Before the systemic deconstruction begins, I will start with an explanation – oh, and btw, I have zero disapproval for anyone who is a self-proclaimed VO2max worshipper. I only ask that you approach my argument with an open mind, and if you do, you might learn something that will totally change your current training paradigm. Afterall, VO2max is quite a simple concept, really, that shouldn’t be overcomplicated.

VO2 “proper” is a variable that represents the “volume of oxygen (in liters or millileters) consumed over a period of time” at a specific intensity of exercise, whether that be measured by heart rate (HR) or wattage (W). As exercise intensity increases, VO2 increases in a proportional fashion. Once the body’s ability to consume a steadily increasing amount of oxygen has peaked, you now have VO2max. This point, historically, was thought to be a direct indication of what the body was capable of doing from an aerobic standpoint and served as a rev-limiter of sorts during highly intense exercise. We now know this to be otherwise…

(Property of Sigma Human Performance 2011. Stone, B. Callaway, J.)

SO, taking a pragmatic approach to discover (I use that word for a reason) what effects a change in VO2max would automatically mean that you understand what limits VO2max and/or what factors must be in place in order to achieve a higher VO2max.

Here’s where it starts getting interesting. See, oxygen delivery and consumption (in tandem) are the real constituents of VO2 and are solely responsible for the way it increases in response to a steadily increasing energy demand. Oxygen delivery is a complex series of exchanges which, at the cellular level, terminates in the formation of water, CO2, and most importantly, energy. It should be well-known to you that blood cells (RBC) serve as the primary vehicles that shuttle oxygen from the atmosphere down to the working muscles via a network of blood vessels. Once at the muscle, another transporter, myoglobin, accepts oxygen from RBCs and transports it into the cell where small organelles called “mitochondria” use it to make energy. Obviously the minutia of that little process is infinitely more complex, but you get the point. Basically, without this process, you have zero delivery of oxygen. If you have zero oxygen delivery, then you have a non-existent VO2max. So, rational thought would then dictate your next move- investigate a training structure that first increases the abundance of this machinery in your circulatory system/muscle tissue and then apply the precise stimulus in order to maximize it’s efficiency and function- this is how you increase your VO2max. More on this later…

So, then to the point, why is VO2max such a lousy way of determining a specific training adaptation? Simply put, your true VO2max doesn’t exist. It’s a hypothetical construct that can only be elucidated in relation to your high intensity. Of course if you wanted to argue, you could point me back to the graph I gave you just prior to making this argument where its easy to see that VO2 clearly peaks and then starts a short decent until the test is terminated. You could easily say that the highest point along the red line was the true VO2max, and you would be correct… kind of. I would then ask you a very simple question: “What makes that line reach a maximal point? Why, then, doesn’t it continue up forever?” The answer is this: That little line is simple a proxy, a representation, if you will, of the muscles’ ability to continue contracting and harvesting oxygen from the blood in proportion to exercise intensity despite a reduction in central drive (from the brain).

If you have a quick read of one of our recent and more smugly-titled blog entries, “The Importance of Breathing” you’ll recall that the muscles’ ability to continue contracting is a direct result of receiving neurological stimulation from the central nervous system (e.g brain). When exercising at high intensities, lactic acid clearance is the limiting factor for athletes operating near VO2max and serves as the metabolic governor to protect the vital tissues of the body. When the brain detects the threat of an acidic onslaught, it reacts by reducing the muscle’s ability to contract and thus keeping it from further contributing to the already overwhelming pool of lactic acid. This not only spares the brain permanent damage, as well as other vital tissues, it systematically limits your muscle’s continued harvest of oxygen from the blood, THUS peaking VO2. Now, what would have happened if your body’s high intensity defense mechanisms (e.g. the biochemical equipment that makes you more resilient to low intra-vascular pHs) were a little stronger? The answer: You would be able to continue buffering lactic acid, thus keeping the brain happy and sending signals to the muscle to continue contracting. This process would allow you to continue consuming oxygen even at a much higher energy demand and would manifest in a higher VO2max.

The question I as you next would be this: “Does then, VO2max have anything to do with your body’s overall ability to consume oxygen?” Well, yes and no. First of all, having a higher VO2max is impressive and does indicate that you are equipped with all the right machinery to consume oxygen. However, if your high intensity tolerance were better, you would be able to continue exercising at a higher level and thus producing a higher VO2max. It works a bit like the governor on a high-performance sports car. A Porche’ 911 Turbo is rated at 194mph, but if you were to govern the engine where only a small proportion of its power is realized, the top speed will only be theoretical not actual, just like VO2max. See, the only way to determine your true VO2max would require extraction of a small chunk of your muscle, called a muscle biopsy (which is just about as pleasant as slamming your fingers in a sliding glass door) and literally calculating the oxygen consuming capacity of the mitochondrial mass found within. This process is nearly as impossible as it is, well, impossible. So, when you participate in a “VO2max” test, and your peak VO2 is determined, it is only a theoretical value subjugated upon your current (and I say “current for a reason) abilities to regulate your blood acid chemistry. Because this ability is very easily influenced by exposure to high intensity exercise as well as only a few days of complete rest, your tolerance to high intensity exercise can very by as much as 12% in a few weeks – so will your VO2max.

Because your tolerance to high intensity is directly proportional to muscle activation and continued oxygen consumption, your VO2max is a PRODUCT of high intensity tolerance rather than an indicator of it.

Now, it is important to state in order to be scientific, the laboratory measurements that elucidate VO2max, while theoretical in nature, are still the best thing we have to determine overall oxygen consumption and aerobic response to training. But, basing your entire training season around VO2max or using it as anything other than a simple metric in conjunction with important metabolic markers such as MEP (metabolic equivalent point), anaerobic threshold, and ventilatory threshold, is a horrible move. There is a much better and more efficient way to gauge the effectiveness of your training. Anaerobic Threshold (AT) remains to be the most influential limiter of endurance performance. Because continual lactic acid buildup will result in an eventual deactivation of muscle tissue via the central nervous system and pathways mentioned just above, delaying the onset of lactic acid accumulation is the single most advantageous and all-inclusive approach to training an endurance athlete can adopt.

