How a Theory of Evolution Can Help Explain Injuries and Inform Training

The following is an expanded article that contains both new ideas as well as fragments originally appearing in a prior article by Jesse McMeekin. This is why you may hear me reference a concept, perspective, model, or quote using the words, “I,” “me,” “my,” and similar terminology.

Those of you familiar with my model have no doubt heard me theorize that the single biggest driving factor in the sports injury epidemic is one and the same as that for society’s declining health—both ultimately symptomatic of modernity. In other words, the modern maladaptive environment turns us into something like a slow burn version of fish outside the tank. Only, instead of flopping around for a bit before it’s curtains, we undergo a slower, more drawn-out process by which degeneration slowly but surely takes root and manifests in various ways.

This is the core theoretical model I explored in my book—Adaptive Nutrition—before pivoting into the applied side. Specifically, how one can improve their health and performance through creating a more nourishing, generative lifestyle within the context of the modern world. The end goal being to not just survive—but to thrive.

This sets the stage for what’s known as the Jacksonian Dissolution—named after its creator, John Hughlings Jackson, and introduced to us by Dr. Pat Davidson. The idea is more fully elucidated in a distilled form in The Polyvagal Theory. This concept isn’t the whole show, but is a fundamental component of my structure-function-energetics model of health and performance.

In essence, the core concept states that as a system or organism evolves, it becomes at once more flexible, more complex, and—due to this complexity—more fragile. When exposed to stress, the usually complex and flexible system devolves to simpler states, sacrificing complexity for survival.
The core concept states that as a system or organism evolves, it becomes at once more flexible, more complex, and—due to this complexity—more fragile, says @rewirehp. Share on X

How Does This Show Up In Health and Performance?

At some level, this is less complex than it sounds and you’ve no doubt seen it in action. A great example is that under fatigue, movement gets sloppier. There are, however, more telltale signs and interplay with other biological systems working under the athlete’s hood, and various ways in which this can then manifest. By better understanding these concepts, you’ll be able to have a more organized and structured framework from which to assess and address stress with your athletes.

In application, what the theory is really describing is how complex systems, such as biological organisms, respond to stress and adversity. In the context of training or sport performance, it suggests that as a system (e.g., the body on the whole, a motor output, or a specific physiological pathway) becomes more complex and flexible, it also becomes more fragile and prone to break down under stress.

We as coaches should do what we can in order to understand environmental stress that cumulatively piles on as allostatic overload, says @rewirehp. Share on X
If you don’t read anything beyond this point, here’s the key takeaway: we as coaches should do what we can in order to understand environmental stress that cumulatively piles on as allostatic overload. From here, we pull whatever levers we can from the perspectives of program design and load management while also educating athletes on ideal lifestyle inputs that can help them minimize the stress of playing, training, traveling, life, and more.

Stress-Reduced Regression in Action

Stress-reduced regression refers to the idea that—as stress accumulates—the system devolves to simpler, more primitive states, sacrificing complexity for survival. This is evident in examples such as:

• Energy Systems: As the body’s three primary energy systems (alactic, lactic, and aerobic) evolved, they became increasingly complex—the electron transport chain and the Krebs cycle—and increasingly flexible in their use of substrates as fuel, and increasingly susceptible to being derailed by environmental factors.

If you subject a resting body to sufficient stress, it will shift its energy production from predominantly aerobic to more anaerobic (lactic). And if the stress is of sufficient intensity, the body shifts all the way back down to the prehistoric alactic system. Surely one can picture the energy systems of an athlete subjected to acute (or chronic) stress downgrading, limiting performance, and potentially opening them up to injury.

• Planes of Motion and Movement Patterns: When it comes to planes of motion, the sagittal plane is the foundation for the frontal plane. The transverse plane is built from and upon both the sagittal and frontal planes. With limited stress, we move freely through all three. But we regress as stress accumulates; normally smooth, fluid gait patterns becoming the staggering waddle of a drunk (or someone after leg day) as we lose control of all but the simplest expressions of movement—flexion and extension.

