When you accumulate a high level of lactate, the hydrogen ions associated with lactate production turn off the enzymes used to produce energy and may interfere with the uptake of calcium, thereby reducing the muscles’ ability to contract. In other words, you can’t produce energy as quickly, so you’re forced to slow down. This explains why you run the marathon at an intensity just below your lactate threshold.
Brian Sell
Fastest Marathon: 2:10:47
Marathon Highlights:
Third place, 2008 U.S. Olympic
Trials; Ninth place, 2005 World Championships
Brian Sell should be an inspiration to every runner out there who is willing to believe that great things are possible through sheer hard work.
In high school, his best 3,200-meter time was a mediocre 10:06, more than a minute slower than the best scholastic runners in the U.S. Yet a decade later, Sell was able to average under 5:00 per mile for a marathon. As he said after placing fourth at the 2006 Boston Marathon, “I started thinking about how I just ran 26 miles faster than I could run two miles in high school. I just hope that people look at it and say, ‘Hey, if this yahoo can do it, then I can do it too.’ It’s just a matter of putting the miles in and working. It’s not so much how much talent you have.”
Obviously, to have become an Olympic marathoner, Sell was born with above average genetics for distance running. But that innate ability only really started to surface in 2004, by which time he had already been averaging well over 100 miles © per week for years. After leading the 2004 Olympic Marathon Trials for 19 miles but then fading to 12th, Sell could have been excused for thinking he wasn’t meant to run at the elite level. Instead, he got back to work – upping his mileage to 160 miles per week in marathon buildups – and continued to progress, making the 2008 Olympic team ahead of runners such as former world-record holder Khalid Khannouchi and 2004 Olympic silver medalist Meb Keflezighi.
Although few, if any, readers of this book are going to be able to handle repeated weeks of 160 miles, all can draw inspiration from Sell. First, consider his dedication to and faith in simply getting out the door and putting in the miles. How many other runners of Sell’s caliber in high school might potentially be 2:10 marathoners today? Put another way, how do you know how good you can be until you try?
Second, think about Sell’s ability to handle such high mileage. Being able to put in the training necessary to run a good marathon is itself a form of talent. Although you may not consider yourself blessed with a lot of “natural talent,” as judged by your ability to run a really fast 5K, you might very well have Sell’s ability to hold up to and absorb a lot of miles, which should translate to faster marathons. Again, how will you know until you try?
Finally, Sell is part of the Brooks-Hanson training group. They meet for distance runs most days and do almost of all their long runs and hard workouts together. Sell credits the group with pulling him through tough physical and emotional times in his training. You, too, can benefit from finding regular training partners who share your goals and are of roughly your speed.
With the correct training, adaptations occur inside your muscle fibers that allow you to run at a higher intensity without building up lactate. The most important of these adaptations are increased number and size of mitochondria, increased aerobic enzyme activity, and increased capillarization in your muscle fibers. These adaptations all improve your ability to produce energy using oxygen.
Mitochondria are the only part of your muscle fibers in which energy can be produced aerobically. Think of them as the aerobic energy factories in your muscle fibers. By fully utilizing your ability to produce energy without accumulating high levels of lactate, lactate-threshold training increases the size of your mitochondria (i.e., makes bigger factories) and the number of mitochondria (i.e., makes more factories) in your muscle fibers. With more mitochondria, you can produce more energy aerobically and maintain a faster pace. This is a relevant adaptation for marathoners because more than 99 percent of the energy needed for running a marathon is produced aerobically.
Enzymes in your mitochondria speed up aerobic energy production (i.e., increase the rate of production in your aerobic energy factories). Lactate-threshold training increases aerobic enzyme activity; this adaptation improves the efficiency of your mitochondria. The more aerobic enzyme activity in your mitochondria, the faster you are able to produce energy aerobically.
Oxygen is necessary to produce energy aerobically. Your heart pumps oxygen-rich blood to your muscles through a remarkable system of blood vessels. Capillaries are the smallest blood vessels, and typically several border each muscle fiber. With the correct training, you increase the number of capillaries per muscle fiber. With more capillaries per muscle fiber, oxygen is more efficiently delivered where it’s needed. Capillaries also deliver fuel to the muscle fibers and remove waste products such as carbon dioxide. A more-efficient delivery and removal system provides a constant supply of oxygen and fuel and prevents waste products from accumulating in your muscles as quickly. By providing oxygen to the individual muscle fibers, increased capillary density allows the rate of aerobic energy production to increase.
Glycogen is the form of carbohydrate stored in the body, and carbohydrate is the primary fuel used when racing a marathon. The two ways to ensure that glycogen stores last throughout the marathon are to train your body to store a large amount of glycogen and to train your body to conserve glycogen at marathon pace.
A large supply of glycogen in your muscles and liver at the start of the marathon enables you to work at a high rate throughout the race without becoming carbohydrate depleted. During the marathon, you use a combination of carbohydrate and fat for fuel. When you run low on glycogen, you rely more on fat, which forces you to slow down because fat metabolism uses oxygen less efficiently. With the correct training, your muscles and liver adapt to store more glycogen. Design your training so that toward the end of certain workouts, you run very low on glycogen; this provides a stimulus for your body to adapt by storing more glycogen in the future.
Because your body can store only a limited supply of glycogen, it’s an advantage to be able to use as much fat as possible at marathon race pace. Successful marathoners have developed their ability to use fat; this trait spares their glycogen stores and helps ensure that they make it to the finish line without becoming glycogen depleted. When you train your muscles to rely more on fat at marathon race pace, your glycogen stores last longer. In the marathon, that means that “the wall” moves closer and closer to the finish line and eventually disappears. (The concept of “the wall” is really a reflection of improper marathon preparation and pacing.) Later in this chapter, we’ll look at how to train to improve glycogen storage and fat utilization. In chapter 2, we’ll examine how your diet affects these vital processes.