IF YOU HAVE EVER watched a track meet on TV and seen an 800-meter race (a half mile, run in two laps), you may have heard a commentator comment on how tough that race is to train for. Runners ask themselves, do I train like a 400-meter sprinter, or do I train like a miler? It’s an odd distance physiologically and can be tough to dial in. The half-marathon offers a similar complication: Do I train like a 10K runner or like a marathon runner? It’s a tricky question, and not all coaches agree on the answer. But, as with most problems in running, it comes down to you individually, and in this case your physiology will point you in the right direction.
I have coached a few people who excelled at shorter distance (5K and 10K) but decided they wanted to try the half-marathon distance. Unfortunately, their approach to the half-marathon, which is twice as long as a 10K, was exactly the same. Most of them were too fast in their workouts, with many of them simply trying to run hard and see how well they could hang on.
Think about it this way: Consider what goes on when you train for a 5K. First, it’s a relatively short race, measured in minutes and not hours. Second, it’s almost a pure speed race, meaning that we have the endurance to cover the distance, and we tend to want to see how fast we can cover it. Finally, if you go out too fast, it hurts, but the amount of suffering is limited by the amount of race left. If you do crash and burn, most likely it will be for less than a mile.
Now, extrapolate to a 13.1-mile race. If you go out too hard at this distance, you can suffer for a very long time. What this all means is that having an idea of why we are suffering and the physiological basis behind it is critical to our success. Without a basic understanding, we are liable to make the same training mistakes over and over.
Knowing about physiology, in particular for the half-marathon distance, is critical for reaching your desired race goals. For a full marathon, no matter if you are a local legend or are running your first marathon in 4-plus hours, everybody is training the same energy systems. In other words, how your body uses energy, what systems it stresses for speed and endurance, and how fast it is using those energy sources are the same for all marathoners. Success at any level in marathoning depends on how well you can adapt to specific training principles. With the half-marathon, in contrast, smart training—specifically what systems you train—is far more dependent on what kind of runner you are and your individual race goals. Generally speaking, for faster runners—those looking to run the half in under 1 hour and 45 minutes—the training emphasis should be on increasing individual lactate threshold (or anaerobic threshold). Why? Because those runners will hover around that threshold for the entire race. For runners on the other end of the spectrum (wanting to complete the half-marathon in 3-plus hours), the goal should be improving aerobic pathways, since these runners may not approach their anaerobic thresholds (at least for the same duration that the faster folks will). Runners in between the two ends of the spectrum will need a blend of everything in fairly equal proportions. A lot to take in? Don’t worry, this chapter will walk you through it.
The human body is a beautifully complicated piece of machinery, but at the end of the day, if you want to race at your best, there are just five components of your physiology that you should understand. You may have heard these terms tossed about and wondered what they meant. I’ll break them down to arm you with what you really need to know in your training. These five key components are as follows:
// running-specific muscles
// VO2 max
// anaerobic threshold
// aerobic threshold
// running economy
When it comes to physiological movers and shakers, the musculature system is king. More than 600 muscles in your body work to create motion and force. They allow your heart to beat, your eyes to move, your food to digest, and your legs to run. The three main types of muscle fibers are cardiac, smooth, and skeletal. While the cardiac muscle makes your heart beat, and the smooth muscle lines your intestines, pushing food through your system, the skeletal muscle plays the starring role in human locomotion. Skeletal muscles make running possible.
The skeletal muscles are responsible for generating physiological movement and also are where the majority of energy is stored. These muscles include slow-twitch fibers and fast-twitch fibers, the latter of which have several subcategories. Each muscle contains both types of muscle fiber, which are bound together like bundles of cable, each bundle consisting of a single type. Thousands of these bundles constitute a muscle, and each individual bundle is controlled by a single motor neuron. The motor neurons are located in the central nervous system, where they work to control muscles and, in turn, movement.
Together, the fibers and the motor neurons make up the motor unit. Because each bundle contains only one type of fiber, a bundle of slow-twitch fibers and a bundle of fast-twitch fibers will receive information from the brain via separate motor units. If one motor neuron is activated, a weak muscle contraction occurs. If multiple motor neurons are activated, a more powerful muscular contraction is created. Why is all this important? Ultimately, the structure of the skeletal muscle system dictates running ability. So the better you understand your own physiology, the smarter your training will be. Let’s look closer at the types of muscle fibers.