In closing, while VO2max is definitely a strong indicator of overall aerobic fitness, and we have known this for quite some time, it, like all other performance metrics, has limitations. The point of all this quite simple. It is critical that athletes pay specific attention to the key metabolic markers that are directly linked to an athlete’s fuel economy rather than VO2max alone. Determining proper training intensities using anaerobic threshold, metabolic equivalent point, and maximal fat oxidation rates (ALL of which can be determined via the same channels as VO2max), allows for a much more advantageous strategy in improving overall aerobic response making you a much better, more efficient athlete. These true indicators of fitness, when used in concert, solidify the foundation of what truly establishes the framework of what makes you a successful endurance athlete.

While the following cliché is quite overplayed, it is still undeniably true: Imagine owning a Farrari 599, putting regular unleaded in the tank, then being disappointed when the car fails to perform. How could you then fault the car for being too heavy, too wide, or simply not as high-performance as you had originally been told? You would first give the car the highest grade of fuel possible and then make your determinations regarding its abilities. Why then, do we as athletes fail to provide our bodies the most scientifically proven fuels and then fault it when it fails to impress us or has an adverse reaction? The truth is this: Many athletes, even professionals, have little understanding of what is necessary, nutritionally, in order to keep the body running at maximum.

The answer? Simplicity. If you’ve every heard of “Occam’s Razor”, you know it is a proverb that asserts that the most simplistic answer is probably the most correct. So to arrive at the simplest solution one must understand a little about the body and what it requires while performing at race intensities before a nutritional strategy can be implemented. First of all, the single most important molecule in the human body is carbohydrate (CHO). It is the sole source of energy for the brain, powers red blood cells, and packs one hell of a punch as a high performance fuel for muscular contraction. It should come as no surprise then that athletes need copious amounts of carbohydrate when participating in their respective sports. The only question is this: How do you get it and in what forms? Unfortunately, the endurance market is awash with multitudes of different CHO replacement products asserting more of a positive effect on the body than their competitors. However, there are only so many ways to bundle the exact same substance and sell it with ridiculous claims for enhanced performance. So, here’s a guide for making your selection before I give you my recommendation… I know it’s a bit like putting the milk and bread at the back of a grocery store, but trust me, it’ll be worth your time to read what comes next instead of skipping directly to the epilogue.

First of all, when you scan the nutrition panel of any CHO replacement product you’ll notice right away that “sugars” or “glucose” is always a sub-heading underneath the main heading “Total Carbohydrates”. This causes mass confusion in the endurance population so pay particular attention to this next part: If you subtract “glucose” or “sugars” (depending on the way it’s labeled) from total carbohydrates, you’ll have the total amount of maltodextrin or glucose polymers in the product and NOT the amount of glucose itself. Maltodextrin, a common ingredient in CHO replacement products, is a one type of glucose polymer, which is basically a chain of glucose molecules (poly = many) biochemically bonded to each other. The reason nutritional companies use maltodextrin and other glucose polymers is because 1) maltodextrin does not participate in the osmotic balance (amount of small particles dissolved in a solution) in the stomach 2) it has the ability to be broken down slowly (you may have heard the term “slow-release carbs”), and 3) it has a relatively long shelf life with few necessary preservatives. However, because of its chain-like form, maltodextrin is biochemically inert as an energy producer. In other words, it has to be broken down into individual glucose molecules before it can participate in the formation of useful energy. Because this process takes considerable time and occurs only under the right conditions, maltodextrin will sometimes languish in the digestive tract while being biochemically whittled down into much smaller more manageable components. Due to the polarity of maltodextrin, it attracts vast amounts of water to gather around it, which can quickly precipitate bloating, severe gastrointestinal distress, even diarrhea and/or vomiting. So why use maltodextrin? Because, in products that are single-use such as those found in tear-off foil packages, where quite a large amount of carbohydrate must be injected into the stomach at once, maltodextrin is actually a good choice. If the dose were straight glucose, the exact same situation would occur (bloating, GI distress, nausea, etc.), due to the fact that glucose would increase the osmolarity of the stomach and force it to retain water. To circumvent this issue, maltodextrin is used because, at low exercise intensities (~70%VO2max) when there is plenty of blood flow to digestive tract, it can alone satisfy the need for CHO to keep the brain and muscles working at a suitable rate with minimal disturbance to the delicate balance of the stomach.

While exercising at or above 75%VO2max, the need for carbohydrate can be met by a modest amount (~40g/hr) of CHO. But as intensities begin to rise, the muscles, brain, and internal organs require more CHO (~60g/hr) in order to continue functioning under an increased energy demand. Unfortunately due to a shunting of blood away from the digestive tract at these intensities (~80% VO2max), precious little exogenous CHO (CHO coming from foods and drinks) actually makes it into circulation. This problem is compounded when maltodextrin is used as the primary CHO source. Due to its bulky nature and digestive complexity, it actually forces the muscles to become more dependent on finite stores of muscle glycogen, which, when empty, spell a catastrophic and immediate decline in performance.

So, how does one safeguard themselves from glycogen depletion and the potential side effects of reduced rates of gastric emptying when using maltodextrin in concert with high intensity exercise? It’s quite simple, really. Don’t use maltodextrin. Use glucose instead.

The use of glucose-based products will have a variety of advantages at high intensities. First of all, glucose can more easily perfuse through the walls of the small intestine, enter directly into the vascular stream, and doesn’t it require any cellular remodeling (as does maltodextrin) before it is absorbed. The only catch with glucose intake during high intensity exercise is this- it is an ABSOLUTE necessity that it be taken in very small doses. Where most energy gels can be taken on a more sporadic basis (and in larger volumes due to the stability of maltodextrin), glucose should be ingested in very small amounts via more frequent feedings. Ingesting glucose in small amounts will insure that the delicate balance of fluid osmolarity inside the stomach is preserved so as to prevent any gastrointenstinal distress. It is here that most athletes make gross miscalculations in supplementing glucose over maltodextrin. Athletes commonly assume that the glucose supplementation can occur on the same frequency and in the same dosage as maltodextrin based products, which can commonly result in severe gastrointestinal distress due to the inherent properties of glucose itself. If glucose was administered in smaller doses and on a much more frequent basis, these problems would almost certainly be non-existent.