In “Rethinking the Big Patterns,” Dr. Pat Davidson cites how devolutions in human posture and movement closely mimic our closest ape ancestors (for helpful background context). A quite literal trip down the evolutionary ladder. In essence, as stress accumulates, the body may regress from complex, fluid movements to simpler, more primitive patterns. This is exemplified in the example of a person’s static posture or gait pattern changing from smooth and aligned to projected forward or stumbling under fatigue.

• Henneman’s Size Principle: This states that motor units are recruited in order, from smallest to largest. The upshot is that the first muscle fibers called upon are the low-force, high-endurance, slow-twitch fibers (type I). The body’s-high force, low-endurance fibers (type II) aren’t recruited unless either increased force or power is required (heavy weight or fast movement)—or as fatigue of the type I fibers sets in. Among the practical benefits of the body’s strategy is the ability to limit fatigue by relying on mitochondria-rich type I muscle fibers.

Examined through the lens of Jacksonian Dissolution, we see a tendency for stress to break down yet another system with concurrent costs and benefits shifting in order to complete a given task. Heavy weight (high stress) reduces us to a more basic, more durable, but less efficient state.

• Motor Control: The higher the level of systemic stress, the greater the loss of motor control abilities. This can happen in both an acute setting (e.g., an NBA player changing time zones, disturbing sleep rhythms) as well as in a chronic capacity (e.g., energetic mismatches from high demands of sport and life relative to energetic intake from diet and environment). We’ve all experienced moments where our nervous system is shot and unable to manage the intricacies of more complex, coordinated, demanding movement tasks under the stress of fatigue.

We’ve all experienced moments where our nervous system is shot and unable to manage the intricacies of more complex, coordinated, demanding movement tasks under the stress of fatigue, says @rewirehp. Share on X

• Cognitive Abilities and Emotional Regulation: Yes, J.D. can also manifest itself in both how we take in—and show up in—the world. Neuroscientist David Eagleman likes to say “our reality depends on what our biology is up to.” That’s a pretty solid way to describe this phenomenon. This is also a particularly helpful area as it can tip off trainers and health practitioners to potential chronic or acute disruptions in physiology that may first be more obvious in how someone presents. Similarly, cognitive functions can exhibit Jacksonian Dissolution. Under stress or fatigue, individuals may revert to more primitive, automatic responses, such as swearing out of frustration or emotional outbursts, as their normally refined language processing abilities are overwhelmed. The same can be said of information gathering abilities.

The Stress Response: Implications for Training, Load Management, and Program Design

Stress management is the first implication to keep in mind. Recognize that training is a stress-management process. Aim to apply stress in a targeted, controlled manner to drive desired adaptations. McMeekin points out in his initial article on this subject that it can also be helpful to look at individual training sessions as a singular dissolving event. You’re probably looking at wanting to save movement tasks with greater energetic requirements prior to plugging in simpler, more guttural things—such as sled drags—that sap energy and are fairly safe to accomplish in a more fatigued state.

As far as stress on the whole, Coach Kyle Dobbs notes that effective training essentially comes down to stress management. That’s a pretty succinct summary of any intelligent training model, and Jacksonian Dissolution is simply a way of understanding what happens as we apply stress to various bodily systems. The aim of applying stress is to temporarily degrade or dissolve a system; following training you are slower, weaker, and less coordinated than you were beforehand. But stress drives change, and the temporary degradation in abilities ultimately leads to lasting improvement.

Having a foundational understanding of systems biology and the bioregulatory processes that govern health and performance—including the interplay of these systems—is key.

• Consider the interplay between various bodily systems when designing training programs.
• Avoid overwhelming individual systems, as this can lead to devolution and reduced effectiveness.

In addition to acknowledging the performance physiology that supports athletic endeavors, coaches must understand the stress response. By better understanding what’s going on under the hood, we can make more informed coaching and lifestyle decisions. Ultimately, the stress response and all its requisite components—glucagon, epinephrine (adrenaline), norepinephrine, cortisol, growth hormone, etc.—are some of the human body’s most adaptive and beneficial mechanisms. Stress—in the right doses and with adequate recovery—is tremendously good for us! And Jacksonian Dissolution can serve as a window into our stress response.

