscle loss) are exacerbated.

4. Hormonal Regulation and Fat Storage

• In Motion: Exercise regulates hormones like leptin and adiponectin, which help control appetite and maintain a healthy balance of fat storage. Physical activity also triggers the release of growth hormones, which are important for tissue repair, muscle growth, and overall recovery.
• Sedentary: Prolonged inactivity disrupts hormonal regulation. Leptin resistance can occur, leading to overeating and excess fat storage, especially visceral fat—the fat stored around internal organs. This type of fat is associated with higher risks of diabetes, cardiovascular disease, and other metabolic disorders.

5. Cognitive and Mental Health

• In Motion: Physical activity increases blood flow to the brain, improving cognitive function, memory, and mood. Regular exercise stimulates the production of neurotransmitters like serotonin and dopamine, which are essential for reducing stress, anxiety, and depression. The brain thrives on movement, which supports neuroplasticity—the brain’s ability to adapt and grow.
• Sedentary: Sedentary lifestyles have been linked to cognitive decline and increased risks of dementia. Lack of activity correlates with higher rates of depression and anxiety due to the absence of mood-boosting chemicals that physical activity naturally stimulates.

The Case for Moderate Physical Activity

Moderate physical activity, such as brisk walking, is one of the simplest and most effective ways to maintain health. Brisk walking for 30 minutes a day can lead to significant improvements in all the areas mentioned above:

• Improved glucose regulation and fat metabolism, reducing the risk of Type 2 diabetes.
• Better cardiovascular function, including lower blood pressure and reduced cholesterol.
• Enhanced muscle strength and bone density, protecting against osteoporosis and sarcopenia.
• Better hormonal balance, reducing the likelihood of obesity and metabolic syndrome.
• Improved cognitive health, reducing risks of dementia, and enhancing mood.

The Long-Term Health Implications

The health implications of a sedentary lifestyle are stark. Sedentary behavior increases the risks of many chronic diseases, including heart disease, Type 2 diabetes, obesity, and certain cancers. It can accelerate aging, reduce lifespan, and severely limit the quality of life as individuals age. Conversely, regular movement, even as simple as a daily walk, can dramatically reduce these risks and support healthier aging.

Bridging the Gap: Moving Toward a More Active Life

In a world filled with technological convenience, it’s easy to be lured into a sedentary lifestyle. The key to better health isn’t necessarily in intense exercise regimens but consistent, moderate movement. If we can reintroduce daily activities like walking, we tap into our evolutionary design and optimize the physiological processes that keep us healthy.

Our bodies are engineered to move, and movement, even at moderate levels, should be a non-negotiable part of our everyday lives. The consequences of not moving are clear—chronic disease, declining mental health, and reduced physical capacity. However, simply getting up and walking daily can be transformative, enabling us to live longer, healthier, and more fulfilling lives.

Reclaim your full biological potential. Just move, move more, more often, occasionally with ferocious intent.