So, what sources of glucose-based products are most advantageous? There are several with purported benefits, like electrolytes, B-vitamins, and stimulants all designed to give you an advantage over their competitors. However, according to basic structure and consistency, they are all second to one source that is literally the most perfect form of glucose supplementation currently available to endurance athletes. Honey. Honey is a form of CHO storage that is not only composed of glucose, but also of fructose (fruit sugar and the sweetest naturally occurring CHO in existence). Not only can your body use glucose to create energy, but it can also use fructose via a secondary transport enzyme in the small intestine. In strictly glucose containing supplements, glucose absorption in the small intestine can only occur at the rate of 1g glucose/min. With the additional influx of fructose at the rate of 0.25-0.5g/min, your total carbohydrate intake can be increased by nearly 50% when using fructose and glucose-containing supplements such as honey.

The effectiveness of honey is, of course, dependent upon how it’s used. If small doses are taken every 10mins (small sips instead of large doses every 30mins as is the case with maltodextrin-based products), honey has a higher propensity to elevate blood-glucose levels, increase neurological output from the brain (increasing contraction strength and velocity), and will decrease the dependence upon internal carbohydrate stores. These effects are most notable at high intensities where digestive rates are slowed due to a shunting of blood away from the GI tract and to the working muscles. The best way we have found to supplement honey is through the use of the common gel flask containing a mixture of honey and water. The water acts to decrease the natural viscosity of honey and allows the user to more easily track the volumes of each dose. One tablespoon of honey contains 17g of carbohydrates which means that a gel flask with 5-6 tablespoons of honey will meet the CHO needs of athletes exercising at 80% VO2max for approximately 2hrs.

The issue of CHO supplementation is complex but will become much less confusing if you remember a few key points. Maltodextrin is relatively stability inside the stomach, will not influence stomach osmolarity, and can be taken in large doses. Thus, it is a perfect low-intensity exogenous CHO source. As exercise intensities increase and the body becomes limited in its digestive capabilities, the combination of simple glucose and fructose based supplements are perfect high-intensity solutions. As long as the delivery method of each one of these CHO replacement strategies is understood and respected, maltodextrin and glucose/fructose-based supplements can actually be used as perfect complements to each other as intensities constantly ebb and flow during a race. Due to the perfect combination of fructose and glucose, honey provides simplicity, a low economic impact, and the ability to meticulously control the rate of CHO intake when it matters most. Above all, honey’s ability to elevate blood glucose levels allows the brain to continue performing without the threat of malnutrition. All of these factors combined work to enhance the efficiency of “the” complex biochemical matrix that allows you to continue performing at your peak.

At rest, respiratory rates (RR) are between 8 and 12 breaths per minute (bpm). However, during exercise, it is common to see RR at or slightly above 70 bpm in highly trained athletes. While it is safe to assume that the demand for oxygen increases with exercise intensity, as evidenced by VO2max testing, it is not so clear why RR are so varied among the endurance population. What is clear is that athletes with higher VO2maxs (>55ml/kg/min) almost always exhibit maximal RRs at or above 60 bpm. One could assume that athletes with higher VO2maxs require faster RRs simply to continue the flow of oxygen that is so critical to aerobic exercise. However, that is not the case. What is of greater importance and is often overlooked is the amount of CO2 produced as a resultant byproduct of BOTH aerobic and anaerobic respiration- which commonly operate in tandem when energy demand is high. Unfortunately, most athletes and coaches are so concerned with increasing the adaptive mechanisms that assist in oxygen delivery and consumption; they pay precious little attention to the overwhelming buildup of CO2 within the body. Examine the following equation:

H+ (acid) + HCO3-  –> H2CO3 –> H2O + CO2 (gas)

Notice that the symbol “H+” denotes the presence of acid within the blood. HCO3- represents the bicarbonate buffers that exist within the blood to stabilize blood pH. During rest, these two molecules exist in a delicate balance that holds the blood’s pH at 7.1. For those of you who remember your 9th grade chemistry, you’ll remember that a pH of 7.0 is neutral, a pH of 1.0 is extremely acidic (such as stomach acid), and a pH of 14 is incredibly alkaline (such as lime). Therefore, the blood’s pH remains very close to neutral, mostly to protect the delicate tissues of the brain from any acidic damage. Now, during high intensity exercise (above the anaerobic threshold), lactic acid produced in the muscle cell is immediately escorted away from pH-sensitive contracting muscle tissue and ushered right into the blood. This process is analogous to you tossing your accumulating garbage over the fence into your neighbor’s yard. However, the blood carries within it bicarbonate buffers (HCO3) that function to eliminate this biochemical waste before it accumulates. Notice the above equation where acid (H+) bonds to the buffer (HCO3-) to form a neutral molecule (H2CO3), which is harmless within the body. This molecule then travels back to the heart via venous return and is then sent to the lungs where it is converted to CO2 (gas) and water vapor. When you exhale, the newly created CO2 from acid buffering is expelled into the atmosphere via your expired breath therefore preserving blood’s neutral pH.

Even when exercise intensities increase and blood acid levels become elevated, this process can serve to safeguard the brain and internal organs from the acidic onslaught brought about by muscle tissue continually dumping acid into the blood- but only under one condition: You must continue exhaling CO2 at a rate that is proportional to lactic acid buildup.