Your family tree plays an important role in determining your potential as a runner. If your parents endowed you with an abundance of Type I muscle fibers, also called slow-twitch fibers, you have a leg up on the competition. These fibers are particularly important for endurance events because of their efficient use of fuel and their resistance to fatigue. Slow-twitch fibers are aerobic, meaning they use oxygen to transfer energy. This is a result of the fact that they have a large area of capillaries and, therefore, a much greater available supply of oxygen than do fast-twitch fibers. Additionally, these fibers have the machinery necessary for aerobic metabolism to take place. Known as the mitochondria, this machinery is often referred to as the “powerhouse of the cell.” Thanks to the mitochondria, you are able to use fats and carbohydrates as fuel sources to keep your muscles working and your body running.
True to their name, the slow-twitch fibers also have a slower shortening speed than the other types of fibers, which serves an important function for endurance runners. While these fibers cannot generate as much force as the others, they supply energy at a steady rate and can generate a good amount of power for an extended period. In addition to being slower to contract, Type I fibers are only about half the diameter of fast-twitch fibers. Although they are smaller and slower, they are also more efficient and persistent, warding off fatigue during a long haul on the roads.
Type II fibers, also known as fast-twitch fibers, are also genetically determined and are the slow-twitch fibers’ more ostentatious counterpart. They are bigger and faster, and they pack a powerful punch, but they also fatigue rapidly. Because these fibers have very few mitochondria, they transfer energy anaerobically (without the use of oxygen). These forceful contractions use such large amounts of adenosine triphosphate (ATP), basically a high-energy molecule, that they quickly tire and become weak. That is precisely why the Olympic 100-meter champion can run a record-setting pace only for the length of the homestretch, but the marathon champion can maintain a record-setting pace for 26.2 miles. Two different muscle fiber types, two different results.
The Type II fibers are further divided into subgroups, two of the most common being Type IIa and Type IIb, also known as the intermediate fibers. The Type IIa fibers share several characteristics with slow-twitch fibers because they have more mitochondria and capillaries than other types of fast-twitch fibers. As a result, Type IIa fibers are considered to be aerobic, although they still provide a more forceful contraction than slow-twitch fibers. By contrast, Type IIb fibers contract powerfully, transfer energy anaerobically, and fatigue quickly. See Table 2.1 for a brief comparison among fiber types.
All humans have both Type I and Type II muscle fibers, but the distribution varies greatly. Most people, regardless of gender, have a Type I fiber distribution of 45–55 percent in their arms and legs. Individuals who are fitness conscious but not completely devoted to training can see a Type I distribution of around 60 percent. Meanwhile, trained distance runners tend to have a Type I distribution of 70 percent, and elite marathoners have an even greater percentage than that. Herein lies the challenge. When it comes to running a half-marathon, Runner A, who has a high proportion of Type I fibers, will naturally be better off than Runner B, who has a low Type I and low Type IIa distribution. So how does Runner B get around his own physiology?
Luckily for both runners, the body is an amazing machine that can adapt to a myriad of stresses. In the field of exercise physiology, stress denotes the repeated and intense training that leads to certain physiological adaptations. Researchers have long sought the key to muscle fiber conversion, hoping to discover how a person, such as Runner B, could actually change the composition of her muscles via training stress. Although much of the research remains inconclusive, it is agreed that elite distance runners have a greater proportion of Type I fibers than the average recreational runner, and that those Type I fibers are necessary for a fast marathon or half-marathon performance (see Table 2.2 for a comparison among different types of runners). What we don’t know is if you are genetically bound to a particular muscle fiber arrangement or if you can change it with physical training through certain training stresses. Although it may be too early to make any definite statements about conversions from Type I to Type II fibers, it has been shown that transformations can take place within the Type II fibers. Even after a relatively short training block of 10–12 weeks, a runner can display a transition from anaerobic, fatigable Type IIb fibers to the more aerobic, fatigue-resistant Type IIa fibers. This is great for an endurance runner. It shows that training elicits tangible physiological changes that create performance advantages and real improvements. There is much hope for Runner B.
Whereas all endurance athletes will benefit from fat-burning increases, glycogen saving, and having an abundance of slow-twitch fibers, there is no “one size fits all” type of muscle fiber disbursement that is best for all half-marathoners. For them, the ideal ratio depends on how fast or slow they run. For instance, faster runners may have a large number of slow-twitch fibers, but because of the intensity with which they are running, they are also probably helped a fair amount by their collection of intermediate fibers. These runners must generate a high amount of force to maintain a fast pace. Alternately, slower runners do best if they train like marathon runners, which means having mostly slow-twitch fibers and a high level of fat utilization and glycogen storage, because their intensity is lower and their time on their feet is significantly longer—perhaps double that of their faster counterparts.
