The topic of the next anatomy of a runner post is muscle. It’s not that we haven’t covered various muscles in previous posts, but their generic characteristics are fascinating as it relates to running and seem to warrant a separate conversation. After all, the brain and muscle are the most malleable of all the anatomical components. In other words, they can be trained.
The purpose of the paper is to illustrate the link between an athlete’s physiology and success in distance running. “The maximal oxygen (O2) uptake, O2 cost of running at sub-maximal speeds (running economy), and blood lactate response to exercise can all be determined using standard physiology laboratory exercise tests and the results used to track changes in ‘fitness’ and to make recommendations for future training,” Jones writes in the introduction.
Once or twice a year Radcliffe was given a physiological assessment that measured height, body mass, body composition (through skinfold thicknesses), haemoglobin concentration ([Hb]), pulmonary function, vertical jump height, a sit-and-reach test, and a multi-stage incremental treadmill test. The resulting data from these tests demonstrate how 15 years of directed training created the ‘complete’ female distance runner and a World champion.
Radcliffe committed herself to many years of hard training and used these yearly assessments to objectively analyze her progress and to inform her training. The data also accurately predicted actual finishing race times within 0.2-0.4% over a variety of distances.
Training consisted of “steady” continuous running, tempo runs, 1-2 higher intensity sessions at 95-100% V’02 max, interval or repetition sessions at the track or cross-country, and two weight training sessions weekly. Total mileage increased considerably over her career from less than 25-30 miles initially to 120-160 miles per week during full marathon training in the final years.
It’s difficult to pinpoint one thing that specifically creates an exceptional athlete although running economy, or enhanced exercise economy, is considered by many to be a critical component of success. Running economy is defined as the oxygen (O2) cost of running at a certain speed, or the O2 cost of running a certain distance. The more efficient we become the less oxygen we use, which means we can run further or faster with the same effort.
Radcliffe’s data demonstrate a 15% improvement in running economy between 1992 and 2003 suggesting that improvements in this parameter are very important in allowing a distance runner to continue to improve their performance over the longer-term.
There is evidence that explosive strength training can improve running economy. Studies of runners that participated in strength training decreased their running pace by 4% as compared to runners who did no strengthening exercises even though there were no significant changes in their maximum aerobic capacity, blood lactate accumulation, body mass, or body fat percentage. This is an important finding because it suggests that the improvements in running economy come from a mechanism other than cardiovascular or metabolic changes. A possible explanation is enhanced mechanical efficiency and muscle recruitment patterns – both of which are a result of the neuromuscular adaptations achieved from strength training.
As Radcliffe’s weight training program became more sophisticated her leg strength and power improved. Her vertical jump test performance improved from 29 cm in 1996 to 38 cm in 2003 while lower body “flexibility” declined slightly. This corresponds to a suggestion that “stiffer” muscle-tendon structures might improve running economy by allowing a greater storage and return of elastic energy (something we’ll pursue further in the upcoming post).
Exercise economy is influenced by a wide variety of factors so it’s not easy to say this or that is directly responsible for the improved running economy experienced by Radcliffe over her career.
One suggested explanation offered by Jones is that our type I (slow-twitch) muscle fibres are more efficient than type II (fast-twitch) muscle fibres; that is, compared to type II fibres, type I fibres consume less O2 for a given amount of muscle work, and if endurance training causes a reduction in type II fibres being recruited, this would reduce the cost of O2 and, therefore, improve running economy. Alternative studies also suggest that, with chronic endurance training, type II fibres take on some of the same properties of type I fibres, or that this same training results in a transformation of type II fibres into type I fibres.
You might ask, do we care? Depending on your running goals, the answer would be yes since the type and quantity of training causes a definitive change to the muscle structure and can affect performance across the spectrum of distances.
The distinction is made in this paper that while a high V ̇O2 max is a prerequisite for success at the highest levels of elite runners, and Paula Radcliffe certainly had this, factors such as running economy and a delayed accumulation of lactate in the blood are also important and can be positively affected by our training.
Mr. Jones concluded the paper by saying,
“Study of the great human athletes therefore continues to provide insights into the ultimate limits to exercise performance. Through determination, commitment, and consistently hard training, PR has achieved her athletic potential and become one of the greatest endurance athletes of all time. I have been greatly honoured to have been associated with her.”
The upcoming post about muscle will include a behind-the-scenes kind of look at the types of training that create the most improvements for runners, strength vs mass, slow vs fast, elastic energy or active stretch, fatigue and endurance.
There would be no fartlek through the woods. No peaceful run down the mountain, and definitely none of those mind-numbing sprints around the track. In fact, there may be no substantive running at all this year. It’s shocking to the core.
If you’ve ever talked at length to a runner, chances are the discussion evolved into the topic of injuries. There’s not a single memory of an injury from the nearly 20 years of competitive tennis in my earlier years, but I can’t even put a number to all the running injuries.
You’d think it would be discouraging, but it’s not. The goal is to avoid injury, somewhat like the goal is to avoid misjudging your arrival at the airport and never miss a flight. It still happens sometimes.
This latest injury happened within the first two steps of a run when I heard a loud pop. It’s curious that I heard the pop despite music blasting into my ears, which I’ve later realized is because the pop came from inside my body. The peroneal tendon of my right foot had moved out of its groove. If it moved all the way across the ankle bone and snapped back, it‘s called Peroneal Tendon Subluxation. Treatment seems to be the same nonetheless. REST.
One authority on the subject claims this injury is one of the few running injuries that’s not a consequence of overuse. They correctly observe that some athletes experience this ailment even when we’ve followed all the proper training rules. The alternative label appears to be “repetitive use with biomechanical dysfunction” because those of us with high arches that also run excessively are more prone than others to succumb to its ill fate.
Initially it hurt to do everything. The back of my heel was swollen, the tendon was tender to the touch, and would move around slightly. It was during these early weeks that it hurt to walk, run, or even ride my bike. Some weeks I did nothing at all. It was depressing, frustrating, and every other aggravating ‘-ing’ word imaginable.
