Have you ever wondered, if running was bad for your knees, wouldn’t ultramarathoners be paralysed? But they are not. That is the main question that gave me a strong passion about reading this book that was recommended by Hakim a friend who is also an avid runner.
I started wanting to improve my running even though I didn’t love running because it provided a consistency to my morning and a mood enhancer from the achievement. The book helped provided a renewed motivation and comfort that we are built to run.
Below is my conclusion about running then the next section we dive into the summary of the book.
Quick Learning – I believe we should run
Key Scientific Considerations
1. Cartilage and Synovial Fluid (“liquid between knees”)
- Cartilage doesn’t have its own blood supply—it relies on movement and joint loading to get nutrients through synovial fluid.
- Moderate, well-controlled running has been shown to improve joint health, not degrade it.
- A 2017 meta-analysis in Journal of Orthopaedic & Sports Physical Therapy showed that recreational runners had lower rates of knee osteoarthritis than sedentary individuals and competitive runners.
2. Bone Is Alive — and Responds to Load (Wolff’s Law)
- Bones are not just hard, inert material. They’re living tissue that constantly remodels itself in response to mechanical stress.
- According to Wolff’s Law, bone adapts to the loads it’s placed under. When you run, the impact stimulates your bones to increase density and strength over time.2. Injury Risk Factors
- Professionals often push into overtraining zones, hence higher injury rates—not because running itself is bad.
- Most chronic running injuries stem from overuse, poor mechanics, lack of cross-training, and inadequate rest, not from age alone.
3. Running form
Getting the right running form prevents injury and strengthen instead. See below for the form recommended by the book.
4. Injury Risk Factors
- Professionals often push into overtraining zones, hence higher injury rates—not because running itself is bad.
- Most chronic running injuries stem from overuse, poor mechanics, lack of cross-training, and inadequate rest, not from age alone.
This process is especially protective as you age, helping delay or prevent:
- Osteopenia and osteoporosis (age-related bone loss)
- Hip fractures and falls, especially common after age 60+
🤔 But Isn’t Running a “Low Strain” Activity Compared to Weightlifting?
Yes and no:
- Running is considered low strain per repetition but high repetition.
- Each step during a run exerts about 2–3x your bodyweight on the legs.
- Multiplied over thousands of steps, this becomes significant enough to stimulate bone growth, especially in weight-bearing areas (hips, spine, legs).
- Weightlifting or jumping sports apply higher acute loads with fewer reps.
- These are more potent in triggering bone density increases quickly—but also come with higher injury risk if done improperly.
So:
- Running helps maintain and slightly increase bone density, especially if started early and continued consistently.
- Heavy lifting, plyometrics, and sprinting are even more effective for bone, but may not be suitable or safe without proper form and progression.
Here I will summarise the learning from the book:
Born to Run by Christopher McDougall delves into the evolutionary and cultural background of humans as natural runners. Here’s a breakdown based on your requested sections:
1. Anatomy Proof that Humans Are Born to Run
McDougall explores evolutionary biology to argue that humans are physically built for endurance running. He references specific anatomical features that support this idea, including:
- Ligaments and Tendons: Humans have a large Achilles tendon, which stores and releases energy with each step, making running more efficient.
- Nuchal Ligament: Unlike most animals, humans possess a nuchal ligament in the neck that stabilizes the head while running, a feature found primarily in animals that run long distances.
- Sweat Glands: Our bodies are equipped with millions of sweat glands, enabling thermoregulation through sweating, unlike animals that pant to cool down. This allows humans to sustain physical exertion for extended periods without overheating.
- Arched Feet and Short Toes: Human feet have arches that act as shock absorbers, while shorter toes reduce the strain during running. McDougall contrasts this with animals built primarily for speed, which typically have different foot structures.
- Gluteus Maximus and Large Buttocks: The human gluteus maximus muscle is crucial in stabilizing the body during running, providing forward propulsion and maintaining balance.