Regardless of genetics, training remains a vital predictor of running performance. Although genetics dictate what kind of work you may be innately suited for, the right training helps you maximize your individual potential. We will show you how this can be done, no matter what your DNA might say. To get your muscles to respond the way you want them to on race day, you must train them to fire in a particular manner. It all starts with a signal sent from the motor units in the central nervous system, which begins by recruiting the slow-twitch fibers. You continue to rely heavily on those fibers unless you do one of the following:
// increase your pace
// encounter a hill or another force that creates resistance
// run long enough to exhaust the slow-twitch fibers
Depending on their fitness level, some runners can go an hour at a modest pace before they begin to recruit the fast-twitch fibers; others can go as much as twice that long. Depending on how fast you are, you may rely on Type I fibers almost exclusively during your half-marathon. If you are on the course for a longer period, however, those fibers will begin to tire, and your body will begin to employ the Type IIa fibers, those slightly larger, aerobic, fast-twitch fibers. If you’ve trained properly, you’ll have enough leeway to get through the rest of your race using these fibers. They aren’t great for endurance running, but they are a good substitute for the exhausted Type I fibers. Issues arise when the undertrained runner is forced to go to the third line of defense: Type IIb fibers. Remember, these are built for power, and they fatigue quickly. If you are relying on these fibers to get to the finish, things will not end well.
What the Hansons Method seeks to do is teach you how to maximize the use of the Type I and Type IIa muscle fibers, without having to resort to the Type IIb fibers.
If muscle fibers are in the driver’s seat when it comes to endurance potential, then VO2max works in the pit, constantly providing assistance. VO2max stands for “volume of oxygen uptake,” defined as the body’s maximum capacity to transport and utilize oxygen while running. When a person’s VO2max is 50/ml/kg/min, it is read “50 milliliters of oxygen per kilogram of body weight per minute.” What you really need to know is that the higher the number, the better. Although VO2max is often considered the gold standard of fitness, it doesn’t always serve as the best predictor of running performance. In fact, elite marathon runners tend to have a slightly lower VO2max than elite 5K and 10K runners. Still, though it isn’t the single most important predictor of your racing potential, it remains a significant piece of the puzzle. Generally speaking, faster half-marathon runners tend to have a slightly higher VO2max than slower runners because, as discussed, the slower runners tend to adapt more like a marathon runner in terms of fat utilization and fiber type, and they have slightly lower VO2max levels. VO2max will improve with training. Thus, slower runners can improve their VO2max—and thus their performance—with an increase in training. Let’s examine this more closely.
Because blood carries oxygen to the muscles, one must look at the heart when considering VO2max. Like the skeletal muscles, the heart muscle can be strengthened with work, thus allowing it to pump more blood and deliver more oxygen to the muscles. The heart adapts to training stress in the same way the muscles in your legs do. Consider the positive adaptations related to the heart that occur as a result of endurance training. Four of these adaptations, shown in Figure 2.1 and described below, are considered the central components of VO2max:
CIRCULATION OF THE CORONARY ARTERIES IMPROVES // Improved circulation means more blood reaches the heart.
VENTRICLE WALLS THICKEN, PARTICULARLY THE LEFT VENTRICLE // As these thicken, the force of the contractions becomes greater, pumping more blood into the circulating arteries.
THE CHAMBER OF THE VENTRICLE BECOMES LARGER // This allows for more oxygenated blood to be stored within the ventricle, which is then circulated throughout the body.
PULSE DECREASES // When the cardiac muscle is strengthened, it doesn’t have to work as hard to do its job.
In sum, more blood is pumped with greater force and less effort. Because the heart has bigger chambers that hold more blood, heart rate slows across all running paces, making the entire system more efficient and healthier.
