Mind and Muscle: What Controls Your Effort?

High-level performers and people who cope with extreme situations are able to move closer to that maximal threshold, extracting a higher degree of their potential at will. While the debate continues as to whether human limitations are voluntarily or involuntarily regulated and mentally or physically determined, the evolution of exercise science has taken us away from the idea that humans are machines and that performances are the mindless application of particular physical skills and abilities.

Mind and Muscle: What Controls Your Efforts?

“…himself meanwhile unparticipating in the passions, and actuated only by that pleasurable excitement, which had resulted from the energetic fervour of his own spirit in so vividly exhibiting what it had so accurately and profoundly contemplated.” – Samuel Taylor Coleridge, Biographia Literaria, Ch. XV (discussing Shakespeare’s Venus and Adonis)

There is a persistent falsehood surrounding physical prowess. It is the belief that physical virtuosity is somehow opposite the arts or academic achievement, that brains and brawn are at polar ends of some imagined spectrum. Where that dichotomy comes from and what it says about society is far and away beyond the scope of our interest here. As we have recently written about different theories in the mental aspects of sports performance, coaching, and mental toughness, however, that misconception has seemed more stark, as the growing body of research into the mental aspects of physical performance tends to highlight the same characteristics that lead to success in other areas as well.

In the above quote, Samuel Taylor Coleridge is writing about the lessons he learned from reading Shakespeare and highlights the quality of “aloofness” in which the Bard seems to be engrossed in creating while separated from his own feelings on the subject matter. Coleridge recognized that the artist has the ability to stand in his own way, subjecting his talent and creativity to the control of his emotions or feelings. There is a parallel here between what Coleridge identified as artistic genius and feats of astounding physical accomplishments.

Physical feats that push the boundary of human ability require that a person access an incredibly high percentage of his or her ultimate, absolute, beyond-this-is-death ability. We each have an unknown threshold for physical exertion, including but not limited to our ability to produce force, our endurance, or durability. Beyond that threshold is physical breakdown, leading almost certainly to serious injury and, at the extreme, a threat to life. Yet, rarely do human beings actually exercise themselves to death.[1] Instead, we constantly operate at a level below our maximum ability.

From Machine to Mind-Body

If our bodies were just a collection of inputs and outputs, then performance would be entirely predictable across populations, once you account for environmental factors. This view of physical performance—the “body as a machine”—comes from exercise physiology pioneer A.V. Hill who investigated human performance with an insatiable curiosity.[2] Hill would jump ahead in his conclusions, acknowledging the limitations of the investigations of his time but operating under the belief that if we could understand the detailed ins and outs of the complex human-machine, we could also predict and replicate its capabilities.

“One of the fundamental characteristics of striated muscle, and the one involving the greatest difficulty in investigation, is the great rapidity with which changes take place in it. There is no doubt that ultimately the muscle is a chemical mechanism . . . . If we were aware of all the chemical events, we should know all that was necessary about the machine which we are studying. Unfortunately, the investigation of chemical events is a slow and laborious process.” (David R. Bassett, JR. “Scientific Contributions of A.V. Hill,” J. Appl. Physiol 93: 1567-1582, quoting Hill’s Nobel Prize lecture.)

Two years ago, Nike put the human-as-machine theory to the test in an attempt to deliver a sub-2-hour marathon time. The attempt grew out of a thought experiment by researchers concerning the physical determinants of running performance—inputs and outputs. The inputs, they wrote, are “Vo2max, lactate threshold, and running economy.” These had been used to model and predict marathon performance previously. If you could find a runner with the right combination of extremely high values of Vo2max, lactate threshold, and outstanding running economy, then if you could also control for environmental factors. Then, if you could get that runner to show up for race day in peak performance shape. That runner should be able to break the 2-hour marathon barrier.

Eluid Kipchoge seemed to have the right combination of traits to break the 2-hour marathon. And he came close in the Nike event, running a marathon distance in 2 hours and 25 seconds with the aid of pacers, on a seemingly optimal track, and with as much support a Nike could muster for the attempt. Watching the National Geographic documentary “Breaking2” of the event, it’s hard to claim that Kipchoge fell off the pre-determined pace for any non-biological reasons. It just wasn’t there, which seems to give weight to his performance as one of inputs and outputs. For whatever reason, on that day, he was physically incapable of running the marathon in under two hours.