Stress—in the right doses and with adequate recovery—is tremendously good for us! And Jacksonian Dissolution can serve as a window into our stress response, says @rewirehp. Share on X

There are also implications for basic concepts we’re all familiar with as coaches, like progressive overload. Gradually increase stress (load) to allow for adaptation and avoid sudden, catastrophic failures. Meet athletes where they’re at, in other words.

Additionally, generalized stress isn‘t enough for an efficient training stimulus. Stress should be a sniper rifle, not a shotgun, and a workout that leaves you panting and nauseated may or may not be driving the change you’re looking for. Jacksonian Dissolution looks at individual systems, not entire organisms. While there’s sure to be some overlap, say, between muscular fatigue, energy system recruitment, and elements of how we present in life (e.g., language use and processing), it’s important not to seek stress for its own sake. Wham, bam, beat-em-up training could have its place, but seeking difficulty for difficulty’s sake is not the move.

Recovery is another quality with implications we can take from Jacksonian Dissolution. Ensure adequate recovery time as well as positive environmental inputs in the form of diet, sleep, light diet, and beyond in order to allow for rebuilding and refinement of complex (and other) systems.

Applied: 5 Interventions Coaches Can Use to Manage Allostatic Load

1. Educate clients on the importance of sleep

This should more or less go without saying, but educating athletes so they can dial in their sleep hygiene may be the most effective stress management lever we can pull. Research shows that injury potential increases by as much as 70% following disruptions in sleep quality.

Rather than obsessing over wearable metrics, the focus should be on getting clients more in tune with how they feel and teaching them to listen to their bodies by checking in with themselves more effectively. Aiming for 8.5 hours of sleep (but at least over 7) is good practice for most. Exposure to natural light during the day, morning, and evening likely helps tune our circadian biology, as well. Reduction strategies for blue light can be effective here, too. A nutrition intervention specific to sleep would be glucose in the evening before bed (e.g., milk and honey) as insulin opposes stress hormones like cortisol in the system—effectively helping athletes silence the stress response and prime their nervous system before rest and restoration.

2. Be flexible by keeping a regulatory or adaptive program design model to meet athletes where they’re at physically

Just because something is written down on paper, doesn’t mean we have to do it. Plan A should be flexible if athletes are in an acute or chronically fatigued state. Omegawave’s Windows of Trainability and athlete readiness concepts are useful to keep in mind here.

3. Consider educating athletes on mindfulness installations

Living a more balanced life in general—meditation, mindfulness strategies, time spent doing nothing, time outdoors, and more—are all potential inputs that can improve our responses to stress. Mike Franco—a mental skills coach in the NBA—is a great example who shows how integrating mindfulness into sports can be done successfully.

4. Don’t neglect nutrition

Diet is another one of the giant levers here. Injuries and degradations in performance often occur because of an energetic mismatch between an athlete’s outputs and their environment. In addition to the other inputs like sleep, we should be educating athletes to improve their energetic state through diet so they can “bite off” more of the stress that training, playing, and life have to offer.

The obvious first boxes to check would be mitigating junk food and unwanted ingredients while also ensuring there’s not a big caloric or macro deficiency. I give more targeted recommendations in the book, but in general we want to stay away from diet dogmas that may actually plunge athletes into more of a survival state (e.g., extreme diets like plant-based, low-carb, carnivore, keto, chronic fasting). Instead, the goal should be to select foods that are high in energy yield relative to energy lost from digestive obligations and from managing inflammation. This can simplify the process of how to build one’s base of food substantially.

5. Inspect what you expect; have informed tests you use with athletes if it’s feasible

Paying attention to clients and meeting them where they’re at is the most important measure here. That said, looking at deteriorating output-based metrics can also be incredibly helpful. Whether it’s reflex tests, tap tests, or something more quantitative like CMJs (we use Hawkin Dynamics force plates for this), numbers in the gym may all be useful here.

If one has the ability, use temperature and pulse rate (with disturbances in both over a multi-day period potentially serving as a canary in the coalmine for systemic stress) as a “check engine light” for metabolic stress/state.

There are other useful measurements here, such as integrating quality stress measurement devices, like Omegawave, and well-done HRV.