The heart supplies blood to the body, and the better it can deliver large amounts of blood into the bloodstream, the more efficiently the oxygen in the blood reaches the running muscles. What’s more, the adaptations don’t stop with the heart; they also affect the blood itself. Indeed, blood volume has been shown to increase with endurance training. Red blood cells, the most common type of blood cells, are the main means through which oxygen is delivered within the human body. With endurance training, the hematocrit level, the amount of red blood cells within the total volume of blood, decreases. This means that since total blood volume is higher and the blood itself is less viscous, it can travel through the heart and arteries with much greater ease. Think of the difference between new oil that has just been put in your car and the gunk that’s been sitting in the engine for the last 15,000 miles. A lower hematocrit level equates to less wear and tear on your system because, as the red blood cells become larger with training, you lose less oxygen-carrying capacity. Although it may sound counterproductive, since plasma volume increases, the hematocrit level decreases because it is expressed as a percentage of volume. So even though the percentage is lower, the total number of red blood cells can be higher. Remember, 20 percent of 100 equals 20 red blood cells, and 20 percent of 500 equals 100 red blood cells, giving you more bang for your buck.
With endurance training, the heart becomes a stronger pump, and the blood supply becomes bigger and better, but none of that matters if the muscles cannot use the massive amount of oxygen that is now being dropped off at their doorstep. The actual delivery of oxygen to the muscles happens in the capillary bed, which is the end of the line for the artery. Some of these capillaries are so small that only one red blood cell can drop off its bounty of oxygen to the muscle at a time. From there, the red blood cell begins its journey back to the heart and lungs, where it is reloaded with oxygen. During rest, many of these capillary lines lie dormant. As you begin running, the lines open up, allowing muscles to accept an increasing amount of oxygen to meet the demands of exercise.
While improving the central components of VO2max is important, having a bigger left ventricle to pump more blood doesn’t do much good if the muscles that are being used can’t handle the changes. Luckily, our running muscles, as we discussed, adapt simultaneously. Some of the key peripheral components that we see through endurance training, as shown in Figure 2.1, are the following:
INCREASED CAPILLARY DENSITY // A larger density of capillaries means that oxygen can exchange cells faster and more efficiently, the end result being that the exercising muscle gets the oxygen it needs to continue to exercise.
IMPROVED MITOCHONDRIAL ENZYME LEVELS AND ACTIVITY // Think of enzymes as tools that make work easier. They reduce the amount of energy required to make a reaction occur. With higher levels, reactions within the mitochondria can allow more work to be done at the same rate.
IMPROVED MITOCHONDRIAL DENSITY // The mitochondria are where fats and carbohydrates are presented as fuel for exercise, so the more mitochondria we have, the more fat that can be used as fuel to maintain aerobic intensity.
INCREASED SIZE OF EXISTING MITOCHONDRIA // Bigger mitochondria allow more fuel to be processed at a single site. If we can process more fatty acids through bigger and more mitochondria, we reduce the need for carbohydrates to be used and increase the needed intensity it takes to prompt the anaerobic system (reliance on carbohydrates for energy).
The bottom line is that the body is remarkable at adapting to training. It will do everything it can to support a given activity and become better at it. VO2max is the ceiling for your aerobic potential, but it is not the overall determinant of potential performance. When your aerobic capacities become maxed out, your anaerobic faculties are right on their heels. As a result, other physiological variables contribute to how well a person can run a half-marathon.
Although it isn’t necessary to determine your VO2max, and we can guarantee the number will climb with additional endurance training, it is a great indicator of progress. There are a number of ways to figure out your VO2max, some more expensive than others. On the high-precision and high-cost end of the spectrum, you can visit your local gym and have your capacity tested with an array of fancy equipment. This will require you to run on a treadmill with a breathing tube, increasing your speed incrementally. Twenty minutes and $100 later, you’ll have a printout with some cold, hard data. For a similar experience but potentially less cost, look into signing up to be a guinea pig at your local university’s exercise physiology lab. Graduate students often can provide you with a wealth of information, and you usually won’t have to shell out a dime. I am a believer in lab testing for the sake of improvement, provided the feedback is of practical use to you. What good are numbers if you can’t apply them? Both as an athlete and as a coach, when I look at VO2max and thresholds, I am only interested in whether they show improvement. Unfortunately, the results of exercise lab tests often omit the corresponding paces for these levels and thresholds. For example, when you get tested, the technician will often give you a number such as 50 ml/kg/min and tell you whether that is good, average, or below average. That’s great, but how do I use that information? What does it mean for me? If you choose to be tested, try to obtain the paces at which you are reaching certain physiological levels. You can then translate that information directly into your training paces.