Then again, earlier this year, Kipchoge did break two hours, running an amazing 45 seconds faster than his Nike attempt in another experimental run, the “Ineos 1:59 Challenge,” finishing in 1:59:40. The lingering question is whether Kipchoge was better prepared or in better form for this second attempt. Perhaps, however, the experience of his first attempt gave him a mental edge, or something else in his motivation or approach to the race changed that had less to do with his physical abilities. Nike scientists had measured his running ability, and he could have run under 2 hours the first time. But something changed in this second attempt that allowed him to tap into even more of his physical capabilities. We can only speculate, but there is the possibility that something deep in his subconscious held him back in the Nike attempt.

Central Governor Theory

Whether we want to or not, humans always seem to be holding something in reserve. It is rare that an athlete will push him or herself to the point of complete exhaustion, even when Olympic gold is on the line. The theory is that a complex mechanism in our brains acts as a “central governor,” limiting our ability to push ourselves to our true physical limits. Under this theory, even the greatest motivation in sports cannot override the safety mechanisms of the brain and allow you to race, lift, or otherwise exert yourself to death.

We do observe this kind of exertion to exhaustion in certain animals under the right circumstances. Prey animals in actual life-or-death situations can be stalked and hunted until they collapse, near death from the effort. Early human hunters with our large capacity to sweat and remove heat from our bodies and, therefore, sustain low-intensity chases for a very long time, would use this tactic to run prey into the ground. Similarly, trained horses can be goaded into running until their hearts or bodies give out. For the animals, continued exertion truly is life or death. But in a performance or training setting, our brains seem always to hold something back.

Tim Noakes, who popularized the central governor theory, believes that the central governor is neither reactive nor voluntary. In his theory, humans evolved as predators with an ability to conserve energy, rather than to expend it. “A key feature of this control is that it acts ‘in anticipation’ specifically to insure that catastrophic biological failure does not occur.” (Timothy David Noakes, “The Limits of Human Endurance” Adv Exp Med Biol.618:255-76 (2007).) We evolved to run in the heat for long distances, to throw accurately, and to hit with power and to persevere when chasing down prey. But that perseverance of a goal could be potentially harmful. So, we developed an internal regulation to help maintain a reserve: “Two crucial features of the physiology programmed into our genes by our evolutionary past are likely to be (i) the capacity to pace ourselves during exercise so that (ii) we complete each exercise bout with functional reserve and without the development of total physical exhaustion.” Yet, as Noakes argued at the time, exercise physiologists, tending to follow A.V. Hill’s “human as a machine” lead, had been attempting to understand human exertion with the assumption that humans reach a state of complete exhaustion during exercise. (Id.)

If Noakes is correct and the involuntary central governor theory applies to strength training as well as endurance, there may be a defeatist conclusion with his theories. In essence, your one-rep-max can never truly be your One Rep Max because you cannot access your true potential, even with perfect form and the right motivation.

Perhaps endurance athletes are more willing to accept these theories, however, because it’s hard to imagine a runner in the last one hundred meters of a moderate distance race in the Olympic finals, two steps behind first place, lacks the motivation to squeeze just a fraction of a percentage more out of her legs to pull ahead and win.

Lifters know, however, that mindset can be extremely important in a PR attempt. Just watch the lifters on deck for the third attempt of a deadlift in a big meet. You will see slaps, ammonia capsules, death metal blasting on headphones, and people who look like they’ve channeled Zuul before stepping onto the platform. Perhaps we cannot completely override the central governor, but we seem to be able to turn it down a little bit with our pre-lift antics.

Psychobiological Model

A theory that has grown out of the central governor is one that combines psychology with exercise physiology, arguing that while your brain regulates your effort, your conscious mind has the controls to the dimmer switch. UK exercise physiologist Samuele Marcora doesn’t quite argue that slowing down or regulating your effort is a choice, but rather than it is controlled your perception of effort, which is, in turn, influenced by numerous conscious and subconscious factors.

