The term “acid rain” was coined in 1872 by Robert Angus Smith to describe the corrosive effect that atmospheric pollution was having upon the environment. Factories were pumping galactic clouds of sulfur dioxide and nitrous oxide into the air, which then mixed with rain, snow, fog, smoke, and dust, before falling back to the earth as an acidic rinse and soak. When you run hard—really hard—you create a similar atmospheric effect within your muscle fibers. As you rely more heavily upon anaerobic energy (energy that’s produced outside the mitochondria without oxygen), you create an acidic pH, which in turn is believed to shut down muscle fibers, trigger nausea, and saturate your body with almost unbearable fatigue. While not a problem in longer runs and races, acidic pH can be a killer during high-intensity efforts.
Your body’s pH is a measurement of the hydrogen ions in your body. More hydrogen ions create an acidic pH, while fewer result in an alkaline pH. Your body prefers a slightly alkaline pH, measuring between 7.35 and 7.45 on a scale of 1–14. A pH below 7.0 is considered acidic, while anything above that is considered alkaline. The term “pH” has been variously reported to mean both “power of hydrogen” and “potential hydrogen.”
So what does this have to do with running?
Running at an intensity that demands a large contribution from anaerobic energy—think shorter races and fast-paced workouts—results in an increased accumulation of hydrogen ions. When your pH drops below 7.0, you begin to suffer from acidosis. Acidosis is accompanied by fatigue, an inability to generate high muscle contraction force, and a burning sensation in affected muscles. If left unchecked, it can lead to a state of near-incapacitation, one that runners refer to as “rigging” (short for “rigor mortis”), “tying up,” or having the “bear jump on your back.” At a pH of roughly 6.4, your legs become dead weight. Cyclists have been tested with muscle pH as low as 6.4, and back in 1983, Dr. David Costill, et al., measured runners’ leg-muscle pH at 6.63 following 400-meter sprints. Because fatigue at high intensities has traditionally been associated with lowered pH, runners train to lessen acidosis within muscle fibers (by exporting hydrogen ions from the fibers) and to buffer (explained in detail later in this chapter) the hydrogen ions within the fibers, thereby neutralizing them.
It’s important to note, however, that this theory of fatigue has been challenged in recent years. Many researchers have discounted the effect of acidosis and proposed alternative theories. A major problem with much of the original research on acidosis was that tissue used in the studies (removed from rodents) was refrigerated, altering the results. When new studies were performed on warmed tissue—closer to normal body temperature—the effects of acidosis disappeared to a large degree. As often happens, however, these later studies were in turn contradicted. A 2006 experiment by Knuth, et al., tested the effect of acidosis upon warmed muscle tissue. Knuth concluded that “the fatigue-inducing effects of low pH … are still substantial and important at temperatures approaching those [in living tissue].” Stalemate.
Which leaves us with a bit of a conundrum. Should we reject the theory of acidosis? Maybe ignore alternative theories? The answer is that we’ll cover both. We’ll discuss alternative theories of fatigue in Chapter 13. As for this chapter, we’ll take the advice of Dr. Ernest W. Maglischo, writing in a 2012 issue of the Journal of the International Society of Swimming Coaching: “I don’t believe a radical change [in training] is required. Our training methods have worked even though their reasons for doing so may be different than we once thought … [Until] we know for sure that acidosis is not involved, it would be wise to continue training to improve buffering capacity.” In other words, if training based on low pH ain’t broke, don’t fix it.
Training pH began with building more mitochondria in Chapter 8. More mitochondria create more aerobic energy, a process that consumes hydrogen ions and decreases the required input from anaerobic energy production. In this chapter, we’ll look at two other ways to improve performance while neutralizing acidosis:
For buffers, we’ll try short sprints for a change of pace. Training the lactate shuttle will introduce an entirely new type of workout into your schedule: Cross training. You’ll learn how riding an ElliptiGO or romping through the woods on snowshoes can offer big performance gains.
Buffers are substances that neutralize the effects of hydrogen ions (acidic pH) within your muscle fibers. Examples of buffers are phosphates, bicarbonate, and some proteins.