Paying attention to clients and meeting them where they’re at is the most important measure here. That said, looking at deteriorating output-based metrics can also be incredibly helpful, says @rewirehp. Share on X

Parting Shots

If we accept that training is at some level stress management, Jacksonian Dissolution is at once a measure of the stress being applied, a way to understand the effect(s) of that stress upon a given system, and a framework for how to apply that stress in a safe, effective manner.

As a measure of stress: I’ll be as clear as I can be—and will close with the same thought for good measure—effective training should be terrifyingly hard at points. I want people reduced to their baser selves, far removed from the niceties of our sedentary society. And it’s a rare person who will go there voluntarily, who signs up for what at times amounts to near-torture. In these moments, part of my role is to ensure that things are as hard as they need to be, and Jacksonian Dissolution offers a fairly robust way to examine your response to stress. Your posture, body language, the way you breathe, word choice, movement quality, the length of your sentences… all of it is a source of feedback, and I need to see at least some of it deteriorate.

Your posture, body language, the way you breathe, word choice, movement quality, the length of your sentences… all of it is a source of feedback, and I need to see at least some of it deteriorate, says @rewirehp. Share on X

Training can’t stay pretty all the time.

Having hopefully argued convincingly in favor of applying real, meaningful levels of stress via training, it is every bit as important that we consider both the allostatic load—total stress—an individual is under as well as their strategies to manage that stress. Are their nutritional, sleep, and leisure activities conducive to high or low applications of stress? Do they have a social system they can lean on for support, or one that requires support from them at the moment? Don’t shy away from stress, but be aware that we are almost literally playing with fire; we want to toast the marshmallow rather than set it on fire, so to speak.

As a way of understanding the effects of stress: Perhaps the simplest way of understanding a system under stress is via the particular model of Jacksonian Dissolution. Under sufficient stress, a system will revert to simpler, more primitive alternatives.

As a guide for stress application: In designing a training program, coaches should consider what kind of stress is best suited to the person, the movement, and the degree of fatigue they’re experiencing (early vs. late in the workout, for example). Our big, sagittal movements lend themselves nicely to heavy loads and high fatigue. I can deadlift, squat, press, and row through enormous fatigue.

In designing a training program, coaches should consider what kind of stress is best suited to the person, the movement, and the degree of fatigue they’re experiencing, says @rewirehp. Share on X

But that becomes a different story for more complex movement tasks. As movements become less stable or more complex, stress needs to be applied in a different way. The nervous system already perceives the body’s position as an elevated source of threat, and heaping on too much additional stress can end badly. In these cases, additional stress—in the form of too much load, too little rest, and the like—can actually detract from the intended training effect by allocating resources to the wrong stressor. Dr. Pat Davidson talks about the need for additional “ground” (external support and neurological references) as an ideal starting place for newcomers as well as those in fatigued states (e.g., an NBA player in-season).

When we introduce speed and power into the mix, things get even dicier as fatigue sets in. Box jumps are a terrific, low-intensity way to develop explosive power, but done as a “finisher” or as part of a circuit—particularly with an athlete jumping back off of the box—the injury risk they pose may not be worth the reward. In addition to the potential for injury, the effect of the stress may again be misplaced. Stress is specific; if the intent is to develop power and explosiveness, the fatigue the body is under will limit the amount of power being expressed and, therefore, developed.

How you fit the puzzle pieces together will vary tremendously—we haven’t even considered the athlete/client, their goals, ability level, and the like—but certain overriding principles can and should guide our choices regardless of who we’re working with. Stress drives adaptation, but stress is system-specific. A hard workout may not be an effective one.

Ultimately, by acknowledging Jacksonian Dissolution in the training environment, coaches and trainers can better understand the dynamic interactions between bodily systems and design more effective, adaptive training programs.

I suppose I’ll leave you with this. We need stress. It shapes us. Both in sport and fitness, as well as growing in life on the whole. And stress is ugly, messy, frightening, and primitive. Stress is savage, and at times you need to meet it head on. Think about how and when you apply stress, but when it’s time to get to work, be a savage.

Jesse McMeekin is a trainer, educator and coach. You can find him at his website www.adapt-performance.com.

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