Another June has arrived and, as AJW would say, “It’s racing season!” For most runners focusing on early summer 100-milers, the training “hay is in the barn:” miles have been run, vertical logged, race-pace honed.
While physical training is critical, what may matter most for 100-mile race performance is how well a runner can self-preserve on race day, keeping it together, physically and mentally, from start to finish.
What many people recognize–yet fail to fully appreciate–is that the true race-day battle lies within ourselves, and between our ears. It is the brain that ultimately decides how far and how fast we can run.
Thus, managing the needs and concerns of the brain may be the ultimate key to peak performance, especially at the 100-mile race distance and the extreme demands it places on body and brain.
“The Selfish Brain”: The Central Governor Model
A decade ago, Tim Noakes, MD, first proposed a mechanism by which the brain mediates physical efforts. Previous theories suggested the skeletal muscle–its oxygen consumption (VO2Max) and work output–dictated maximum performance. Noakes’s model, the Central Governor Theory, proposes that it is the brain that dictates exercise intensity and duration in order to ensure its own survival.
The brain is inherently selfish: it only cares about itself. It will do anything necessary to ensure it gets a steady flow of oxygen and sugar, and a reliable mechanism for transport. That said, any physical effort that might jeopardize those values will be tightly regulated. If not, the conscious brain might team with the body to literally run itself to death by either destroying skeletal or cardiac muscle, or by starving the nerve tissue of sugar and oxygen.
Ultimately, The Central Governor, acting at various levels of subconscious (in similar fashion to the Board of Directors previously mentioned in pain mediation), makes decisions based upon myriad data, including:
- The present effort (monitored internally by various measures)
- The body’s current fitness
- Previous physical and psychological experiences (training and racing)
- The current environmental conditions (temperature, wind, humidity, terrain)
- The task at hand (race distance, intensity, competition)
The Central Governor takes in all that information and determines a pace that will ensure completion of the task at hand while ensuring physical safety of its fuel and blood supply, and physical integrity. It also establishes and monitors limits to physical integrity, and when the body begins to approach those limits, the Central Governor takes action.
According to Noakes, when exercise intensity and tissue stress to the heart, skeletal muscles, and nervous tissue “…approaches the limit of what is safe, the brain’s motor cortex, which recruits the exercising muscle, is informed, and it stops recruiting additional muscle.”
The result, he adds, is that the body experiences fatigue, and the work output of the heart and skeletal muscle falls.
In summary, the sensation of fatigue (and the pain accompanied, therein) and a slowing of pace are preemptive and protective, yet extremely powerful actions taken by the brain, to avoid real physical trauma.
This is easily understood by even the most novice runner: you run hard or long and you feel like you’re going to die. Yet within minutes of stopping, you feel fine. This is not because the body has miraculously repaired any damage; rather, when the brain perceives the threat of exertion has passed, sensations of fatigue (and pain) cease.
Experienced 100-mile racers know this and are hardened against the desire to stop. But the Governor isn’t going down without a fight. If you don’t stop, fatigue sets in with the express goal of stopping you, or at least slowing you down.
Says Noakes:
“Fatigue is a central brain perception, which is based on the sum of the sensory feedback from a variety of organs to the central governor, and which is expressed physically as the alteration in pacing strategy (running speed) caused by a reduction in the muscle mass activated by the motor cortex in the brain.”
Simply put, if you don’t stop, you will slow down. And if evidence of danger continues to mount, and you fail to listen to the Central Governor, it will stop you.
That said, the key to peak performance is to balance the needs and concerns of the Central Governor with your race goals, and to effectively deal with the protective fatigue it sends your way.
According to Noakes, the specific need of the Central Governor is:
“…internal body homeostasis… maintained so that the muscles do not develop ATP depletion and rigor during either high-intensity or prolonged exercise when muscle glycogen stores are depleted; that the heart does not develop myocardial ischemia during high-intensity exercise; that the body temperature does not rise too high; and that the brain is not damaged by continued exercise when the blood glucose concentrations are low.”
Serving The Governor: Critical Elements of 100-Mile Performance
Accepting Noakes’s theory, there are four primary physical elements that must be critically monitored during a 100-mile race:
- Heart rate
- Blood sugar
- Body temperature
- Muscle integrity
Those who can effectively manage those elements–and run with the Governor, rather than against it–stand the best chance at optimal performance.
Heart Rate, Pacing, and Micro-Pacing
The brain craves consistency and sustainability. These are the pillars to physical preparation, and they also play a vital role in managing race-day effort. The brain, according to Noakes, monitors cardiac integrity through myriad factors including heart rate.