If you never run harder than a jog, you don’t have to worry about buffers. You have plenty already to neutralize the small level of hydrogen ions you’ll generate. On the other hand, if you intend to run hard, you’ll need to fortify your buffering system.
Runners are sometimes surprised to discover that the first thirty seconds of a race (at any distance) are more anaerobic than the remainder of the race, with the exception of the final gut-wrenching kick to the finish line. That’s because it takes time for your aerobic system to get up to speed, at which point it provides the majority of energy for your effort. That makes the first thirty seconds the period when your buffers are most challenged. Since building more buffers requires overtaxing existing buffers, you’ll need to run short-duration reps that tap into the high anaerobic load of those thirty seconds. That means repetitions at near-maximum speeds, followed by plenty of rest to ensure that you replenish your anaerobic energy supply for the next rep (so that it won’t be fueled by your aerobic system).
Buffer training responds quickly, with maximum buffering capacity reached after only four to six weeks.
The “lactate shuttle” refers to the combination of mechanisms through which your body moves lactate within your cells and between your cells, which invites the question: What does a lactate shuttle have to do with reducing the effect of hydrogen ions—hence, acidic pH—within your muscle fibers? After all, lactate is a fuel, not an acid. But the truth is that lactate and hydrogen ions are joined at the hip. In fact, for decades they were thought to be one entity, lactic acid (see sidebar, “Lactic acid—friend or foe?” page 153). Although we now know that hydrogen ions, and not lactate, are the problem, there are several reasons why we can’t discuss acidosis without discussing lactate:
Because lactate and hydrogen ions accumulate at about the same rate, we can test blood lactate levels (lactate that has exited muscle fibers and entered the bloodstream) as a way to estimate acidosis within the muscle fiber. The more lactate in the bloodstream, the more in the fiber. And the more lactate, the more acidosis. It’s too expensive and difficult to measure fiber pH directly. As you can see in Table 9.1, some lactate accumulates at all running speeds. This is because both aerobic and anaerobic energy production are always ongoing (the percentage of each changes depending on your effort level).
When lactate levels within your muscle fibers get high—and as hydrogen ion levels simultaneously rise—your muscle fiber types respond differently. Slow-twitch fibers burn about 75–80 percent of produced lactate to fuel aerobic energy production in your mitochondria. Intermediate and fast-twitch fibers, however, lack similar lactate-burning capacity. So when lactate levels rise in faster fibers, these fibers go into the export business, shipping lactate to other muscle fibers, the brain, the heart, and the liver (where it’s converted to glucose).
Your muscle fibers use specialized transport proteins called MCTs to move lactate. MCTs are to lactate what tugboats are to larger vessels. MCTs can tow lactate to mitochondria, where it’s burned as fuel. Or they can push lactate—accompanied by hydrogen ions—out of the fiber. Or, when needed, they can import lactate from adjacent fibers and the bloodstream for use as fuel. Berkeley physiologist Dr. George A. Brooks dubbed this process the “lactate shuttle.”
|
Type of Training |
% VO2 Max |
Blood Lactate (mmols) |
|---|---|---|
|
Jogging |
60 |
0.8 |
|
Easy Running |
65 |
1.1 |
|
Moderate Running |
70 |
1.4 |
|
Faster Running |
75 |
1.9 |
|
Marathon/Slow Tempo |
80 |
2.6 |
|
Half-Marathon/Fast Tempo |
85 |
3.5 |
|
10K pace |
90 |
4.6 |
|
5K pace |
95 |
6.2 |
|
3K pace |
100 |
8.2 |
|
1 mile/1500 meter pace |
105 |
11 |
|
1200 meter pace |
110 |
14.7 |
|
800 meter pace |
115 |
19.6 |
|
600 meter pace |
120 |
22.9 |
|
400 meter pace |
135 |
26.1 |
|
200 meter pace |
150 |
19.6 |
|
100 meter pace |
155 |
11 |
TABLE 9.1 offers a comparison of average blood lactate levels at various running speeds (and roughly equivalent VO2 max). Blood lactate levels give an indication of rising acidity within muscle fibers, which is theorized to lead to fatigue in shorter races. Note: “mmols” is the abbreviation for millimoles; a mole is a unit of measurement in chemistry.