McDougall supports these ideas with references to studies by Dr. Daniel Lieberman and Dr. Dennis Bramble, evolutionary biologists who researched human anatomy and endurance running in their “Endurance Running Hypothesis.” Their work suggests that traits beneficial for endurance running were likely advantageous for early humans, helping them hunt and survive.
2. Response to “Is Running Bad for Our Knees?”
The book argues that humans, when running with natural form and using minimalist footwear (or going barefoot), are less likely to experience injuries. McDougall examines the example of the Tarahumara, a Mexican Indigenous group known for running ultra-distances into old age with little evidence of knee or joint issues. This evidence counters the idea that running necessarily leads to long-term joint damage.
McDougall suggests that modern running shoes, which alter our natural running gait, are likely contributors to injuries. In fact, studies show that ultra-runners like the Tarahumara, who use minimal footwear and focus on natural form, often maintain healthy joints and muscles well into old age. Thus, the book implies that poor form or improper footwear—not running itself—is often to blame for knee issues, as natural form can help distribute impact forces more effectively.
3. The Right Running Form
The book advocates for a natural, efficient running form focused on the following elements:
- Midfoot Strike: Instead of landing on the heel, McDougall suggests landing on the midfoot or forefoot. This type of landing reduces the impact on knees and lower joints by spreading the impact forces across a larger surface area.
- Cadence and Short Strides: A higher cadence (more steps per minute) with shorter strides helps prevent overstriding, which can lead to joint strain. The ideal cadence is often around 180 steps per minute.
- Upright Posture and Slight Forward Lean: Good posture with a slight forward lean from the ankles, rather than bending at the waist, helps to propel the body forward more efficiently.
- Relaxed Upper Body: Keeping the arms and shoulders relaxed, with elbows at a 90-degree angle, allows for natural arm movement without unnecessary tension.
This form helps runners maximize efficiency while minimizing strain on their joints, mirroring the form of the Tarahumara and other Indigenous groups who run long distances with minimal footwear.
4. The “Superfood” Mentioned in the Book
McDougall introduces chia seeds as a kind of superfood, consumed by the Tarahumara runners to sustain their energy during long runs. He highlights chia seeds as a natural endurance-boosting food, loaded with omega-3 fatty acids, fiber, protein, and antioxidants. The Tarahumara mix chia seeds with water, lime, and sugar to create a drink called “iskiate,” which provides them with long-lasting energy and hydration.
In the book, McDougall explains how chia seeds help stabilize blood sugar and reduce inflammation, making them ideal for sustained endurance activities. This aligns with the Tarahumara’s approach to nutrition, focusing on simple, natural foods that aid performance and recovery.
5. Non-Anatomy Evidence that Humans Are Born to Run
Beyond physical traits, McDougall explores cultural and performance-based evidence to support the argument that humans are naturally equipped for running. Key points include:
- Human Longevity in Running: McDougall points out that humans, unlike most animals, can run well into old age. He references races where older runners compete at nearly the same level as younger athletes, often outlasting them in ultra-marathons. This ability to continue running long distances throughout life is unusual in the animal kingdom, suggesting that endurance running is naturally embedded in human physiology and culture.
- Persistence Hunting: The book highlights persistence hunting, an ancient technique still practiced by some Indigenous groups (such as the San people of the Kalahari), where humans rely on endurance running to track and exhaust prey over long distances. Unlike faster predators that rely on bursts of speed, humans can run for hours to tire out animals, demonstrating an endurance advantage.
- Cultural Traditions and Rites: Running is embedded in the traditions and rituals of several Indigenous groups, like the Tarahumara, where running is both a cultural practice and a means of survival. They view it as a spiritual act, part of their identity, reinforcing that running has long been part of human societies.
- Psychological Resilience: The book emphasizes that humans possess unique psychological traits such as patience, persistence, and adaptability, which are crucial for endurance running. The mental stamina required to run ultra-distances is arguably as important as physical strength, and McDougall suggests this mental resilience evolved alongside our physical running abilities.
These non-anatomical proofs, along with cultural and historical examples, bolster McDougall’s argument that humans are naturally adapted for endurance running, both physically and mentally.