Maintaining a consistent heart rate during race performance is critical in keeping the Governor satisfied. A heart rate that is too high for too long and too early will signal the brain, “What we are doing is unsustainable!” And it will shut you down.
Smart pacing is enormously important in 100-mile racing. A conservative early pace should sufficiently keep the heart rate at sustainable levels. Just what that level is depends on the person and the event.
It is generally accepted that sustainable efforts in ultra-endurance events (over six hours duration) range between 50 to 75 percent of heart-rate maximum (HRM). For most of us, this includes a heart-rate range of 110 to 160 beats per minute.
Be wary of sustained heart rates above 160 BPM (or above 75% HRM), especially early in the race. This quickly burns through vital sugar stores and provides “scary” feedback to the Governor about your current effort and its sustainability, or lack thereof. The more “scary information” the Governor receives, the more intense the fatigue it will send your way to slow you down.
Smart, even pacing–especially amongst today’s elite ultramarathon runners–seems to have become a lost art form. The competitive fire of these top runners pushes early-race paces to the brink, and the result is a second half “race of attrition” amongst the field.
It wasn’t always that way. In 2001, after his second place overall finish and 20th, sub-24 hour finish at the Western States 100, Tim Twietmeyer sat down with UltraRunning Magazine for an interview, and said this about pacing:
“At Western States, there’s not a lot of good terrain to run in the first 30 miles, but there’s a lot of good terrain in the last 30. I try to save my energy so I can apply it at a point in the race where I’ll get the maximum payback. Early in my Western States career I listened from the people that had been successful and the message was clearly to start slow because you’ll need a lot more energy and strength later in the race than you’d think.
I’ve always thought at Western States that you spend about 50 percent of the effort getting to the river (78 miles) and the other 50 percent getting from there to the finish line.”
This is a brilliant strategy for two reasons. One, it establishes a physical restraint on effort. Twietmeyer, who by then knew the course better than anyone in the race’s history, had a precise feel for pace and aid-station splits that allowed him to run sustainably and within his physical bounds.
But secondly and perhaps more importantly, he was telling the Governor that he was “only running 50 percent,” that he was not running hard. Perhaps it is this conscious brain argument with the unconscious that kept the Governor at peace, limited debilitating fatigue, and allowed for successful late-race running.
Tip: Know your pace and splits, and follow them.
Sustainable pacing comes from course knowledge and experience. However, if you have not run the course before, do some research on other runners’ splits, similar to your own ability, and adopt–and adapt–them to yourself.
A noteworthy example of this practice was Sage Canaday’s run at Lake Sonoma 50 in April of this year. While he’d never run the course, he researched Dakota Jones’ splits from the previous year, wrote those on his arm, and followed them closely. The result was the fastest–and most evenly split–race of the day. And it broke Jones’ course record.
Training and racing with a heart-rate monitor may also be an effective means of ensuring sustainable race pace, especially early. Heart rate ultimately trumps average speed and race splits since it takes into account changes in terrain and conditions.
Tip: Know how your heart rate responds to varying terrain.
I refer to this idea as “micro-pacing:” the ability to adjust effort to acute changes in terrain and conditions. Establish sustainable paces using heart-rate data on the flats versus hills, hot versus cool conditions, and high altitude versus low. When studying heart-rate levels, most runners would be surprised to realize:
- how low heart-rate can be running fast on flat terrain
- how high heart-rate can be on uphills
- how acutely high heart rate can spike on a steep, technical downhill
Having heart-rate data on various terrain and conditions can provide vital information for pre-race planning and race-day execution. Keeping heart rate and race effort sustainable will keep the Governor on board, and prevent mid- and late-race derailments.
Blood Sugar and Fuel
In his formative work sports hydration, Noakes makes a strong argument in Waterlogged about the over-emphasis on hydration during endurance events, and the dangers of over-hydration* on performance and physical safety.
(*It is worth noting that hydration was not a factor included by Noakes in his Central Governor model.)
But perhaps as important of a message was the recommendation for substantial and consistent blood-sugar levels during ultra efforts.
Exercise science has known for decades that sugar is crucial to peak performance. But exactly why still remains in question. In reviewing the literature, Noakes notes that the primary benefit of mid-race sugar intake is to ensure consistent energy for the brain. After four to six hours of running, muscle sugar stores are depleted, and the muscles must use fat for fuel. However, the brain continues to require a consistent energy source in the form of sugar.
Any decrease in blood sugar levels, especially after many hours of prolonged running, will result in hypoglycemia and cause a shocking and unequivocal response from the brain: The Bonk. The brain, in response to hypoglycemia, will shut you down faster and more fiercely than any other act by the Governor. No sugar, no brain. No brain, no gain.