In chemistry, many reactions, like the one above, can in actuality, run in reverse if the products (CO2 + H2O) become so abundant that they outnumber the reactants (H+ + HCO3-) Meaning, if CO2 isn’t expelled at the same rate that H+ is produced, the reaction will begin flowing in reverse thus producing acid rather than eradicating it. This is MAJOR biochemical event inside the body. At this point, RRs, CO2 expiration, and perceived effort increase exponentially as the brain begins to panic in response to the steadily decreasing pH of the blood. Because the brain is in direct contact with both the blood and the contracting muscle tissue, any change in pH due to the blood’s inability to properly dispose of CO2 will increase the level of acid to which the brain is exposed. This has profound consequences that can result in death IF the pH of the blood drops to 6.9 or below. Now, luckily humans are equipped with certain shut-off mechanisms that prevent such a circumstance from ever happening. However horses and dogs are not as lucky. If you’ve ever heard of a hound so motivated after it’s quarry that it “ran itself into the ground”, believe it. It’s true. The accumulation of lactic acid due to extreme sustained exercise intensities created a condition known as “metabolic acidosis”, which can be fatal. Fortunately for us, the brain, when threatened with a massive exposure to blood-acid, has an innate understanding that if neural drive to the muscle is reduced, muscle contraction occurs on a more sporadic basis and less forceful basis thus stemming the flow of acid into the already overwhelmed blood. This “central fatigue hypothesis” prevents any damage to the brain, internal organs, or muscle. However, it does not help you, as an athlete, as your performance now comes to a very punctuated end.

Now, back to the original argument, CO2 expiration. Most untrained athletes, at max, only take around 45 bpm, which is only 2/3 that of elite endurance athletes. Because of this reduced CO2 output, the ability of the acid-buffering reaction to keep running forward and continuing its important role is highly compromised. If more CO2 was expelled via quick, rapid, forceful exhalations, more H+ could be removed from the circulated blood supply before the brain senses a drop in blood-pH thus initiating central fatigue.

This is in a direct contradiction to current paradigm that deep breathing will aid in oxygen transfer and will prolong an aerobic status in the working muscles. While more diaphragmatic breaths do have an effect, its basis is much more psychological than physiological. Recent research has shown that when breathing rates are below 30-32 bpm, the athlete’s perceived exertion is actually lower than when breathing rates are above 35 bpm even when exercise intensities are the same. Thus most athletes find it more comfortable to voluntarily depress RRs even at high intensities where CO2 expiration will act as the primary determining factor in an athlete’s anaerobic tolerance- not VO2max. This can be likened to putting a governor at 90mph on a sports car whose top speed is rated over 200. Due to the electrical inhibition coming from the governor, the car will never fully realize its ability to operate close to its estimated maximum. This is the exact mechanism by which your brain systematically limits muscles from contracting and further contributing to the already overwhelming level of acid in the blood.

Lactic acid clearance is the limiting factor for athletes operating near VO2max and serves as the metabolic governor to protect the vital tissues of the body. It is critical not to limit respiration rates when the energy demand is high simply due to the overwhelming effects of central fatigue. It is vital to your performance as an athlete to practice frequent forceful exhalations when you train at or near ~85-90% VO2max. This will assist your body in removing the acidic by-products of anaerobic respiration, stabilize blood-pH, and will allow your brain to continue providing neural input to your working muscles. These effects will allow you to increase your anaerobic tolerance, cardiovascular output, and afford you a faster recovery from sustained high-intensity endurance exercise.

• Most athletes take only 45 (bpm = breaths per minute) at 80% VO2max and above
• Elite athletes have been shown to take 65 bpm at or near VO2max
• Lower respiratory rates (RR) can severly limit your ability to remove CO2 from your blood and DO NOT increase oxygenation of blood as could be expected
• CO2 is directly linked to the level of acid in your blood
• Failure to remove CO2 via exhalation will result in an inability to remove lactic acid in the blood
• The brain is very sensitive to changes in blood pH
• As acid builds up in blood due to a low RR at very high intensities, the brain reduces the level of stimulation to the muscles = “Central Fatigue”
• As the brain reduces central drive to the muscles, your perceived exertion increase exponentially
• This is done to prevent the muscles from continually producing more and more lactic acid which could damage the sensitive tissues in the brain and internal organs
• Once you stop, your blood pH begins to return to normal and you can eventually continue the exercise
• To keep this from happening, make sure you practice rapid, forceful exhalations when exercising at high intensities

By Spencer Watson

Benjamin Stone doesn’t quite know what to call himself. At the most essential level, he works with people engaged in athletic activity, motivating them to do better. So you might say he’s a coach.

But he’s also a scientist, one who can analyze the byproducts of metabolic systems to figure out how efficiently a person’s body is working and how that efficiency could be improved to meet a specific goal.

“I call myself a physiologist. That can sound fairly pretentious, but it’s a better description than just ‘coach,’” said Stone. “Yet you can have all the science in the world, but if they’re not motivated, all that training is kinda worthless. You gotta get in their heads.”

That he said this amidst a west Little Rock laboratory filled with gadgets and gizmos intended to gauge what, exactly, a person’s body is doing while it’s working, complete with an entire wall covered in chalkboard paint and graphs and charts of things like fatty acid oxidation rates, only drives home the point.

You could say the lab is the heart of his operation, called Sigma Human Performance, but, like the coach label, it’s not quite right. There’s another lab recently opened in Arizona. And, frankly, in this modern age, Stone’s office is technically wherever his phone is. Thanks to Cloud-like information flow, the data he needs to do his work can be accessed from anywhere.

You might think, with all this accessibility and technology that the humans Sigma helps perform are the highest tier of athletes, the professionals who make their living beating out the best in the world at what they do. That wouldn’t be quite right either.

“They’re people you see every day. Not high performance athletes, but high performance people,” said Stone. “They’re not professional athletes, and they have no intention of ever being one.”

That’s not how things started, and that’s really what was intended. But that’s the way it is, like so much else for Stone.

A native of northeast Arkansas, the 28-year-old grew up in Vilonia, where he said the choices of pastimes were to be a rodeo cowboy or blow things up. He chose the latter, and it meant a childhood not free of some bouts of trouble. But it was never trouble that interfered with school, as Stone moved ahead in grades and ended up graduating at age 16. It made for some … interesting challenges.

“I’d tried out for football, but they said, ‘This kid can kick, but if he got hit, he’s going to die,’” Stone laughed. That led him to cross country, which turned out to be significant later in life when he turned to endurance training.