The lactate shuttle has two trainable limitations:
The traditional solution to these limitations is simply to increase the number of MCTs, which escort lactate and hydrogen ions out of fibers and pull lactate from the bloodstream into non-working muscle fibers.
Increasing MCTs to export lactate requires different training for different fiber types:
There’s also an untraditional solution for dealing with the problem of congestion—of a rising blood lactate level that slows facilitated diffusion of lactate and hydrogen ions from muscle fibers. And that solution is cross training.
Cross training (e.g., swimming, biking, snowshoeing, etc.) is loved by some runners and dismissed by others. The latter group correctly believes that cross training violates the specificity-of-training rule: Exercise you perform in practice must be as close as possible to the actual competition. But it’s this very lack of specificity that makes cross training perfect for improving your body’s ability to lower blood lactate levels while running.
Remember that a goal of training is to diminish blood lactate during hard running, thereby allowing hardworking muscle fibers to export more lactate and hydrogen ions through facilitated diffusion. What cross training accomplishes is to train muscle fibers that aren’t used during running—that are specific to the cross training activity—to increase their MCT levels, thereby increasing their ability to import lactate. Then, when you run, these non-working fibers can act as lactate drop zones, gobbling up lactate from the bloodstream.
“[Decreasing blood lactate] is one of the reasons I started to insert a little more cross training into my athletes’ training,” says Steve Magness, the head cross country coach at the University of Houston, a former coach for the elite Nike Oregon Project, an exercise scientist, and author of The Science of Running (Origin Press, 2014). “It’s not about replacing running. It’s about getting adaptations that might help you while running.”
To test his hypothesis, Magness did a basic lactate profile on himself. He then spent the next four weeks adding cross training and running circuits to his running schedule (see photo instruction in Chapter 12 for Jay Johnson’s running circuits). His goal was to train new fibers to take up lactate. When he tested himself again after the four weeks, his lactate profile had improved at every training pace.
Cross training offers an untapped reservoir for offloading lactate, simultaneously lowering blood lactate levels and aiding the removal of hydrogen ions from muscle fibers. Not only will you balance your pH, you just might find that variety is, indeed, the spice of life—and of training.
Developing your lactate shuttle and buffers involves much of the same training that we used for improving capillaries and mitochondria. At the same time, we’re introducing cross training to create lactate drop zones in slow-twitch fibers. Important training in this chapter’s photo instruction includes:
Training from other chapters that affects buffers and the lactate shuttle includes:
To see exactly how these workouts can be incorporated into your overall training program, skip directly to Chapter 15: Build Your Training Schedule, where sample schedules are available for runners of all fitness levels and abilities.
Cross training has long been a favorite form of alternative training for runners who are injured, interested in better all-around fitness, or simply looking for a change in their fitness routines. But now all runners have two very good reasons to make cross training a part of their programs:
Cross training increases your MCT transport proteins (shuttle buses for lactate) within muscle fibers, allowing you to transport lactate/hydrogen ions (the cause of acidosis) out of those fibers and import lactate into non-working muscle fibers—those fibers become lactate drop zones when blood lactate levels are high. This photo instruction will highlight eleven cross training options, demonstrated by Christian (whom you met in Chapter 2’s photo instruction); Emii, a martial arts athlete turned actress, pop entertainer, and runner; Roger Sayre, a former 2:30 marathoner and masters national cross country ski champion; and Callie Greene, a competitive cheerleader who uses running as base training, and who also builds all-around fitness with a mix of kickboxing, swimming, and stationary cycling.