Marcora starts with the prevailing view that fatigue comes in two forms: peripheral fatigue and central fatigue. Peripheral fatigue describes problems in the motor pathway originating at the junction between a motor neuron and a muscle fiber or farther down the chain of events that produce a voluntary muscular contraction, including depleted energy stores, muscle impairment due to damage to the fibers, or an impaired muscular response due to accumulated byproducts or exercise-induced muscle damage. Central fatigue describes motor impairment that originates in the CNS. Your CNS integrates input from various sources of the body, limiting muscle contraction and force production when that input suggests that doing so would be beneficial to your continued survival.

Central fatigue, however, may arise from non-physical sources like mental fatigue, self-belief, and superstition. In one compelling study, Maracora had a group of elite rugby players cycle to exhaustion, meaning they were given a pace at about 80% of their maximum abilities and told to cycle until they couldn’t pedal anymore. Their average power output during the exhaustion test was 242 watts, which they sustained for an average of ten minutes. When the players stopped due to “exhaustion,” they were immediately asked to see how hard and fast they could pedal for five seconds. Logically, if the player was truly incapable of pedaling another stoke at 242n watts, then the five-second test should have produced a lower output. Instead, the players averaged 731 watts during the five-second interval. Either the players had not been adequately motivated to cycle to exhaustion in the first interval, or they had falsely believed themselves exhausted. Either way, their reported effort at the end of the first test was false; they were not exhausted. Maracora believes this shows that there are other factors that affect your perception of effort, and that perception is the true control that regulates your effort.

When you are getting hyped up for the new plate-PR deadlift, you are using various mental techniques that take your focus away from the weight on the bar and the perception that the bar is too heavy to lift. You are distracting yourself so that the perception of effort is less, and your brain is less likely to interfere and down-regulate your force production capabilities in order to keep you safe.

Taking Yourself Out of the Picture

Somewhat ironically, the theories that have integrated the mental approach to physical performance seem to point backward. The best way to perform to your greatest potential is to turn yourself into a machine, as much as possible. If you can operate without the regulation of your perception or your survival instincts, you are likely to access more of your potential. There is no doubt that someone like Kipchoge is, more-or-less, a running machine. He is able to perform at a consistently high level, which speaks not just to his phenomenal physiology but his willingness to put himself right on the edge of maximal performance for extended periods of time. As lifters, when we get hyped up or follow our weird superstitions, listen to our very particular lifting songs, and try to go a little bit insane before a lift, we are essentially taking ourselves out of the lift. Moved to action, as Coleridge wrote, by “the energetic fervour of [our] own spirit in so vividly exhibiting what it had so accurately and profoundly contemplated.” We preempt perceived effort rather than tentatively approaching the bar, feeling its weight, and judging in the moment whether we have the strength to move it. That perception is anathema to heavy lifting. Great physicality requires a mental approach that mirrors performances in other areas. That mental approach is something you can cultivate no matter your innate abilities.

[NOTES]

[1] It is certainly possible to hurt yourself and even induce life-threatening circumstances through exercise. Chronic overtraining leading to serious health complications are a relatively common cause of exercise-induced exhaustion. As are heat-related illnesses and loss of fluid balance. We have written about some of these topics before:

Injury due purely to central or peripheral fatigue, however, is relatively rare. If it weren’t, many more athletes would drop dead from exertion in events like the Olympics, where there is an overriding motivate to push one’s body to its absolute limits.

[2] A.V. Hill: “You will ask—I have often asked—what happens to the body in training? I am sorry, I do not know. Perhaps the blood supply to the active muscles becomes better, the capillaries responding more rapidly to the needs of the muscles; perhaps more alkali is deposited in the fibres to neutralise the acid formed by exertion. More glycogen seems to be laid down in them as a store of energy, and certainly, they and the nervous system which governs them learn in training to work more economically. Perhaps by training the recovery process is quickened. Maybe the actual mechanical strength of the muscle-fibre and its surrounding membrane (sarcolemma) is increased by training so that it can stand, without injury, the strains and stresses of violent effort. All these factors may be at work, but at present we can only point to the importance and interest of the problem, and suggest that someone should investigate it properly.”

Mind and Muscle: What Controls Your Effort?