Meanwhile, his academic interests were piqued by biology, thanks to a teacher who years later would end up embroiled in a scandal with a student. Though not condoning the teacher’s later actions, Stone said he was still a defining influence in his life.

“If not for him, I don’t know where I’d be right now,” he said.

Where his life ended up going was to the University of Central Arkansas, where he found himself always younger than classmates, including the senior he roomed with his first year who introduced him to mountain biking.

“It was kind of a handicap, to be honest,” said Stone of always being younger than his peers, including being mistaken for his fraternity brothers’ little brother. “I was always awkward around women and, of course, I had zero athletic ability. I was really good at being a nerd.”

Maybe, but smarts set him on a quick course through college. Graduating before he could legally drink liquor, he ended up opting for post-graduate work at Exeter College, Oxford, where he earned the equivalent of a doctorate degree in human physiology by age 23.

Then came the inevitable question for those leaving university: Now what?

Even then he thought about coaching — strictly coaching. But it didn’t go over well with the parents.

“They basically said I’d spent a quarter million dollars on education to start at what, $14,000 a year? Well done.”

So instead he returned to UCA, this time to teach. And he loved it. Still does. But coming directly from the British system, he proved to be “a bad fit for all the right reasons.” The atmosphere of American academia, he said, just didn’t fit the open forum discussion style he’d fallen in love with at Oxford.

It also happened that around that time a friend had approached him about developing a training element to an existing retail cycling business. It was researched and written and floated amongst several affluent members of the global cycling community, and everyone seemed stoked about it.

“We’d gotten this incredibly robust plan together … we figured there was no way they could say no. So I’d already quit my job. I was 26 at the time and full of piss and vinegar.”

Then the plan was rejected in favor of staying retail-oriented.

“I was freaked,” said Stone. “I didn’t have anywhere else to go.”

Finally, the partner in the plan, still convinced of its success, suggested Stone try to launch it on his own. He went to the people it had originally been prepared for and, with their permission, tweaked it to fit an independent business model and set out, cashing in his teacher retirement for start-up funds. Sigma was born.

“Things just happened freakishly easy,” said Stone of starting out. “Whenever I needed to make a decision, the path just laid down in front of me, and I would network with the right people at the right time.”

Ultimately where that path has led is to a point where all the interest points of Stone’s life — the teaching and the training and the science — all meet. His staff includes not just himself and other coaches, but nutritionists and a consulting biostatistician as well.

“When you do the right thing, things tend to work out for you in a certain format. And I feel like I’m doing the right thing.”

Primarily that’s helping people reach their goals and using emerging science and technology to do it, not for reasons of vanity or self-importance, but for simple improvements in quality of life. Maybe the goal is a 100-mile bike ride. Maybe it’s only shedding weight — not to look better (though they will) but to avoid a heart attack by age 50. Either way, it’s not the work Stone thought he’d do, but it’s what he’s found most rewarding.

“I educate people who are motivated by the right reasons to undertake severe change in their health and lifestyle. And aesthetics just isn’t it. That’s not it at all.”

First off all, and without getting into too much unnecessary detail, the basic crux of the argument surrounding endurance training is the availability of oxygen as exercise intensities increase. Understanding how to maximize an athlete’s oxygen consuming (notice I did NOT say oxygen “carrying”) capacity is really the Holy Grail of endurance training. With an increase in oxygen consumption, you see cascades of positive events which all serve to increase the fuel economy of an athlete. Utilization of fats, in lieu of carbohydrate (CHO) is one of the most advantageous effects of an increase in oxygen consumption because it allows the athlete to successfully limit the amount of endogenous carbohydrate (muscle glycogen) used during low to moderate intensity exercise. Because fats need nearly 30% more oxygen to be converted into energy, only athletes who possess the proper cellular machinery to consume suitable amounts of oxygen to power fat oxidation see the benefits therein. Of course, this ability is trainable but ONLY if stress is applied to the zones that will elicit the greatest increase in aerobic capacity. This zone is commonly referenced as the “Aerobic Target”. The AeT, for short, is the intensity zone in which the athlete shows the greatest dependence on fatty acids during exercise. Because the individual metabolisms of endurance athletes are inescapably different, any basic standardized formula used to predict this range based on a age-estimated max heart rate is a complete waste of time- and can often be detrimental by providing justification to train at intensities that are much to great to elicit an aerobic response. The only method of determining this zone is by use of devices that measure and compare levels of carbon dioxide and oxygen within expired breaths (i.e. participation in a Vo2max test).

Secondly, and in the same vane as increasing fat oxidation via training according to one’s own metabolism, is the elucidation of the anaerobic threshold (AT). There have been many field tests proposed and many attempts at isolating this metric without expiratory data, but research has clearly stated that because of the uniquity of each endurance athlete, without capturing expelled carbon dioxide, elucidation of AT becomes a metabolic snipe hunt. Before continuing, in would be prudent to further clarify what AT is as there is some degree of confusion about the point at which the AT is reached and the results of such action. When an athlete increases his/her intensity past the point where sufficient oxygen is present to continue the breakdown of CHO to meet the necessary energy demand, the muscles begin converting CHO to energy without the presence of oxygen. This point, and resulting metabolic switch, is called the anaerobic threshold (or lactate threshold). Most athletes fear the point at which they go anaerobic due to the resulting buildup of lactic acid. While this is the case, and something to heed, the effects of long-term (low-level) anaerobic respiration, such as that which is encountered in marathons and long-course triathlon, are much more global. When anaerobic, muscles are producing energy at an accelerated rate thus satisfying the energy demand, however each molecule of CHO produces 18x less energy via anaerobic metabolism when compared to aerobic metabolism. Thus it is easy to see from an energy accounting standpoint, that long-term exposure to exercise intensities at and above AT puts a substantial strain on muscle glycogen levels. Thus, knowing exactly where this metabolic change takes place is essential to rationing and supplementation of carbohydrates if exposure to intensities in excess of AT is necessary for extended periods.