For those of you lucky, rare few to never experience it, the symptoms of hypoglycemia include:
“a reduced ability to concentrate, a sudden feeling of weakness, and the intense desire to stop running. Typically, the athlete senses the impossibility of completing the race.”
The hypoglycemic response is perhaps the most powerful and miserable of the Central Governor acts. While certainly debilitating, it is reversible: the tales of mid-race resurrection commonly heard in ultras is proof that, once sugar is back on board, so is the brain.
The key to avoiding hypoglycemia is steady, consistent fueling. This is more difficult than it seems. Race day provides countless distractions and barriers to consistent fueling including terrain, environment, pace, competition, and mood. These factors often interfere with our best-laid plans for consistent fueling.
Perhaps the man most famous for clock-like fueling consistency is Matt Carpenter, Pikes Peak legend and course-record holder at the Leadville 100. In describing his fueling approach during his epic 15:42 course record Leadville run in 2005:
“…I practiced my fuel regime about five times a week almost year-round right down to the number of sips I take per hour. Yes—18 sips an hour is what I need to stay hydrated. More if it is hot, less if it is cool. I get those 18 sips by taking 3 sips every 10 minutes. Further, I dump Carb-BOOM energy gel and Gatorade Endurance Formula right into my bottle or CamelBak so that I get about 50 calories every 10 minutes. My energy levels stay constant and I am never shocking my system like what would happen if I ran an hour or more and tried to take in the same number of calories at one time.”
Indeed, it is this consistency–and acuity of precise need–that kept Carpenter’s blood sugar at stone-cold steady levels.
Tip: Have a precise fuel plan and stick to it.
Then, have a back-up plan in case things go awry. For example, eating one item per aid station may be effective, or downing a cup of soda at each. However, be aware of variation of distance and time between stations, especially if your pace drops significantly. Using a watch timer to beep at time intervals is an effective way to ensure consistent fueling, regardless of aid-station placement.
Energy gels and drinks are the cornerstone of most runners’ fuel plans. Practice those products that either work for you, and/or are provided at your focus race.
Lastly, be prepared for Plan B if things go awry. GI rebellion may thwart any attempt to ingest your planned gel or drink. Be prepared to fuel with alternatives, and have them at hand.
Fuel is King. Keep it flowing at all costs!
Core Temperature: Keep Your Cool!
Second only to blood sugar, the brain maintains consistent core body temperature as a top priority.
Exercising muscles gives off enormous heat: the majority of energy produces for muscle contraction is wasted as heat. On top of that, we choose to run ultramarathon races in some of the most inhospitable conditions, blazing hot canyons and desert ovens with temperatures frequently exceeding triple-digits Fahrenheit. Meanwhile, our body systems have tight ranges of allowable temperatures. Outside of which, these systems will fail.
Body temperature must be regulated. If unchecked, the Central Governor will terminate exercise to protect the brain and other tissues from cooking.
Tip: Douse and ice; and slow down!
One of the popular notions Noakes strikes down in Waterlogged is the idea that hydration controls core temperature. It does not. Indeed, hydration is required for consistent sweat; however, research concludes that ingestion of copious amounts of cold fluid does not lower core body temperature. Cold water is absorbed faster, yet does not provide any cooling benefit.
The best place for that cold water is outside the body.
Cool the body by keeping it consistently wet. If racing in hot conditions, douse at every opportunity. Cold water on the skin is effective at lowering surface temperature. Another effective approach is using ice on the head and neck. As an argument for the existence of the Central Governor, cooling the head and neck–while not significantly cooling the core body temperature–cools the blood closest to the brain, in effect tricking the Governor into thinking it is cooler than it actually is.
Outside of dousing and icing, the only other means of controlling core temperature is to slow down. Run slower in areas and times of day with highest heat; conversely, run faster in shaded areas and cooler parts of the day.
As with heart rate and blood sugar, failing to heed the mounting cues of heat stress may result in a forceful and abrupt Central Governor response to cease running.
Muscle Integrity: Preserve Those Quads!
Perhaps the most important and most difficult to control factor in Central Governor management is muscle integrity. The brain monitors muscle integrity through a variety of systems, including blood chemistry and neuromuscular factors. When the brain determines that the skeletal muscle is at risk of severe damage, it will deactivate that muscle.
But sadly, unlike every other factor thus far noted, muscle damage is irreversible on race day. Game over. Once significant muscle damage has occurred and the Central Governor takes action, there are only two options: quit, or continue and invariably incur further damage, and generally have a miserable time. But one thing is certain: you will slow down, and considerably. There is no arguing with neurological deactivation of muscle. It happens for your own protection.