If you’re not interested in getting rigged up to a machine, consider doing a field test. I use the Balke test, for which you need only a track, a stopwatch, and a calculator. Although the equation can vary slightly, the following is used by well-known running coach Dr. Joe Vigil, an expert in the world of running science:
VO2max = 0.178 × ([m ÷ 15] − 150) + 33.3
We solve this equation by completing the Balke test. To complete the test, do a thorough warm-up and follow these steps:
1. On the track, run fast for 15 minutes, covering as much distance as possible. (Remember to pace yourself. Don’t run as hard as you can from the start, but rather build into it, so that you can be running the fastest over the last few minutes.)
2. Convert the distance you have run into meters. To do this, multiply the number of laps by 400 meters (1 lap = 400 meters on a standard track).
3. Take the number in meters and convert it to meters per minute by dividing it by 15 (the number of minutes you ran).
4. Take the number from step 3 and subtract the first 150 m.
5. The remaining number is then multiplied by 0.178 and added to the base of 33.3. Note: If you don’t have a speed of greater than 150 m/min, take the difference between your speed and 150, multiply by 0.178, and subtract that number from the base of 33.3.
For example, we want to solve for this equation:
VO2max = 0.178 × ([m ÷ 15] − 150) + 33.3
Our runner completes the test, covering 10 laps in 15 minutes. He converts laps to meters and replaces the “m” with a number:
10 laps × 400 m/lap = 4000 m
The equation now looks like this:
VO2max = 0.178 ([4000 ÷ 15] − 150) + 33.3
Next, the runner solves within the brackets:
[4000 ÷ 15] or 266.67
Now the equation looks like this:
VO2max = 0.178 (266.67 − 150) + 33.3
Finally, the runner simply solves the equation:
VO2max = 0.178 (116.67) + 33.3
VO2max = 20.77 + 33.3
VO2max = 54 or, more precisely, 54 ml/kg/min
This means that our runner’s current aerobic fitness is 54.
After determining your baseline VO2max, you can repeat this test in the middle of your training to check your progress. Keep in mind that the more advanced the runner, the fewer changes are seen. What can always change, however, even if only slightly, is the pace you can run at your VO2max. That’s what really matters in the end.
As discussed previously, long-distance running relies heavily on the oxygen supplied by the aerobic system, which is more efficient and provides greater endurance than the anaerobic system. The anaerobic system is powerful and explosive, but it functions without oxygen and therefore can provide only short bursts of speed before energy stores are depleted, lactic acid builds up in the muscles, and running ceases. While lactic acid, or lactate, has gotten a bad rap as a soreness-inducing, fatigue-causing by-product of high-intensity exercise, it actually serves as an energy source for the muscles, allowing them to squeak out a bit more work before bonking. Research now tells us that the fatigue that occurs at that point is caused by another physiological phenomenon. The real culprits are the electrolytes—sodium, potassium, and calcium—that are positioned along the muscles, each with its own electrical charge that triggers muscle contractions. At high intensities and over time, the potassium ion outside the cell builds up and cannot switch places with the sodium ion inside the cell. This leads to weaker and weaker muscle contractions, a condition called neuromuscular fatigue, meaning your body will soon slow to a sputtering halt.
Not only is blood lactate not the villain we once thought it to be, but we’ve also come to see that it plays a key role in distance running. The aerobic system supports a moderate pace for long periods because the lactate that is produced is simultaneously processed and removed. However, as the aerobic system fatigues or the intensity increases, you become more dependent on the anaerobic system and, in turn, reach a point where you produce lactate faster than your body can get rid of it. Referred to as lactate threshold, onset of blood lactate, or anaerobic threshold, this is the tipping point at which lactic acid starts to build up in your bloodstream.
Anaerobic threshold is particularly important because it has been identified as perhaps the best predictor of endurance performance. It occurs at anywhere between 60 and 90 percent or more of a person’s VO2max, so as you get closer to your VO2max, blood lactate begins to accumulate. The best of the best tend to have an anaerobic threshold exceeding 70 percent of VO2max. Training may raise your VO2max only a few points, but it can have a significant impact on anaerobic threshold. If you look at a group of elite marathon runners, their VO2max levels will be similar; what tends to separate 1st place from 10th place is anaerobic threshold. While VO2max may separate the national class from recreational runners, anaerobic threshold separates the champions from the contenders.