While understanding of this biochemical ballet is crucial to training efficacy, the real advantage of Vo2max testing becomes evident when you begin to globally examine what limits your overall physiology in your endurance pursuits. Athletes who make the common mistake of engaging in training structures that are much to intense are subject to reduced aerobic efficiencies, CHO dependence, exercise induced hypoglycemia, and low Vo2maxs. It is always a shocking discovery for any athlete to be confronted with the fact that their training has actually led to a systematic weakening of their aerobic metabolism. In other words, because they were unaware that the majority of their training was done in excess of their AT, there has been little no stimuli or justification for the body to increase it’s oxygen consuming abilities. Therefore, to counteract this, the athlete would need to spend more time in zones beneath the AT so that proper stress is placed on the aerobic system to become stronger and more efficient. Without identification of this issue, and due to the fact that the athlete was completely unaware that the AT was constantly reached, there would be little improvement in overall aerobic proficiency. Additionally, because the data from a Vo2max test will provide a detailed outline of which macromolecule (fat or CHO) is being used most readily and to what extent, it is possible to determine, to the calorie, how many grams of CHO are necessary to continue fueling at a given intensity as to avoid complete muscle glycogen deficit.

As should now be clear, the uses of Vo2max/metabolic data reach far beyond exposition of just Vo2max alone. They provide the framework for isolating and improving upon any metabolic limitation whether at low or high intensity. Secondly, Vo2max/metabolic data allows for a non-biased, individual assessment of training and diet effectiveness. Therefore it is possible to determine if further attention to your limitations is necessary before moving into a different period of training instead of blindly adhering to traditional season-long non-individualized periodization plans.

On to business.Recently, I was confronted by an article in Runner’s World Magazine where a coach was telling a client to estimate her anaerobic threshold (AT) by running what basically amounted to a 5k and averaging her heart rate (HR) for the final 10mins of the run. I sat back, pondered for a second, and began a hateful letter to the editor of Runner’s World about why they would allow something so blatantly false to appear between the bindings of one of the most widely accepted periodicals in endurance sport. From a metabolic standpoint, that advice could be likened to a nutritionist informing runners that the best way to dietetically prepare for their “A” priority race is to shotgun a gallon of whole milk 15mins prior to the start. However, in my opinion, the above strategy recommended by Runner’s World would in some cases be much more severe because this was their basis for determining season-long training zones.

So, let me explain why this method for finding AT is so limiting. First of all, anaerobic threshold is the point at which your muscles are forced to begin expediently producing energy in light of a continually diminishing supply of oxygen. Here’s something you may not have known. You’ve probably heard for quite sometime that oxygen is critical to exercise, but to truly understand why, think of an engine in a car. The engine consumes fuel and as a result, energy is produced. But, the byproduct of this catalyzation is heat and lots of it, which if left unchecked will slowly erode at the engine’s performance over a given period of time if not stop it altogether. To counteract this problem, you have a radiator circulating water around the engine to absorb the byproduct heat and keep the engine running at its maximal efficiency. This is the EXACT job duty of oxygen. When you produce energy aerobically (with oxygen), your muscles begin a massive cascade of cellular events which eventually terminates in the production of energy (in the form of adenosine tri-phosphate [ATP]). However, there are some byproducts that form along the way which will decrease the efficiency of the muscles if, just like the car engine’s heat, they are left unchecked. This byproduct in the “aerobic form” is very similar to the byproduct in the anaerobic form, which you have probably seen represented as a “H+” in numerous references without even knowing it. Think of the term “pH”. pH is a measure of acidity. The higher the acid content (H+), the higher the acidity. The lower the (H+) content, the lower the acidity. Remember this in just a second… Now, on to the point. Acid, as you know is corrosive, it interferes with the biochemical processes that produce energy in muscles, and causes the pain that you feel during hard efforts. What you may not know is that when you exercise aerobically, you are STILL producing small amounts of acid even though you are exercising below your AT. The acid is a different form, yes, than the acid you produce while exercising above your AT, but the effects are STILL the same. Think of it like this. If you own a factory producing golfballs and Tiger Woods calls up and wants 30 million of them by the end of the week, your factory had better begin working at maximal capacity to fill the order with time to spare. So to maximize productivity you as the owner had better create an excellent environment in which your employees can work if you expect a higher-than normal level of production. The same situation exists in the muscles (and more specifically in the mitochondria, which serves as the vessel for the extent of this process). When exercise intensities increase, you require more energy from your muscles than you naturally would at rest. Therefore, the working conditions inside the muscle had better be optimal or their overall productivity will be compromised if not halted altogether. Because the environment is becoming increasingly acidic with time, all those little biochemical reactions critical to aerobic ATP production start becoming unhappy. Just like the workers inside your golfball factory, if the temperature starts to rise to the point it becomes uncomfortable, you had better find some ventilation- and quick. You’ve got a HUGE order to fill.

Luckily, we have a very effective helper that takes care of this issue of acidic buildup before conditions inside the muscle become intolerable. Oxygen. Oxygen, as you may not know, is incredibly good at neutralizing this situation and restoring optimal working conditions inside your muscles. Here’s why. Oxygen is one of the most incredibly negative elements on the periodic table carrying a -2 charge around with it wherever it goes. Basically, it’s looking for 2 buddies to help bear the load of the negative burden. Interestingly enough, H+, the bad guy in this situation whose population is out of control, carries a +1 charge. Now, if you kind of get where I’m headed and you carry a basic understanding of arithmetic, you’ll have noticed that oxygen is capable of picking up 2 of these H+’s thus decreasing their population, reducing the acidity inside the muscle, and making all of your workers happy by improving working conditions.

For those of you that paid attention in class back in the 6th grade, can you tell me the common name for this molecule? I’ll give a hint. The chemist’s name for it is “di-hydrogen monoxide”. Still no? How about this- Water. That’s it, basic H20. That’s oxygen’s sole responsibility – finding a suitable alternative for the increase in acid content within the muscle. Remember capillaries, red blood cells, haemoglobin, myoglobin, iron…. Yeah, all of it exists for this ONE simple purpose- to transport oxygen from the atmosphere to the muscles where it’s circulated just like the coolant in a car’s radiator to remove the byproduct of aerobic respiration.