The treadmill has existed as a popular indoor alternative to outdoor training since William Staub invented the PaceMaster 600 in the late 1960s, inspired by Dr. Kenneth H. Cooper’s book, Aerobics. While treadmill running might look like outdoor running’s indoor twin, it’s not. It’s different in several measurable ways. First, there’s no air resistance on a treadmill; you use less energy to run. To counteract this, use a 1 percent incline. Second, research shows that runners use a shorter stride, faster cadence, and more flat-footed landing on the treadmill. This recruits a slightly different mix of fibers, reduces running economy, and requires a rewiring of your nervous system (see Chapter 11). Third, you’ll run slower on the treadmill—studies show up to two minutes per mile slower than on the roads. So you’ll want to choose your setting based on effort, not pace. The good news is that all these changes ensure the creation of new MCTs in a larger group of muscle fibers. Other than running a little slower, train like you would on the roads and trails.
The elliptical machine was introduced in the 1990s and soon became a mainstay of fitness club cardio training. Elliptical machines have two foot-pedals (platforms) that move in an ellipse—meant to mimic the act of walking or running. You can adjust incline, resistance, and stride length (depending on the machine, stride length adjustments vary from just over a foot to almost three feet). Many models also include moveable handles, allowing you to work your upper body. For runners looking to improve upper body fitness, a must for developing the full range of MCT improvements, you’ll need to increase resistance to slow down your stride rate (rpms); this allows you to grasp the handles more easily. For runners focused on lower body training, you might want to release the handles altogether and increase your stride rate to mimic normal running. Some runners hold light weights in their hands (e.g., 12-ounce fishing weights) to improve balance while running hands-free. To perform workouts like fartlek and repetitions, increase both stride length and resistance settings.
The ElliptiGO is an elliptical bicycle, first marketed in 2010 and already gaining numerous adherents among elite open and masters runners. Like the elliptical machine, the ElliptiGO allows you to work muscle fibers beyond those recruited during running. Unlike the elliptical, the ElliptiGO doesn’t have moveable handles for upper body training. Some quick rules for your first ride:
Other than that, pick a duration and intensity that’s equivalent to a running workout.
Aerobics exploded onto the fitness club scene in the 1980s, fueled in large part by the 1982 release of Jane Fonda’s exercise video, Jane Fonda’s Workout. Given aerobics’ emphasis on full body strength and endurance, it remains a fun and effective way to create the kind of training adaptations required for better MCT/lactate function. While “aerobics” can mean anything from spinning to martial arts to stair climbing to boot camp, two specific forms have remained the most popular classes at fitness clubs for three decades running:
Aerobics is great for runners looking for a vibrant, social atmosphere for some of their training.
Kickboxing (and other martial arts) provide a combination of endurance, strength, and nervous system training. But kickboxing isn’t a sport you’ll want to learn from a book or DVD. You’ll need to find a local gym with either accredited personnel or instructors who are steeped in experience—instructors nationally ranked in kickboxing or other martial arts can be trusted to know their stuff. Also, realize that kickboxing isn’t just about snapping kick/punch combinations at a sparring partner. A good training session begins with a cardio warm-up that might include running, stretching, resistance training, and form drills, among other elements. Actual kickboxing instruction will involve learning combinations of kicks and punches, aimed both at space and the heavy bag. You’ll focus on form, balance, speed, strength, and endurance. Overall, the workout will challenge your body from head to toe, leaving you more fit than before you gloved up.
Cycling holds the allure of allowing runners to go faster and farther than is possible in running shoes alone. Plus you get to coast down hills! With a bike (road or mountain), you can train muscle fibers in the legs that you barely touch with running. You’ll need sunglasses or other eyewear for protection and either toe clips or clipless pedals and cycling shoes (both allow you to pull up as well as push down with each spin of the pedals, which powers the full rotation of each pedal spin and increases the workload for your muscles). Before riding, adjust the seat height so that it’s about 80 percent of your inseam, enough to allow a slight bend at the knees. Once you’re pedaling, pay attention to cadence. Many runners start with higher gears and put more “mash” than “spin” into their effort. Instead, make 60 rpm (revolutions per minute with each leg) your absolute floor, and, as your fitness improves, shoot for 80 rpm or more (advanced cyclists maintain rates of 80–110 rpms). If you find yourself rocking from side to side when riding, readjust the seat height until you’re more stable. Now ride fast, slow, up, down, far, and short until you’ve gotten a good all-around workout.