My husband told me one day that I needed to get out there and do something to exhaustion. We found a new bike route and I went for a long ride. There were the steepest hills I’ve ever climbed, nail-biting descents, and the hairiest of all hair-pin turns. I used every gear in my arsenal that day. It was exhausting.
I’ve learned something. I love running so much.
I love the long runs, and the total exhaustion that comes from a grueling race. I simply adore the daily routine of charging up my watch and following a training plan. I miss all those things that runners learn to endure over years of practice.
The advice I’d want to give to every new runner is to stick with it. It gets better. It doesn’t always hurt. Focus on training your mind, and some day you’ll be pleasantly surprised that you’ve actually enjoyed yourself.
Exactly the conversation I’ve finally had with myself about doing every other exercise besides running.
For more information about a peroneal tendon injury or the dreaded subluxation, click on one of the articles below.
We’ve lived life in 975 square feet for about four months. I expected to give cottage life a definitive thumbs up or down within the first few weeks, but surprised myself when I couldn’t muster a decision. My husband was decisive early on, but only because he didn’t want to move again. So it’s up to me I guess to tell the truth.
There’s not a level floor-wall-door-surface in all 975 square feet. In past years that would have made me nuts. Maybe it’s age, or acceptance, but I actually coached the workers to hang some of the doors out of level so they appeared level to the eye. We’ve done the same thing to shelves, pictures, mirrors. . . you name it. I hardly notice anymore.
The size of the rooms were an adjustment, but there’s a full stop choke point in the center hallway. It’s bad enough if my husband and I happen to be there at the same time, but add Mr. Boggs to the mix and it’s a total impasse.
I guess we’d both agree it’s the bedroom, or more specifically the bed that was the biggest change. Having spent decades in king quarters, a queen’s bed is just shy of enough, especially when one of us is in the middle of menopause. Of course, we’d be fine if not for Bentley (the dog). There’s not enough muscle in the world to move a dog that doesn’t want to move over – no matter how small he may be.
Our long-term plan is to add a garage, a guest suite, and a proper driveway. We want to paint the dark wood in the living room, upgrade the refrigerator, and bring over our own furniture, including my piano. Every day I debated whether to trade the baby grand piano for an upright so we’d have room for a dining table, or forego a dining table altogether. It was a brutal decision.
This was the only room in the cottage that could hold my piano, or a dining table. That’s Bentley in the center hall above, and Mr. Boggs in the picture below.
There’s lots of things that make this little cottage wonderful. It’s cozy, and full of character. When you settle in for the night, or wake up in the morning, it’s almost cocooning. Cleaning is a breeze instead of a chore, and there’s some amount of time spent every day rocking on the front porch. Folks walk by and stop to say hello. They tell us what a transformation the little place has gone through, or how they grew up with the original owner’s kids. And we won’t forget, it sits beside a native garden. It’s like walking into another world.
Then summer arrived.
Lake Junaluska is a beautiful resort that comes to life in the summer. The lake is at the end of our street where there’s canoeing and kayaking, a 3-mile trail around the lake, a gym, fishing, tennis, swimming pool, shuffle board, mini-golf, ice cream stand, coffee shop, a playground for the kids, and a labyrinth for contemplation. Once a week there’s a community bonfire, an outdoor movie, and concerts.
The 4th of July parade shut down Lake Shore Drive followed by a picnic for just $5, and fireworks after dark. There’s half a dozen gardens throughout the resort with guided tours every Tuesday. Bands played in front of the gardens on the 3rd of July tours. Forty-nine people toured the native garden next door to our cottage that day.
I went back to our larger home one morning to water the plants. It was quiet and peaceful. The neighbors are separated bynearly an acre of land. There’s no pending construction, no further renovations, all the furniture is in its rightful place. There’s room for my piano, and a dining table.
I realized I couldn’t bear the thought of living through the construction, and the little cottage couldn’t be perfect without it. I wasn’t sure about the crowds, or whether the entire neighborhood would hear me play the piano, and every wrong note that might ensue.
We moved back home a couple of weeks ago.
I wrote in a previous post that this little cottage has tormented me every day since we met. The torment continues. My husband was ready to live out his days there, “snug as a bug” as he would say. In the end, I was the one that panicked.
When we were settled back comfortably in our larger home, he (once again) declared he would never move again.
THE BRAIN is what makes us human. It gives us the capacity to make decisions, produce rational thoughts, or spectacular works of art. It’s responsible for our personality, storing the memories we cherish, and how we view the world. It also governs our ability to speak, eat, breathe, and move.
Disciplined, smart training is the foundation of any athletic endeavor, and proper training is also what earns us a seat at the table of endurance. Some athletes have genetic endowments and natural advantages that predispose them to sports. Maybe they respond better to training, the shape of their bodies or the genes they carry make them specifically optimized for certain athletic endeavors. Another subset of great athletes also have cultural and environmental advantages, such as the Kenyans who spend a lifetime being active at altitude. Then there are great athletes who have none of these advantages – the only common denominator between all groups of athletes being the brain.
The question of this post is not what can the human body do, but rather, what more can the human mind add to that?
The 1922 Nobel Prize in Physiology or Medicine winner, Archibald Hill, proposed in 1924 that the heart was protected from anoxia (absence of oxygen resulting in permanent damage) in strenuous exercise by the existence of a governor. Dr. Timothy Noakes, a professor of exercise and sports science at the University of Cape Town, re-introduced Hill’s governor model in 1997 on the basis of modern research. The essence of Noakes’ original central governor theory is that the brain monitors activity, predicting outcomes, and involuntarily implements an appropriate pace that prevents total exhaustion and permanent bodily damage by creating the distressing sensations we interpret as fatigue.
Physiological catastrophes can and do occur in athletes, however, that present conflicts in the governor theory. A story from the 2015 Austin Marathon serves as one example from many.