It’s really quite extraordinary if you sit and think about exactly WHY you need oxygen. Most people, when they attempt to answer this question, trip all over themselves trying to find a suitable explanation when all they do is leave themselves, and their audience, with more questions. But the answer is simple. Oxygen isn’t fuel, and it can’t be “burned” for energy like most people think. If that were the case, there would be zero need for carbohydrates or fat. It’s sole purpose, it’s only function is to keep the delicate system of aerobic respiration in balance and running efficiently by clearing the byproduct of ATP production.

To sum up everything above, the speed of aerobic respiration is governed by the presence of oxygen, which has MAJOR implications for endurance athletes. Basically, aerobic respiration can only run as fast as the supply of oxygen is plentiful. At this point, if the demand for energy increases when the capacity of aerobic respiration is maxed out, then the body is forced to recruit anaerobic respiration to help with the energy demand. At this point, you become anaerobic, and start generating massive amounts of lactic acid. Because there is little oxygen to stem the acidic onslaught at hand, your body relies on other defensive mechanisms that I shall clarify in act II of this saga. The point is this- if you simply had more oxygen available at the point you begin needing the help of anaerobic respiration, you could have put off the onset of lactic acid buildup thus increasing your aerobic efficiency and overall aerobic power.

So, to complete this circle- Remember my anger of Runner’s World editor X who approved the so-called “anaerobic threshold” test where you run as fast as you can and then average the last 10mins of your HR? Well, here’s the problem with that. You will NEVER perceive the point at which you go anaerobic. It’s a biochemical switch that cannot be “felt”. It can only be registered by equipment sensitive enough to detect the onset of lactic acid – the tell-tale sign that you’re anaerobic. When you exercise with an increasing intensity, the only sign that we have for perceived exertion is our respiratory rate, which really serves as the “top end” of our athletic abilities. As your intensity increases, so does your respiratory rate, but very rarely is there ever a marked increase in respiratory rate when you hit and surpass your AT. Your breathing only becomes labored quite near your VO2max. Using this value as the basis for your anaerobic threshold, as Runner’s World might lead you to believe, would mean that nearly all of your sub-lactate efforts would STILL be in excess of your AT. Why is this is a huge problem? If you never exercise below your AT, where oxygen is still heavily relied-upon to keep everything running aerobically, your body never has any justification to increase your oxygen-consuming abilities. Have you ever gone to a gym and seen the typical gallon jug-carrying, cut-off camo shorts-wearing, wanna-be body builder? Their upper bodies are massive. Their lower bodies- Non-existent. Why? Well the answer is simple. Doing “bicep curls for the girls” has little effect on building their quads. Being that training upper body muscle groups occupies the lion’s share of their attention, their lower bodies simply waste away into oblivion. The same is true on a biochemical level. If you exercise at high intensities- intensities well above your AT, your body has little justification to increase any of its oxygen consuming abilities, and thus, your aerobic potential becomes analogous to a body-builder’s “chicken-leg syndrome”.

So, by employing the all-to-common AT elucidation formulas that you may have read about in your favorite workout magazine (and I’m not just picking on Runner’s World here), you’ve just dealt yourself a crushing aerobic setback. The point is this, if you don’t want to use more appropriate, more precise methods of determining AT through VO2/metabolic testing, then please make sure that when you participate in a field test, you take about 75% of whatever your “final-10min HR” turns out to be (and even this applies to only a small percentage of athletes). By doing so, you guarantee that any workout designed with aerobic adaptation in mind turns out to be precisely that, and not just another exercise in anaerobic futility.

Train wisely.

What I will do over the coming weeks is to devote a considerable amount of energy to deconstructing “lingua cycliste” and then rebuild it for you with simplicity and focus. There will be several terms I will dissect, but I am still waiting on you to provide me direction. Thus, requests would be welcomed with open virtual arms.

The first issue to which I plan on devoting attention is the concept of “BASE” Training. Of all the terms or phrases I hear being thrown around on a consistent basis (especially during the winter months) is “base” this “getting my base” that. One of the innumerable reasons I have respect for Dr. Ernesto LaChuga of Chainwheel University is due to the fact that, on our first meeting, he directly asked me if I held any favor towards “base training” (BT). I regretfully answered “No”. For the record and future recourse, I would like to say that that statement was a lie. My answer should have posed the following question to him- “To what type of base training are you referring?” I say this because the traditional sense of BT holds little validity. Let me explain.

WHAT DOES BASE TRAINING ACCOMPLISH?

As the heading implies, I will focus my attention away from what BT is and direct my efforts toward what BT should be and how it is designed to affect your aerobic physiology. Herein lies the benefit from such training- yes, I said “benefit”- implying that BT WILL indeed make a difference to you, your training, and your upcoming season.

BT itself is a misnomer with the emphasis of this fallacious phrase falling squarely on the shoulders of the word “base”. This word slash training ability to upregulate your aerobic system to accommodate a greater ability to ride at low intensities for long periods of time is the eventual aim of such training sessions. Ask anyone and they will tell you the same. However, to imply that you cannot have an elevated level of fitness without first solidifying your “base” is simply erroneous. What I am attempting to illustrate is the fact that many cyclists are incredibly successful with very little aerobic training whatsoever. They choose to focus their attention on maintaining as high of wattage or HR as possible for a designated period of time—basically hammering for as long as they can. Know someone like this? Of course you do. You yourself may have this badge pinned on your jersey and not even know it. Really, if your event lasts less than 90mins, this training strategy is actually quite advantageous and prescribed by many a physiologist. Thus, depending on the metabolic demands of your event, ignoring your “base” aerobic training is not necessarily a bad move. Cyclists who prefer criteriums, track racing, or time trials fall in this category. These events demand incredibly high, sustained bursts of power and strength, but also require a consistent metabolic resiliency. This latter point, I will address in a subsequent essay. Back to BT.