Riding the stationary bike—indoor cycling or “spinning”—garners most of the benefits of outdoor cycling, plus you can safely listen to music, control the weather, avoid run-ins with motorists (and annoying runners), and watch the latest episode of Game of Thrones, True Blood, or American Idol. As an extra bonus, you’ll never have to change a flat tire! First, adjust the seat height and then set the bike’s resistance, which is controlled by a knob/dial in some models and electronically in others. Begin your ride with moderate resistance, which equates to a flat outdoor ride. You can simulate acceleration or hill-climbing by increasing resistance. Or decrease resistance to enjoy the equivalent of a nice downhill ride. With some bikes, you can hook up to your computer and choose a virtual route or ride against a virtual competitor. To improve muscle fiber recruitment, try standing while pedaling during accelerations and climbs. And to combat rising body heat, set up a fan to help evaporate your sweat.
Pool running (along with the elliptical) is the preferred cross training activity for injured runners. It closely mimics your running motion and negates all landing impact. You only weigh about 10 percent of your normal body weight in water. By using an AquaJogger buoyancy belt (as pictured), you’ll have no trouble keeping your head above water. You’ll need a pool that’s deep enough to ensure that your feet don’t touch bottom. With some AquaJogger foot gear, you’ll literally be floating with every stride. This dramatically changes muscle fiber recruitment, as you no longer have to adjust for balance and weight distribution. Unlike running, your center of gravity—your hips in running—becomes a center of buoyancy, located at your lungs. Use your abdominal and back muscles to maintain a straight line from your head through your trunk, with an overall forward lean of about 3 percent (or a lean that corresponds roughly to the lean you employ when running). Move your arms and legs as if you were running. Perform your normal running workouts in the pool—just go by effort and duration, not time and distance.
Many runners avoid swimming for one simple reason: They sink. With their low body fat, elite runners fear ending up at the bottom of the pool. But even a runner with a little padding can find his or her hips and legs dragging through the pool like a boat’s hull taking on water. What gives? What gives is a lack of form and balance. At sea level, water is 784 times denser than air. If you’re not floating, you’re doing something wrong. Imagine that you have an axis running from your head down your spine, and that you have another axis running from shoulder to shoulder. Where those two lines meet is the “T.” You want to force the “T” downward into the water (known as “pressing the T”). This automatically brings your hips into position for kicking, while assuring a strong stroke. And you’ll want that stroke. You get a third more propulsion from your pull than from your kick. Both freestyle and butterfly are good strokes for cross training.
Snowshoeing is a great cross training option for those who live where it snows. All you need are a pair of snowshoes (both Atlas and Redfeather are good brands) and a pair of waterproof boots—if not waterproof boots, then leather hiking boots, or even running shoes covered by neoprene overshoe booties (for the cost conscious, plastic baggies will do). For beginners or those navigating rough terrain, poles are also advisable. When training, it’s best to find a packed trail (snowmobile trails are perfect). Because snowshoeing is more demanding than walking or running, you’ll want to begin your snowshoe sessions with outings over relatively flat terrain. Treat snowshoeing like altitude training, where you hold back slightly on your effort, and don’t be afraid to take walk or light jog breaks. Snowshoeing is similar in form to running, except that you lift your knees higher to clear the snow. For workouts that mimic tempo or 5K/10K repetitions, go by effort, not pace.
Cross country skiing is as good a VO2 max workout as you’re going to find. In fact, cross country skiers have recorded some of the highest VO2 max scores in history. Espen Harald Bjerke and Bjørn Dæhlie both recorded 96.0 for VO2 max, with Dæhlie’s out-of-season score indicating the possibility of an unfathomable 100+ score when at peak fitness. You can choose from two popular styles, either classic skiing or skate skiing. For both, you’ll need skis, boots, poles, and cold-weather gear.
For workouts, mimic running using effort and duration as your guides.