Kenyan runner, Hyvon Ngetich, had been leading most of the race. With two-tenths of a mile left to run, she began to wobble and stagger, and eventually fell down. After failed attempts to get up, Ngetich crawled to the finish line leaving her knees and elbows bloodied and hands stained from the pavement. Ngetich crossed the finish line in third place with a time of 3:04:02, and was immediately treated for dangerously low blood sugar. In a post-race interview with CNN, she said she didn’t remember finishing the race. She had continued the race despite the distressing sensations of fatigue and debilitating physiological failure.
Over time the central governor theory has been revised to include the role of psychological and motivational factors, which is where we begin to uncover the story of endurance.
muscular endurance: the ability of a muscle or group of muscles to repeatedly develop or maintain force without fatiguing.
cardiorespiratory endurance: the ability of the cardiovascular and respiratory systems to deliver blood and oxygen to working muscles, which in turn enables the working muscles to perform continuous exercise. It is an indicator of a person’s aerobic or cardiovascular fitness.
athletic endurance is defined as the ability to continue an activity despite increasing physical or psychological stress, as in the effort to perform additional numbers of muscle contractions before the onset of fatigue.
The human brain weighs about 3 pounds (1.4 kilograms). The surface area is 233-465 square inches (1500-2000 cm2), or roughly the size of one to two pages of newspaper. If we flattened the brain’s 1/4 inch thick outer layer, it would cover the size of an office desk. But to keep the brain compact enough to fit into our skull, it folds in on itself.
The simplest commands of the brain are monosynaptic (single connection), like the knee-jerk reflex. The knee-jerk response is a muscular jerk that happens quickly and does not involve the brain. There are lots of these hardwired reflexes, but as tasks become more complex, the circuitry involved is more complicated, and the brain gets involved.
The cerebellum, “little brain”, consists of both grey and white matter, and is responsible for coordinating muscle movement and controlling balance by transmitting information to the spinal cord and other parts of the brain. The cerebellum is constantly receiving updates about the body’s position and movement. It also sends instructions to our muscles that adjust our posture and keeps our body moving smoothly.
The cerebrum is the largest part of the human brain, controlling memory, movement, speech, emotions, and voluntary motor activities. With the assistance of the cerebellum, the cerebrum controls all voluntary actions in the body. Voluntary actions include running, clapping your hands, or lifting weights – things you are consciously doing.
The cerebral cortex is the outer layer of the cerebrum and consists of gray matter. This is where our conscious thoughts and actions take place; many of the signals our brain receives from our senses are registered in the cerebral cortex.
Basic life functions, such as heart rate, breathing, and blood pressure, is carried out by the brain stem. It regulates whether we feel tired or awake, as well as coughing, sneezing, and swallowing. The brain stem is the body’s “autopilot”.
About the size of a pearl at the base of the brain, the hypothalamus regulates physiological processes, such as blood pressure, heart rate, body temperature, cardiovascular system function, fluid balance, and electrolyte balance. This portion of the brain plays a vital role in maintaining homeostasis: the process of maintaining the body’s equilibrium by monitoring and adjusting physiological processes. It also influences emotional responses, sleep, appetite, and tells the skin to produce sweat when it’s hot to keep you cool.
The hippocampus (HC) region of the brain deals with the formation of long-term memories and spatial navigation. In diseases such as Alzheimer’s, the hippocampus is one of the first regions of the brain to become damaged, which leads to memory loss and disorientation.
The atrophy rate of the hippocampus (HC) is shown to be 2-3% per decade (Raz et al., 2004, 2005), and further accelerated to an annual loss of 1% over the age of 70 (Jack et al., 1998). Recent research, however, has shown the HC is among a few regions of the brain that generate new neurons.
In particular, exercise causes hippocampal neurons to pump out a protein called brain-derived neurotrophic factor (BDNF), which promotes the growth of new neurons. Higher cardiorespiratory fitness levels (VO2 max) are associated with larger hippocampal volumes in late adulthood, and larger hippocampal volumes may, in turn, contribute to better memory function (Erickson et al., 2011; Szabo et al., 2011; Bugg et al., 2012; Maass et al., 2015). (22)
Running Fact:A study published in the Journal of Neurobiology of Learning and Memory finds that running mitigates the negative impacts chronic stress has on the hippocampus region of the brain. “Exercise is a simple and cost-effective way to eliminate the negative impacts on memory of chronic stress,” according to the study’s senior author, Jeff Edwards, associate professor of physiology and developmental biology at BYU.
THE PERSONALITY OF A RUNNER
Observational studies have identified common personality traits among runners, including a strong vision, focus and resilience. Runners consistently exhibit mental toughness, an extraordinary capacity to plan ahead, and the ability to handle unexpected problems with a calm yet competitive demeanor; we are more willing to accept feedback, and acknowledge our mistakes.
Imaging of a runner’s brain show connections in areas required for higher-level thought, including more connectivity between parts of the brain that aid in working memory, multi-tasking, attention, decision-making, and the processing of visual and sensory information. Less activity is noted in a part of the runner’s brain that tends to indicate lack of focus and mind wandering. (24)
A 2009 study found ultra-marathoners were less dependent on rewards (self-motivated), they were more individualistic, and, not surprisingly, exhibited a far greater tolerance for pain. Studies of older runners show them to be more intelligent than their non-running peers, more imaginative, self-sufficient, reserved, and forthright.
The most common trait among runners of all ages is the belief that they possess the resources needed to achieve their own success. (13) (14)
Running Fact: An abstract presented at the 2018 American College of Sports Medicine Conference indicate runners who exhibit ”perfectionist” tendencies were 17 times more likely to suffer an injury that forced them to miss training as compared to other runners.
When we exercise, the brain recognizes this as a moment of stress, and invokes a “fight or flight” response. The body’s protection mechanism to this new threat is to release the BDNF protein in the brain. The greater the exercise intensity, the more BDNF proteins are released. At the same time, endorphins, another stress-reducing chemical, is released in the brain. The main purpose of the endorphins is to minimize discomfort and block the feeling of pain, sometimes also associated with a feeling of euphoria.
