By Danny Clark

We have been roaming the planet as Homo sapiens for about 200,000 years, but that doesn’t mean key aspects of our physiology haven’t changed dramatically over the course of our history. In fact, modern research speaks of significant shifts in our health and performance over time and these changes are being amplified over more recent generations.

Some may argue that these shifts toward weakness – which include not only our physical strength, but the function of our vital organs and brain – were necessary as our species innovated key technologies. However, the research resolutely indicates that our individual health, wellness, and performance are suffering as a result.

Therefore, the purpose of this article isn’t to vilify the conditions that created the weaknesses, but rather to step back and offer practical insights that can help unify personal human vitality with the modern technological world.

Here are 6 key signs that humans are getting weaker, plus what to do about it.

Decreasing Grip Strength

The headline of this article says it all: “Millennial men are significantly weaker than their fathers.” This bold statement was inspired by a study where researchers compared grip strength measures of men and women across a few generations [1]. It makes sense, as we’ve made the shift out of the fields and into the university lecture hall. But, aside from this being a clear indicator of hand weakness, grip strength has long been used as a proxy for other physical abilities, such as deadlifting, wrestling, and climbing. And, there’s no evidence that indicates people can’t be physically strong and capable, as well as develop themselves intellectually (in fact, being physically fit has shown to improve academic performance in preadolescent children [2]).

What to do about it:

  • Incorporate more climbing movements into your workout, such as hanging, swinging, and getting on top of obstacles.
  • Pick up and carry moderately heavy rocks, logs, or other natural objects for short distances during hikes and nature walks.
  • Climb trees.
  • Learn a martial art and/or take one of our Combatives courses and incorporate some of the drills into your workout routine.

Decreasing Lung Capacity

Your lungs might as well be a muscle, as they are a key indicator of physical performance. And, unsurprisingly, lung volume is a lesser known indicator of health and longevity. Researchers in one particular study found “forced vital capacity” (ie, lung volume) as an all-cause mortality predictor among smoking and non-smoking populations [3]. While few studies compare lung volume trends over our history, it can be safely inferred that the historical demands of a lifestyle that required much more physical labor would have mandated healthy lung volume.

What you can do about it:

  • Learn how to breathe better, with abdominal breathing techniques.
  • Increase your overall work capacity with medium and long duration workouts that stimulate aerobic adaptations. Running and walking are classic movements, but MovNat combos can be designed to emphasize the aerobic system as well.
  • Go on more hikes and other outdoor adventures.
  • Participate in more household chores and lead a generally more active lifestyle.

Decreasing Bone Strength

If our bones had biceps, they’d be looking pretty puny compared to our more formidable days. And, of course they do, since bones serve alongside our muscles as integral parts of our ability to move, stay upright, and resist injury. According to research, we’re losing substantial bone strength – with up to 20% less mass than our ancestors had [4]. This trend toward less bone mass is one of the most conclusive signs that we are becoming weaker as a species. It also sets us up for a host of progressive issues as we age including osteoporosis, increased risk of mortality associated with falling, and more overall dependency.

What you do can about it:

  • Ensure that manipulative skills (ie, lifting, carrying, throwing, catching) are included in your workout routine.
  • Incorporate jumping into your lifestyle and workout routine, ensuring safe technique is used to optimize loading.
  • Be sure to run at varying paces, including an occasional sprint.
  • Use training principles to ensure you get the right dose of stimulation without overtraining or injuring yourself.

Decreasing Mental Capacity

In the field of evolutionary neuroscience, researchers have sought to understand why our modern sedentary lifestyle leads to the degeneration of mental capacity over the course of a lifetime. Their model of “Adaptive Capacity” proposes that our brains have been designed to handle the “cognitively challenging aerobic activity” required for foraging and hunting [5]. In the absence of this movement-based stimulation, our brains decrease function in order to conserve energy. In short, we’re falling short of our mental potential by staying stationary and staring at our screens, as well as putting ourselves at high risk for degenerative diseases as we age.

What you can do about it:

Decreasing Foot Strength

As the foundation of your body, the strength and integrity of your feet really matters. So much so, that the function of everything above depends on them. Some evidence of the decline in our foot strength lies in the booming industry of orthotics, which is a rapidly upward trending market [6]. Further, a study published by Harvard professor Daniel Lieberman et al. compared foot strength and stiffness between men in rural northwestern Mexico and men in urban areas in the US. He found that the men in Mexico who lived minimally shod – more like our ancestors – had less incidences of flat feet and therefore less likelihood to develop common disorders, such as plantar fasciitis, knee osteoarthritis, and stress fractures of the foot [7].

What you can do about it:

  • Spend more time standing and walking barefoot.
  • Rebuild your foot strength naturally by working through MovNat’s ground movement, gait, and balancing progressions.
  • Work on your jump landing technique, building the eccentric strength of your foot.
  • Progressively work toward more minimal shoes, as outlined by our friend Katy Bowman in her book Whole Body Barefoot.

Decreasing Mobility

While most people associate the word “mobility” with flexibility, we at MovNat agree with the Merriam Webster definition of mobility as “the ability or capacity to move.” Therefore, mobility isn’t just about being flexible, but rather having the range of motion, coordination, and fitness to execute real world tasks.

As we’ve shown thus far, weakness is a bigger issue than simply not being strong enough to lift a heavy barbell or rock. In fact, the decrease of all the aforementioned attributes are really a byproduct of the root issue: our lack of movement capacity. As such, the most alarming sign humans are weaker than ever is the loss of our ability to move; our physical capability, i.e. our ability to perform tasks vital to our survival and well being.

The trend toward sedentarism and movement incompetence isn’t new, but rather a progressive one that the young French Navel officer, Georges Hébert, observed in the early 1900s. Hébert served in disaster situations where he witnessed people unable to execute the most vital of tasks – like being able to carry another person to safety, or pull themselves into a raft. On the other hand, he traveled extensively throughout the world and was impressed by the physical development and movement skills of indigenous peoples, writing:

“Their bodies were splendid, flexible, nimble, skillful, enduring, resistant and yet they had no other tutor in gymnastics but their lives in nature.”

What you can do about it:

  • Expand your workout routine to focus on movement competence and work capacity in all the Natural Movement domains delineated here.
movnat movement skills

In closing, there is much we can do to build our strength, resilience, and overall vitality despite the challenges of modern life. And it starts by restoring our ability to move in the many ways we’re meant to…naturally!

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[1] Fain, Elizabeth et. al, “Comparative study of millennial grip and lateral pinch strength with the norms” Journal of Hand Therapy, 29 (2016) 483-488

[2] Hillman, Charles, et al, “The role of aerobic fitness in cortical thickness and mathematics achievement in preadolescent children”  PLOS (2015)

[3] Strachan, David P, “Ventilatory function as a predictor of mortality in lifelong smokers and non-smokers: evidence from large British cohort studies.” Epidemiology Research, 7 (2016)

[4] Timothy M. Ryan and Colin N. Shaw, “Gracility of the modern Homo sapiens skeleton is the result of decreased biomechanical loading” Proceedings of the National Academy of Sciences, 112 (2014) 372-377

[5] Raichlen, David et al, “Adaptive Capacity: An evolutionary-neuroscience model linking exercise, cognition, and brain health” Trends Neuroscience, 40 (2017) 408-421


[7] Lieberman, Daniel et al, “Foot strength and stiffness are related to footwear use in a comparison of minimally vs. conventionally shod populations. Nature, Feb 2018