From this point, it would be a mistake to assume that you can’t have one type of fitness without the other. Instead of thinking as aerobic fitness as the “base” of the training pyramid with the top 1/3 comprising anaerobic high-intensity fitness, think of it as two pyramids separate from each other in almost every way, except for a small overlap at their foundations. For matters of simplicity, I sometimes refer to these two training adaptations (aerobic and anaerobic) as two individual companies that conduct business entirely separate from one another, but remain consolidated under a single bank account- being your performance. For a well-rounded cyclist, your elevated (to use this word in the same context as “base”) fitness is just as important if any degree of race/event success is desired. However, there is one HUGE difference between the way these two adaptations are achieved… Time frame.

When focusing on your aerobic fitness, you need to target your training to elicit an improvement in your body’s ability to transport and consume oxygen. Being that oxygen is the only currency by which your “aerobic company” conducts business, ensuring a proper handling of “currency” will certainly increase revenues. There are three major adaptations that take place inside your body as your aerobic training status improves. 1) increased mitochondrial size and population, 2) increased capillary density, and 3) increased hematocrit (RBC count).

Mitochondria, as you may know are the metabolic cellular furnaces that use oxygen to degrade fat and carbohydrates in an effort to create energy (in the form of ATP) filling the subsequent energy void. Thus any increases in size or overall number of mitochondria will upregulate oxygen consumption and ATP production. As a companion, increasing capillary density is an excellent method of perfusing more blood to the muscles that are most actively involved in exercise, thus delivering more oxygen where it is needed. And last, but certainly not least, increasing your blood’s oxygen content involves raising your number of RBCs found in circulation at one time.

These adaptations work in concert to increase your ability to exercise at moderate intensities with very little cellular stress. However, the time it takes to see any difference in these areas is considerably longer than the time it takes to improve your anaerobic (elevated) fitness. Depending on the precision of your training, it can take as long as 4 months to see any noticeable improvement in your oxygen carrying capacity (the gold standard for determining your aerobic capacity is a VO2max test). Therefore, it is vital that this type of training be initiated early enough in the season to allow for aerobic upregulation. However, once elevated, aerobic capacities require little maintenance to remain elevated. That’s why you see many endurance athletes return to their sport a year after relative inactivity only to immediately regain the level of fitness they had prior to hiatus—The obvious example is… well, nevermind…

Your elevated fitness (i.e. anaerobic capacity) is much more subject to change and tends to wax and wane like the moon depending on the phase of your training. The reason for this is the nature of the changes taking place. Aerobic adaptations, in contrast, are quite nearly structural—representing an increase in some tangible entity whether it be more blood vessels or more RBCs. Any increase in elevated anaerobic fitness is more closely associated with upregulating the speed of biochemical pathways (i.e. glycolysis, the Cori cycle, etc.) which take place on a more punctuated time table. This focus is commonly referred to as “peaking” for a race. Traditionally, the “peak” period is approximately 7 to 10 days in duration and consists of low volume, high intensity workouts. This is literally the best and only method for increasing your elevated fitness and can be completed several times throughout a race calendar. I will go into more detail on this issue as the season progresses.

Therefore, to conclude with a bit of direction, it is important that if improving your aerobic fitness is your current periodical goal, you target your workouts to match precisely the demand necessary to elicit the desired changes. Conservative training will get you very little aerobic response due to a stimulus that isn’t great enough to merit the necessary adaptations while erring on the side of intensity will get you overtrainined and mentally exhausted very quickly—not to mention focusing your attention on the wrong business… You must determine your zones, outline your volumes, and stick as closely as possible to the prescribed protocol in order to maximize your aerobic benefit. It is a metabolic balancing act that few have mastered, however, it can definitely be accomplished with an attention to detail and a concentration on your seasonal structure.

When using your max HR for zone calculation it is very important to take into consideration the time of year (proximity to key events), fitness status, and primary method of training. As you become more aerobically fit, your max HR increases due to the increased oxygen demand placed on your cardiovascular system via mitochondrial oxygen consumption (in the muscle). This can be seen during near-max efforts such as what you might encounter in a race or fast group ride. Similarly, if you are a crit racer, time-trialist, or track cyclist, it is important that you understand that your max HR will be lower than an endurance cyclist. This is due in majority to the difference of metabolic energy production employed during competition in your event. Short range, high intensity cyclists rely heavily upon anaerobic metabolism for energy production, in part because of its ability to fill the energy void more quickly than aerobic metabolism. However, because of the reduced need for oxygen, the VO2 max of a cyclist in this category is not incredibly high. Furthermore, the percentage of VO2max in which LT is breeched is very low (x<40%). In other words, you show me a cyclist with a very high VO2max, but who achieves LT at a very low percentage of VO2max, and I will show you a cyclist with a remarkable genetic potential.

Zone calculation is incredibly important especially as your fitness levels begin to reflect your training modes. As you become more aerobic you begin to delay the onset of anaerobic respiration, which in turn, demands more of your heart to continue delivering a steadily increasing supply of oxygen. This, of course, will correlate with an increase in your VO2max. Without properly accounting for this upturn in fitness via zone calculation and adjustment, you will not be delivering the progressive overload your body needs to continue adapting- which means that you can write your own ticket to plateau county.

The point that I am trying to make is that for you to be consumed with max HR is just as futile as consuming yourself with VO2max. These two near-functionless metrics are the metaphorical white bread surrounding the real flavor of the sandwich. While their value has meaning and is certainly a key indicator of overall fitness, training with these two parameters alone would be like walking into the Louvre, taking a few snapshots of the Mona Lisa, and then heading for the exit. Your overall aerobic physiological profile as related to race/event performance is a complex minutia of detail; when examined can provide a level of clarity that makes endurance training a questionless science NOT an art.

Your performance is determined NOT by the overall value of VO2max or max HR, but by the percentage of both metrics you are able to maintain for the longest period of time. Understanding and training on this principle will maximize your aerobic capacity, prevent physiological plateau, and optimize your fuel ratios.