As exercise continues, physiological changes are signaled to the brain, such as body and skin temperature, increased heart and breathing rates. These signals are interpreted by the brain and compared with previous experience to determine allocation of resources.
The brain begins to change as soon as the athlete begins a sport, and the changes continue for years. In just one week, athletes develop extra gray matter, and different regions of the brain begin to interact – some neurons strengthen their connections to other neurons as they weaken their connections to others.
After deciding on a specific goal, to run a fast lap around the track for example, several regions of the brain collaborate to determine the best course of action to complete that goal. Initially, neurons in the front of the brain (the prefrontal cortex) are active; a region vital for the top-down control that enables us to focus on a task and consider a range of responses. By predicting what sensations should come back from the body if it achieves the goal, the brain can match the actual sensations received and revise its plan if needed to reduce error. With practice, however, the prefrontal cortex grows quiet; our predictions get faster, more accurate, and the brain becomes more efficient, learning to make decisions sooner.
In just a few sessions of exercise we become stronger, but not because our muscles have suddenly increased in size. The initial gains that take place are neuromuscular adaptations: the brain gets better at communicating with the muscles, using more of them, and using them more efficiently. The brain also learns to tolerate heat, lack of oxygen, and muscle pain. It becomes better at suffering. In essence, the brain is changing.
Neuroplasticity, or brain plasticity, is the process in which your brain’s pathways are altered as an effect of environmental, behavioral, and neural changes. Neuroplasticity occurs as the brain deletes connections that are no longer necessary or useful while strengthening the necessary ones. Which connections are pruned and which are strengthened depends on life experiences and how recently connections have been used. Neurons that grow weak from underuse die off while new experiences and learning new things strengthens others. In general, neuroplasticity is a way for your brain to fine-tune itself for efficiency. To learn new tasks, you need good plasticity.
Neuroplasticity affects both short-term memory (chemical changes) and long-term memory (structural changes). Initial changes in the brain’s structure take place quickly, showing immediate results. These changes are imbedded in short-term memory, but to transfer these changes to long-term memory requires more time (practice). It takes time and repetition for the brain to re-wire new connections, or pathways, that create long-term learning.
Practice is not a new concept for athletes. Distance runners build mileage gradually to teach their bodies to endure long distances, and then we practice these runs until our body transfers the distance to long-term memory. Sir Roger Bannister learned to run the 4-minute mile in the same way. He reduced the race to its simplest common denominator – 400m in one minute or multiples thereof, and trained until running 400m in a minute, 24 km per hour, became automatic.
The third way the brain changes is in function – how and when neurons are activated. Although each of these changes can take place in isolation, chemical, structural and functional changes typically work in concert to facilitate learning.
Fun Fact:Neuroscientist Charles Limb and others have scanned rappers’ brains during a freestyle rap and during a memorized rap. The studies show that during freestyling, there’s a functional change in their neural networks. Through practice, the rappers have reorganized their brain activity, allowing their improvised lyrics to bypass many of the conscious-control portions of the brain, which regulate behavior.
The greatest discovery regarding neuroplasticity is that nothing affects the brain more than our own behavior, and nothing is more effective than practice to help you learn. In fact research shows that increased difficulty, or increased struggle during practice actually leads to more learning and greater structural change in the brain. These studies have also identified the best methods to prepare, or prime the brain to learn include brain stimulation, exercise, and robotics. (33)
The important take-away, something confirmed from cancer treatments and the study of stroke victims, is that the way our brain functions is unique to each person. It goes beyond the fact that we all learn differently. Every human brain processes commands, makes connections, and functions differently. So the common denominator in learning is practice.
Skill athletes (basketball players, dancers, gymnasts, figure skaters) show greater motor cortex plasticity while endurance athletes (cross-country skiers, orienteers, runners) show enhanced plasticity in task-unrelated brain areas.
Motor Cortex Plasticity In Action: Giannis Antetokounmpo’s slam dunk.
In a blatant show of coordination and focus, Antetokounmpo snared the ball mid-air with his right hand while soaring over the head of Knicks’ guard Tim Hardaway Jr. without seeming to notice the obstacle at all – and then slammed the dunk.
THE LIMITS OF HUMAN ENDURANCE
Fatigue refers to the inability to continue exercise at a given intensity. In all sports and exercise training, the onset of fatigue varies depending on a person’s fitness level, exercise intensity, duration, and environmental conditions (e.g., heat and humidity). Fatigue develops over time, but is largely dependent on duration and intensity.
There are two distinct types of fatigue: central and peripheral. Central fatigue (also called Central Nervous System fatigue) involves the brain and spinal cord rather than the muscles. Central fatigue happens in the regions of the brain involved with mood, emotion, and psychological arousal. This is why being psyched, such as during competition, can help performance, but is also why fatigue, like pain, is relative.
With central fatigue, the brain becomes unable to send enough signals to the muscles to maintain optimal muscle activation, resulting in general body fatigue (tiredness, loss of drive, sleepiness, etc.) and reduced muscle force.
Peripheral fatigue results from the muscles becoming fatigued. A lack of resources within the muscle results in the accumulation of lactic acid, causing a burning sensation and fatigue within the muscle. Although both central and peripheral fatigue result in decreased performance of the muscles, they follow different mechanisms.
The question is, how much can you separate the two? It’s hard to distinguish central fatigue (the brain) from peripheral fatigue (the rest of the body) because the brain tends to influence everything, and is in turn influenced by everything.
THE CENTRAL GOVERNOR
Although fatigue produces the belief that our resources are limited, exercise generally ceases before the muscles are depleted. In fact, in all forms of exercise fatigue develops before all skeletal muscles are recruited. Just 35-50% of the active muscle mass is recruited during prolonged exercise (Tucker et al., 2004; Amann et al., 2006), and even during maximal exercise this increases to only about 60% (Sloniger et al., 1997a,b; Albertus, 2008).