Indeed, one theory about why acute renal failure occurs is that acute muscle damage is occurring, yet runners ignore the strong Central Governor messages to stop. They continue to run, and continue to accumulate destroyed muscle cell debris in the blood stream, which collects in the kidneys. This, indeed, is the reason why races such was Western States test for blood values such as creatine phosphokinase (CPK), a muscle enzyme that appears in the blood when muscle cells are destroyed.
That said, the only way to avoid muscle-related Governor shutdown is self-preservation!
Tip: Run sustainably and be efficient!
There is a belief that downhill sections of hilly ultramarathon races must be run fast: “Use the downhill!” While this may be true, the more accurate message should be to run them efficiently and sustainably. Simply pounding down a hill at breakneck speed only adds mechanical stress to the muscles.
Much is said about what is the best technique for downhill running. While this an area largely absent of research, I provide both a mechanism for efficient downhill running, with a biomechanical rationale.
In Relentless Forward Progress, the age-less Dave Mackey, two-time UltraRunning Runner of the Year, advises:
“Run with short strides. This will enable better landing and cushioning on bent rather than outstretched legs… over-striding accentuates forces, leading to more fatigued muscles and pounded leg joints.”
This advice is sound; landing directly beneath you limits ground-reaction forces absorbed by the legs. Mackey also recommends focusing on:
“…leaning forward… lifting my feet by driving my knees [upward], and keeping my elbows nice and wide for balance.”
Boiled down, Dave recommends:
- Trunk forward, not backward
- Shorter, compact strides
- A high knee and foot lift
- Using the arms to counter-balance leg action
All of this has the following effects:
- The trunk forward and compact strides limit braking forces.
- The high knee/foot lift and arm use recruits proximal muscles–namely the gluts–to aid in absorbing braking forces.
Mackey practicing what he preaches at Dipsea. Photo: Gary Wang
The high-knee drive also provides something perhaps most critical: dispensing of forces from the quadriceps by providing “stretching action” consistent with normal running mechanics. Without consistent knee flexion, loading stresses build in the quad muscles unremittingly. A high-knee drive dispenses those forces, and it also passes some of the load along to the gluts. Win-win!
How about a third win? A compact stride also decreases foot stress, by decreasing shearing, blister-causing forces on the plantar foot, and decreasing compressive, nail-removing forces on the toes in front of the shoes. Triple-win!
But once off the hills, that’s where the real mechanical challenge lies: staying efficient on the flats! Prolonged hill running, either up or down, can make the flat stride sloppy and inefficient.
Tip: Practice efficient, flat running when fatigued.
A compact stride is crucial in limiting leg stress. It’s also much faster. Keep your flat stride compact at all costs! The same concepts Mackey promotes in downhill running– trunk forward, short strides, high knees and feet, arm swing–are the same needed for fast and low-stress flat running.
The best way to hone your late-race flat running stride is to practice during your long runs. In a recent conversation with a runner preparing for his first Western States, he mentioned to me his heavy emphasis on vertical training. My response was, “Have you prepared to run fast on the flat after the Canyons?”
An effective way to train that flat, efficient stride is to incorporate a section of flat road or trail at the end of a long, heavy-vertical trail run. Hammer your hills, then get on the flats and commit to fast, flat running: trunk forward, compact strides, ample hips, and arms!
An efficient, flat running strike will ensure a fast pace, low leg stress, and keep muscles firing.
Keeping the Governor at Bay
Taking all this into consideration, Noakes boils down this concept of the Central Governor into a succinct statement:
“Fatigue is merely an emotional expression of the subjective symptoms that develop as these subconscious controls wage a fierce battle with the conscious mind to ensure that the conscious ultimately submits to the superior will of the subconscious.”
Indeed, each race is a battle within ourselves. But the best way to win that battle–ensuring peak performance and physical well-being–is to satisfy the needs of the Governor to the best of your ability as long as you can. Then, only when you can “smell the barn,” should you ignore the Governor, shut off your brain, and get to the finish line!
Good luck!
Bibliography
- Explain Pain, Butler & Moseley. Orthopedic Physical Therapy Products; 1st Ed. (2003)
- Lore of Running, Noakes. Human Kinetics; 4th Ed. (2001)
- Waterlogged, Noakes. Human Kinetics; 1st Ed (2012)
- Relentless Forward Progress, Powell. Breakaway Books; 1st Ed. (2011)
- UltraRunning Magazine. (September, 2001)
- Matt Carpenter blog. https://www.skyrunner.com/story/2005lt100.htm