As with VO2max, testing your anaerobic threshold is always an option, but it requires some guesswork unless you have the testing done in a fancy lab, with the numbers printed out for you. Our advice is to see how your body responds to the workouts on the plan. As mentioned, anaerobic threshold pace can be maintained for about an hour. If you don’t have these paces to use, then ask yourself, “Can I hold this for an hour straight?” Adjust your pace accordingly based on your response.
Remember that anaerobic threshold is the point at which the aerobic pathways are still providing energy for muscle contraction, but they can’t do it fast enough to provide all the required energy. This is where the anaerobic pathways begin to make up the difference. As a rule of thumb, a person can run at his or her anaerobic threshold for about an hour. As you may have guessed, this becomes increasingly important for elite runners, whose half-marathon times tend to hover around an hour. For these folks, having a high anaerobic threshold is probably more important than being able to burn fat for fuel. The higher this threshold is, the faster they can cover the distance before having to slow down; thus, raising this level is critical for their individual success. For slower runners, anaerobic threshold may be a better representation of their 10K times because their 10K times probably hover closer to that 1-hour mark than do their half-marathon times. So, although anaerobic threshold is important for slower runners (and even more so as they become faster), the ability to burn fat and save glycogen will probably have more bearing on their success.
We can push the threshold higher via training. By running farther and faster, we train our bodies to rely more heavily on the aerobic pathways, thus improving endurance and increasing the time it takes to reach the point of anaerobic reliance. One of the big differences between the Hansons Method and traditional training programs is that we teach you to stimulate aerobic metabolism through a large volume of aerobic training, not high-end anaerobic work.
All this talk about energy systems may have you wondering where that energy comes from in the first place. The short answer: fats and carbohydrates. As an endurance runner, you should focus on training the body to use fat as the primary source of energy. Our bodies store very small amounts of carbohydrates for quick energy, but our fat stores are nearly endless. Even if you have only a small percentage of body fat, your system has plenty of fat for fuel. Fat is particularly high in energy because it provides nearly twice as many calories per gram as do carbohydrates. The only problem is that the oxidation of fat to energy is slower than the oxidation of carbohydrates. For most people, fat serves as the main source of energy for up to about 50 percent of VO2max because up to that point the fat can be processed fast enough through the mitochondria to supply the demands that running requires. For most runners, however, 50 percent of VO2max is painfully slow. After that point, whether as a result of distance or intensity, the body looks to burn carbohydrates. The term aerobic threshold reflects the pace at which the proportion of fat and carbohydrate being used for fuel is about 50/50. See Figure 2.2 for a graph that illustrates the contribution of fat and carbohydrate based on running intensity.
The reason carbohydrates (glycogen) provide the majority of energy at faster paces is because fat is metabolized slower than carbohydrate. The downside of relying on glycogen stores for energy is that you have only about 2 hours’ worth, and once they are gone, your run is over. When you burn through your stored glycogen, your body will draw upon the glucose in your blood, which runs out even more quickly. The result is “hitting the wall” or “bonking.” While bonking is more common during a full marathon, poorly prepared or poorly fueled runners can certainly experience it in the half-marathon distance. How do you know if you have hit the wall? For one, your pace slows perceptibly, and the feeling associated with bonking has been described as similar to dragging a 300-pound anchor behind you. Although this was once thought to be an unavoidable rite of passage for long-distance racers, a smart training plan will help you skirt the wall altogether. It’s all about burning fat for a longer time to put off drawing on those limited carbohydrate stores.
Being able to “burn” fat more efficiently is invaluable across the spectrum of paces. Faster runners are running at a high percentage of their VO2max for a significant amount of time, and a larger proportion of their energy expenditure is coming from the use of carbohydrates. So, even though they are likely to finish the half-marathon in less than 2 hours, they can still nearly exhaust their stores because the percentage of glycogen usage is so high. Meanwhile, those on the slower end of the spectrum are out on the course for more than 2 hours, and being able to utilize fat better will save their glycogen stores and ensure that they can complete the race and even finish strong.
Luckily for the distance runner, it is possible to train the body to burn fat longer. The speed at which fat can be processed doesn’t change with training, so to be able to use more fat, we have to burn a higher volume of it. To do this, we need more metabolic factories (the mitochondria, which, as mentioned earlier, are the powerhouse of the cell). Aerobic training, such as running, helps to increase the number of mitochondria, which in turn introduces new enzyme activity and oxygen to the system. While the mitochondria are not necessarily producing more quickly, they are bigger and more plentiful, which allows fat to be oxidized and turned into energy for muscle contraction. With the increase in energy from fat, the glycogen in the muscles isn’t tapped until later, saving it for faster paces. Basically, the wall is pushed back and, with any luck, never reached.