Muscle biopsies from cyclers revealed that intramuscular measurements were no different at exhaustion compared to rest, and that these (ATP) levels never dropped below 50% of resting concentrations at any time during the exercise bout, suggesting fatigue causes people to terminate exercise well before muscle energy reserves are depleted (Noakes & Gibson, 2004; Parkin, Carey, Zhao, & Febbraio, 1999).
This supports the updated theory that fatigue is a central (brain) perception – a sensation or emotion – and not a direct physical event. Exercise seems to be regulated in anticipation to insure biological failure never occurs (in healthy humans).
Based on studies done at the time, this new definition of fatigue supported the idea that a central governor reduces the mass of muscle recruited during prolonged exercise gradually to prevent the development of muscle glycogen depletion and muscle rigor, or of hyperthermia leading to heat stroke. In other words, fatigue is one way the brain protects the body and preserves homeostasis by regulating power output – what runners will recognize as pacing.
If fatigue is an emotion, it will (like pain) be perceived differently by different people. Ultimately, the Borg Scale of Perceived Exertion was developed, which matches how hard you feel you are working to a “relative” scale of numbers from 6 to 20. The physical sensation of fatigue increases along the Borg RPE scale as a linear function of exercise duration. Maintaining a strategy that follows this linear increase of effort has been thought to produce the optimum pacing strategy (start slow/easy, finish faster).
The Borg RPE scale has since been described as the manifestation of information about body temperature, oxygen levels, fuel storage, and the more subtle indicators like mood or how much you slept last night. Perceived effort (RPE) gradually increases based on a combination of these psychological and physiological changes. Runners probably don’t consciously correlate pacing to the Borg scale, however, and researchers disagree as to the extent pacing decisions/computations take place consciously and voluntarily or unconsciously and automatically. Where they do agree is on effort: how hard it feels dictates how long you can sustain.
Understanding how we control the feeling of effort is still being studied, especially as it relates to pacing. Two concurrent studies recently looked at pacing methodologies. One uses an effort-based approach where runners increased pace based on self-determined effort rather than the traditional approach of pre-set increments along an increasing scale (start slow/finish faster). The effort-based subjects reached higher VO2 max values. This study, by Alexis Mauger, was co-published in the British Journal of Sports Medicine alongside another study (by Noake’s student, Fernando Beltrami) which used a “reverse” protocol that started fast and gradually slowed. This protocol produced higher than “max” VO2 max values.
Alex Hutchinson aptly summed up these conclusions in his book Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance, ”If you execute a perfectly paced race, that means you effectively decided within the first few strides how fast you would complete the full distance. There’s no opportunity to surprise yourself. . .”
Once exercise begins, pace is continuously modified by continuous feedback to the brain from conscious sources including information of the distance covered (Faulkner et al., 2011) and of the end-point (duration and intensity). Studies show an athlete’s perceived exertion can be positively influenced by knowing the duration of an exercise bout, and that energy is held in reserve and available for an end-spurt regardless of their rating of perceived exertion (RPE). (27) (28).
Other conscious deceptions that improve performance and positively impact RPE include sudden noise, music, seeing the finish line or an encouraging smile, rinsing the mouth with carbohydrate (without actually ingesting the fluid), being provided with inaccurate information by a clock that runs slowly, or the pace of a prior performance that had been deceptively increased by 2%, and a host of psychological factors, including hypnosis.
Interestingly, just swishing a glucose solution in the mouth led to improvements in 1-hour cycling performance, whereas intravenous infusion of glucose did not (Carter, Jeukendrup, & Jones, 2004.) These effects are probably not specific to glucose; recent evidence suggests that simply handling ibuprofen without ingesting it promotes pain relief, for example (Rutchick & Slepian, 2013). Glucose is absorbed almost entirely in the gut, so it would be impossible for glucose briefly swished in the mouth to cause an increase in available blood glucose (Gunning & Garber, 1978). Instead, the presence of glucose in the mouth may simply provide an anticipatory signal of glucose availability, which leads some experts to argue that the body’s glucose resource issue is one of allocation, not of limited supply. (32)
The Greatest Human Strength
RPE prevents the athlete from continuing exercise at a given pace when it might cause bodily harm. This anticipatory regulation, or pacing, balances the desire for optimal performance with the requirement to defend homeostasis. You may not even notice the body’s regulatory reaction at first, but gradually the effort required to sustain a given pace increases. Ultimately, exercise is terminated when the perceived effort reaches a level that is considered higher than the perceived benefit. (25) This conscious decision of whether to maintain, increase or decrease the current workload or indeed to terminate exercise altogether may be the outcome of a balance between motivation and the sense of effort.
One of the most obvious characteristics of human exercise performance is that athletes begin exercise at different intensities, or paces, depending on the expected duration of exercise – a bout of short duration is begun at a much faster pace than one of longer duration. Also, athletes typically run harder in competition than in training. The point is that athletes always show an anticipatory component to their exercise performance that seems to be influenced by neural mechanisms relating to willpower (self-control), motivation and belief.
In 2013, at 64 years old, Diana Nyad set out to be the first person to swim from Havana to Florida without a shark cage. A marathon swimmer can expect chafing, nausea, severe shivering and hypothermia, swollen lips, an irritated mouth, diarrhea, extreme weight loss, and sleep deprivation. At the peak of her strength, age 28, she tried but failed to complete this swim. She later said: “I never had to summon so much will power. I’ve never wanted anything so badly, and I’ve never tried so hard.” Coming back to the sport 30 years later, she claimed, “I thought I might even be better at 60 than I was at 30. You have a body that’s almost as strong, but you have a much better mind.”
Nearly 53 hours after jumping into the ocean in Havana, Nyad finished the 110-mile (180 km) swim; her fifth attempt since 1978 and the fourth since turning 60. In one interview she said, “ — you tell me what your dreams are. What are you chasing? It’s not impossible. Name it.”
Research has suggested that self-control relies on a limited resource – that it unfortunately appears to wane over time similar to a muscle that becomes fatigued with overuse. Humans are less willing to exert effort the longer they have already exerted effort. This so-called ‘ego depletion’ effect has been supported by over 200 separate studies, which show that repeatedly resisting temptation drains your ability to withstand future enticements. With the right motivation, however, it appears you may be able to persevere even when your willpower strength has been depleted.
Motivation combines internal and external factors to stimulate the desire and energy to be continually interested, committed to, or make an effort to attain a goal. It is the result of conscious and unconscious factors such as the (1) intensity of desire or need, (2) incentive or reward value of the goal, and (3) expectations of the individual and of his or her peers. These are the reasons we behave in a certain way. (35)
When motivational arousal is high and must be concentrated within a brief period, the intensity of motivation must also be great. It is the difference, for example, between moving 100 pounds of books one book at a time or all at once, or running an all-out 400m challenge versus enduring a 10,000m race or marathon. Motivation tends to increase as the difficulty of the task increases until the required effort is greater than is justified by the motive – or the required effort surpasses the individual’s skills and abilities. At this point motivational arousal drops. We can see this play out time and again on the marathon course where runners find the reward of finishing the race no longer surpasses the pain of continuing to run.
An increasingly accepted body of exercise physiology has emerged that looks to psychology to understand endurance. This ‘psychobiological model based on motivational intensity’ theory (Brehm and Self, 1989; Gendolla and Richter, 2010) suggests that perception of effort and potential motivation are the central determinants of exercise duration, with people consciously deciding how much or how little effort to apply based on a number of considerations. These new studies suggest endurance is strongly influenced by the manner in which the brains of runners generate the sensations of fatigue.
Remember that fatigue is an emotion entirely self-generated by each athlete’s brain, and therefore unique to each individual – or illusionary. Based on this model, the winning athlete is the one whose illusionary symptoms [of fatique] interfere the least with actual performance.
But psychologists have also found evidence among athletes in what they call “self-efficacy,” or a belief in their own competence and success. This is where self-efficacy converges with the placebo-effect.
Studies repeatedly confirm that interventions such as sugar pills, ice/cold/lukewarm baths, massage, caffeine, beet juice, altitude training, or even a “lucky” ball, in the case of golfers, improve our game. Athletes everywhere swear by them, yet science repeatedly proves the effects are null or ambiguous at best.
Christopher Beedie, a sports psychologist at the Canterbury Christ Church University in England, is among the few scientists who study the placebo effect in athletics. His work often examines how elite athletes perform under intense fatigue when they think they have some kind of performance enhancement.
Beedie recently finished the largest placebo study ever done in athletics—600 subjects in all—and found that the people most likely to respond to placebo were the ones experienced using supplements. Perhaps the previous supplements the athletes had taken primed them to have a placebo response, or maybe athletes who naturally respond to a sports placebo are also likely to have taken performance enhancers. Either way, it suggests that artificially boosted performance and performance boosted from expectation produce similar effects. In some cases, athletes performed better when given a sugar pill than the athletes that were given certain performance enhancing drugs.
Even in the arena of these performance enhancing drugs and placebos, especially for elite athletes, there’s a limit to the benefits of both psychological and pharmacological performance enhancers, so why not just use belief instead? “We’re trying to educate athletes into the idea that the headroom is there to be filled, and drugs are not necessarily the only way of filling that headroom,” Beedie says. “Confidence is the drug of champions.”
In the end, the question we all share is how do we go further/longer/faster; what is the secret of endurance?
Dr. Lara Boyd, Director of the Brain Behaviour Lab, is a physical therapist and a neuroscientist leading the effort to understand what therapies positively alter patterns of brain activity after a stroke. In a research-based TEDx Talk, Boyd describes how neuroplasticity gives you the power to shape the brain you want.
The new discovery is that learning changes our brains differently. My brain will go about learning a new task differently than your brain will learn the same new task. Understanding these differences, these individual patterns, is the future of neuroscience – and possibly sports science as well.
Boyd suggests we understand how we learn. What is it that your brain responds best to? For runners learning to endure, maybe this means experimenting with self-talk, visualization, or forcing yourself to try a new training approach altogether. Coaches are increasingly realizing they can push athletes to new limits just by asking them to do something they didn’t think they could do.
Even when athletes were sufficiently motivated, by monetary rewards or recognition for example, they did not perform as well as athletes who were led to believe they could accomplish the task.
Humans keep doing impossible things. Running a 4-minute mile, running 100 miles, lifting 500 pounds over our head, being an undefeated wrestler with no arms or legs. Each of these things have been accomplished even though public opinion claimed they were impossible at the time. The difference was that in each example these people believed, or were tricked into believing they could do this thing.
The pursuit of endurance is a unique journey for each of us, but it seems science has concluded what athletes have known all along – that there’s more in the tank, if you’re willing to believe it’s there.
A 2017 animal study published in the journal Behavioural Brain Research concluded that a sprint interval training regimen, rather than intensive endurance training regimen has the potential to improve anxiety and depression through a greater increase in (brain-derived neurotrophic factor) contents in the brain.” (10)
A NOTE ON MUSIC: Diversionary techniques to distract the mind, such as listening to music or self-talk, were discussed in a previous post on Pain, and have proven effective in lowering the perception of effort. Music, in particular, can narrow attention and divert the mind from the sensations of fatigue. However, this holds true for low and moderate exercise intensities only; at high intensities, perception of fatique overrides the impact of music. At high intensities, the physiological feedback to the brain regarding things like respiration rate or blood lactate accumulation dominates the conversation, and music fails to divert the mind from the body’s feedback. Listening to music seems to shape how the mind interprets symptoms of fatigue, however, which may enable athletes to perform more efficiently resulting in greater endurance. (16)
Studies demonstrate that running economy significantly changed, along with perceived effort, based on whether the runners knew they were running 20 minutes or whether they did not know the duration, even if they ended up running 20 minutes.