Figures 2.3 and 2.4 illustrate what has been discussed so far. Figure 2.3 represents typical results of a VO2max treadmill test of a trained runner. For the most part, as the intensity increases, you observe a linear increase in the amount of oxygen used. At our threshold points, we can see slight deflections on the graph. The first represents the aerobic threshold; the second represents the anaerobic threshold. Figure 2.4 represents the actual blood lactate measurements from a treadmill test. By graphing the amount of lactate in the blood at set intervals of a test, we can again see the deflection points that coincide with our threshold points.
The take-home here is that improving one’s aerobic threshold is vital for a successful half-marathon, regardless of pace. Improving the ability to process fat as a fuel at higher intensities will give you more stamina and ultimately make you faster. From a training perspective it shows why easy runs, which are a large part of the Hansons Method, facilitate quality adaptations in the short term and long term. They are far from “junk miles” and should not be omitted.
Running economy, which describes how much oxygen is required to run a certain pace, is the final physiological topic runners should understand. Consider this scenario: Runner A and Runner B both have the same VO2max of 60 ml/kg/min. It might take Runner B 50 ml/kg/min to run a 6:30 mile, while it takes Runner A 55 ml/kg/min to run the same pace. Given this, Runner B is more economical than Runner A but, more important, is probably faster too. See Figure 2.5 for a graphic example.
Although there has been much debate over the effects of running economy, two facts are clear. First, running economy depends on a high training volume. You don’t need to pound out 120-mile weeks, but your mileage should be sufficient for the distance for which you are training. When I say “sufficient,” I am referring to the amount of mileage required to perform well in your event. For instance, 20 miles a week is sufficient volume for a beginning 5K runner but not nearly enough for an advanced half-marathoner. This varies depending on the event you are training for, the number of months and years you have been running, and how fast you are attempting to run.
The second component of running economy is speed training. By training at a certain pace, you become more economical at that pace. Because the goal is to improve running economy at race pace, you must spend an adequate amount of time training at race pace. This also underscores why it is important not to run workouts faster than prescribed and why pace is such a key part of our program. When you opt to run faster than suggested, you are training at a level that you may not be ready for, based on actual race performances. Training above suggested paces turns workouts into something they were not intended to be; for example, easy runs may now resemble tempo runs, tempo runs become strength runs, and strength runs become speed runs. These paces may feel achievable at first, but it is our experience that the majority of people who train too fast end up overtrained, burned-out, or injured. If you feel strongly about training at a faster pace, then it is important to run (or simulate) a race to confirm that you are ready to move to a more aggressive pace goal.
The validity of running economy is not without some controversy. Some coaches and well-known exercise science folks question whether running economy matters when comparing runners. If the runners are comparable in race times, then maybe it does. If they are not, it may not really matter. Put another way, if you are a construction worker looking to buy a new pickup, do you care about the economy of a coupe? Probably not, because it’s not what you want to buy. But if you find you can get a new F150 that gets 30 miles per gallon without a loss in performance, your ears perk up, right? This is especially so if the truck outperforms others on the market. What I am saying is, economy is important, but use it as a way to evaluate your own personal improvement. If you improve your running economy, then you are going to get faster. If you process fat better and improve your VO2max and your anaerobic threshold, you will be a better runner. And because of these improvements, you will be able to run faster using less energy. For instance, prior to training, perhaps you ran 7:00 minutes per mile and were at 75 percent VO2max, and now you are running the same pace but at 70 percent VO2max. Running economy allows you to quantify such changes and gives you a look at how these factors have helped you to improve.
By understanding the physiological factors involved in optimal endurance training, you can understand the justification for each workout. As muscle fibers adapt to running stress, VO2max is optimized, anaerobic threshold improves, and the ability to burn fat at higher intensities increases. In the end, improved running economy is the result of consistent, optimal training. It all comes down to the tiny biological happenings of the human body; increased capillarization, an increased number and size of mitochondria, and greater mitochondrial enzyme activity equate to less oxygen being needed to run the same paces. The beauty of the Hansons Method is that it allows runners of all abilities to do the same workouts but at paces that are going to benefit the individual. The physiological adaptations are what make you better, and the Hansons Method is designed to ensure you develop these adaptations.