In a recent study published in BMC Medicine, the 64-day ultramarathon TransEurope FootRace Project followed 10 ultra-endurance runners covering about 4,500 km from Bari, Italy to the North Cape, Norway recording a large data collection of brain imaging scans. This study indicates cerebral atrophy among the runners amounted to a reduction of approximately 6% throughout the two months of the race, but was completely reversed within the 6-month follow-up. The results of this unique study, which revealed no brain lesions, gave clues to the effect of extreme fatigue with energy deficits on cortical grey matter volume. Having an understanding of what the brain does during an ultra-marathon event could help refine research on the matter of mind over muscle in determining exercise tolerance in endurance athletes, but may also benefit military personnel involved in physical work over prolonged periods and patients affected by unexplained chronic fatigue syndromes.
A 2011 study (Erickson et al.) demonstrated that 1 year of aerobic exercise increased the volume of the hippocampus by 2% in elderly adults, while controls who underwent 1 year of stretching exercises exhibited a 1.4% decrease in hippocampal volume.
Kids who participated in vigorous physical activity scored three points higher, on average, on their academic test, which consisted of math, science, English, and world studies. (23)
Telling runners they look relaxed makes them burn measurably less energy to sustain the same pace. Giving rugby players a post game debriefing focused on what they did right rather than what they did wrong had effects that continued to linger a full week later. (34)
The lull in anatomy ended several months ago. This only means my days have once again been filled with reading – reading books, re-reading books, and weeks of days spent delving into the far reaches of the internet in search of the latest revelations on the runner’s brain.
It would be a fair assumption to think this post will ooze facts about all the positive benefits running gives back to your brain. The benefits are countless and noteworthy, but my curiosity lies more in what the brain contributes to our running, or our capacity to keep running. In other words, has anyone confirmed whether the brain controls or limits endurance?
Early studies concluded it was the heart itself that became fatigued, which resulted in too little blood being supplied to the skeletal muscles and brain. Running all out at our fastest pace for several minutes could make us all support this theory, but the heart does not fatigue. This realization led to the idea of a governor that terminates exercise before maximal blood flow to the heart is achieved and the heart is damaged. The supporting data suggested that a governor somewhere within the body terminates exercise before the heart and skeletal muscles are forced to contract anaerobically (without oxygen). These notions persisted and evolved for a long time.
The central governor theory has ultimately come under attack with compelling arguments. One scientist observed that with the exception of combat activity, sport is perhaps the brain’s biggest challenge, requiring more cognitive skills than is often appreciated.
The ability to plan and execute performance, make corrective adjustments to behaviour (e.g., modify skill execution or pacing strategy), resist temptation, manage emotions, elevate collective obligations above myopic self-interests, and persevere despite disappointment all constitute acts of self-control (or self-regulation) implicated in successful sports performance (Friesen, Devonport, Sellars, & Lane, 2013; Hardy, Jones, & Gould, 1996; Tamminen & Crocker, 2013). This is one of the lines of thinking that gave us a new term, ego depletion, and a string of new theories about the limitations of endurance.
I’ve contemplated abandoning the brain several times. There are other anatomy posts I could churn out in an afternoon, and I’d much rather move on to the creative side of writing. Instead, the typical routine is to do my research in the late afternoon while my husband reads or watches the news. Some days, the world seems to be in total chaotic calamity in the background noise of the news – all the while I needle my way through the theories of endurance.
It was a breakthrough day when I came up with an outline from the 25 pages of research notes I had collected. Then I found a thesis written in 2016 by a Doctor of Philosophy student at the University of Wolverhampton. The author presented research from four studies that examined self-control in sport, and co-authored two additional studies that explored emotion as a factor in the self-regulation of endurance. The best news of this discovery was that it’s written in plain English, and presents the studies and opposing arguments of the studies already in my research notes. Even better, all of the studies’ control subjects were athletes, and in one case they were competitive endurance runners. The bad news of this discovery is that the thesis is 292 pages long. The reading phase begins again.
It’s fairly typical for me to regurgitate my research at the end of the day over a glass of wine with my husband. Sometimes it just helps to talk about it and get it out of my head, but mostly his reactions help me sort through the data. He reminded me one day how few people experience the feeling of pushing their body to the point that the brain would shut them down. And there may be fewer people still that observe this shutdown on a personal level in someone else. It’s a humbling experience on both sides, but as he said, the experience almost always leaves the athlete more confident and empowered.
I presented several questions in a previous post about the heart: Do the muscles fatigue and reduce their output because the body has reached its maximum potential to deliver oxygen? Does the heart force the muscles to reduce output because it senses a lack of blood flow (oxygen) and works to protect itself? Or, does the brain anticipate when the blood and oxygen supply to the heart is about to become inadequate and reduce the recruitment of the muscles causing exercise to diminish or cease (fatigue) before damage is incurred to the heart or skeletal muscles?
Even if we acknowledge the body’s central governor must be found in the brain, and thereby controls the mechanisms that dictate endurance, this simply raises more questions. Stress, will-power, emotion, fatigue, motivation, the placebo effect, and even personality traits originate in the brain and each one contributes to, or limits endurance. . . the brain is still under construction.
The headline promises that if we know this one thing, we will never, ever stop training. We’ve worked hard to become the super heroes we are today. We can run for hours, outpace a cheetah, or lift a VW Bug. Why on earth would we risk losing this for a few measly rest days we won’t enjoy anyway?
Exercising at least 30 minutes per day, five days a week for just over a week increases our plasma and blood volume. A few weeks later our heart rate no longer spikes, and we get better at dissipating heat through sweat. We feel more comfortable.
Then our heart gets better at pumping blood, capillaries increase so that more oxygen and nutrients reach the muscles, and now we can exercise even longer.
Keep going and we gain muscle mass, strength, and cardiovascular efficiency; after six months of endurance training, it’s possible to increase blood volume by as much as 27 percent.
Take just three days off and you lose that blood volume increase, and now your heart rate increases during exercise. Within two weeks, the amount of oxygen we can process drops by about a half percent each day. The brain’s ability to recruit muscle drops by one to five percent.
Three weeks off and the muscles begin to atrophy. The body increases its reliance on carbs rather than fat for fuel while simultaneously increasing its capacity to store fat. In other words, the body you had trained so efficiently to burn fat during those long runs can no longer burn fat – just as it also becomes easier to get fat. Excellent.
But even super heroes need rest.
Hans Selye first discovered how the body reacts to stress, including a set of responses he called the “general adaption syndrome,” and a pathological state from ongoing, unrelieved stress. Sports training theorists eventually used his ideas to explain why adequate recovery is an essential part of the athlete’s training program.
The General Adaptation Syndrome has three phases: Alarm, Resistance, and Exhaustion.
During a stressful training event, your body alarms you with a sudden jolt of hormonal changes which immediately equip you with sufficient energy to handle the stress. If the stress continues (exercise does not end) or recurs for a period of time, the body resists by making adjustments in its structures or enzyme levels to give it added protection against this specific type of stress. At this point rest must occur for repair/recovery and rebuilding to begin. Rest restores balance.
Problems begin to manifest when you find yourself repeating this process too often with little or no recovery – not enough rest days, time between speed sessions, or even recovery time between races. Ultimately this moves us into the final stage.
EXHAUSTION STAGE: At this phase, the stress has continued for some time. Your body’s ability to resist is lost because its adaptation energy supply is gone. Often referred to as overload, burnout, adrenal fatigue, maladaptation or dysfunction. Stress levels go up and stay up resulting in injury and/or illness.
The problem is that we don’t always completely recover between workouts. Some of the fatigue stays with us, accumulating slowly over time. A 2005 study of Olympic swimmers found fatigue markers still present in the rested athletes six months after their season ended.
In sport science, fatigue is the term used to describe the inhibition of maximal performance that comes about as a result of stressors imposed on the athlete. Although acute fatigue lets us know we’ve trained hard, cumulative fatigue is problematic.
It is generally believed the primary cause of training-induced fatigue is the total volume of a training program, and not nearly as much its intensity. This is likely because volume represents the amount of physical work being done, and thus energy expended and damage sustained by the body.
At the time of this writing, I’ve been working through an injury for several weeks. I had done everything by the book: a slow build-up in mileage, low intensity, adequate rest days, and I still got injured. I think cumulative, unresolved fatigue was the culprit.
For more than a decade, I’ve included a few days off from running here or there, but any extended time off was always spent cross-training to avoid losing fitness. That way I could easily transition back into marathon training. I had wanted to take time off at the end of last year, but maintained a minimum effort instead so I wouldn’t lose time in reaching this year’s goal. Executing years of back-to-back training plans (without complete rest breaks) takes a toll.
Dr. Tim Noakes wrote in his book, Lore of Running, “The body only has a finite capacity to adapt to the demands of intensive training and competition. Runners must choose, early in their careers, whether to spread that capacity over a long career, as did Bruce Fordyce and Ironman triathlete Mark Allen, or to use it up in a spectacular but short career, as did Buddy Edelen, Ron Hill, Alberto Salazar, and Steve Jones. This is the reality that both elite and non elite athletes must confront every day that they run.”
I’ve taken a fresh look at the value of the do-absolutely-nothing type of rest. If the point of rest is to restore homeostasis – a stable condition of equilibrium or stability – how is this accomplished if we rest from our primary sport only to spend that time cross-training hard in another sport.
Professional athletes take time off; sometimes a week or two of no exercise followed by a week or two of cross training. This provides the time needed for the body to completely heal without so much time off that detraining begins.
That article that claimed we’d never, ever stop training? The great takeaway was: you should never, ever stop training. . . for more than two weeks, if you can help it. My takeaway is that we should do what’s right for us – whether that’s two weeks or two months depends on your level of fatigue.
The beauty of a cottage garden is its artful irregularity. There’s nothing pretentious or disciplined in these small plots of land, but they are ingenuously designed nonetheless. I can picture a gardener throwing seedlings wildly from the threshold of her humble cottage where these self-sowing wonders create a magical kaleidoscope of perennial beauty. At least this is the vision for creating my own cottage garden.
The ’secret’ garden next door to our cottage attracts hordes of visitors as it turns out. Botanists, biologists, and students of all ages spend lazy afternoons studying the vast collection of plants. A photographer arrived every morning last week at precisely the same hour to capture the slow motion arrival of one particular flower. Bird watchers linger indefinitely, and folks from all around town make regular visits to watch the season unfold.
Virginia bluebells, yellow wood poppy, white dwarf crested iris, flame azalea, yellow lady’s slipper and several varieties of trillium bloom in spring, but there’s more than 500 different plant varieties that make an appearance throughout the year. There’s also a mixture of mature oak, black walnut, locust trees, an umbrella magnolia, and a rare bigleaf magnolia.
The Corneille Bryan Native Garden (I took the pictures this week with my iPhone):
Plants that have been precariously positioned at the edge of extinction have been brought to this low-lying ravine next door. Half of the world’s known shortia, a threatened herbaceous perennial, went underwater when the nearby Jocassee Reservoir was filled during the early 1970s. A species of grass of Parnassus, a flowering perennial, disappeared from Waynesville after a road-widening and repaving effort. A society of naturalists gave the garden 10 endangered conifers of the Torreya taxifolia species. All of these species now live in the garden.
There are also two rock-encased springs that were once used to keep food cool in the heat of summer. This one is at the base of the stream just before it reaches the lake.
Volunteers have identified every plant in the garden. The trillium, poppies, woodland phlox, and ferns are some of my favorites.
The garden had extended onto our property over the years, but the volunteers re-worked things a bit to give us enough room to add a driveway. This photo was taken from our front porch.