How a Marathon Works

The marathon's origins stretch all the way back to ancient Greece. The late fifth century B.C. was a tumultuous time for Athens. Neighboring Persians hoped to overtake the city, and they had the military power to do it, outnumbering Athenians nearly five to one [source: Galloway].

The Greeks relied on fleet-footed messengers during wartime. These messengers covered the rocky and mountainous terrain and served as informational diplomats. Jeff Galloway explains that "they were expected to not only deliver the news but to also interpret it, emphasize key points, and return with a reply, including a description of the facial expression and emotion of the recipient" [source: Galloway].

Phidippides was the Athenian army's messenger. Around 490 B.C., he was sent from the army's stronghold at Marathon to Sparta, where he asked for the Spartans' help fighting off the Persians. The trek likely took him a day and a half -- and the Spartans' answer had been a disappointing "no." Phidippides returned to Marathon a day and a half later.

The Athenians eventually outmaneuvered the Persians. Celebration was short-lived: The army had to spread the word to the city. The Athenians were planning to burn their city to elude victorious marauders. Once again, Phidippides hit the ground running. According to legend, the exhausted runner managed to make it to his destination only to gasp out "Nike" (Greek for "victory") before he collapsed and died [source: Galloway].

In 1896, the year of the first modern Olympic Games, the marathon was recreated as an athletic event. Pierre de Coubertin was the mastermind behind the games, but it was co-organizer Michel Breal who proposed including a race commemorating Phidippides' legendary trek. The race -- dubbed "marathon" after the messenger's starting point -- was nearly 25 miles (40.2 kilometers) long.

Enthused race supporters called it the ultimate homage to the ancient Greeks, whose minds had conceived of the Olympics. But detractors argued that the race was unsafe: The weather would be too hot and the distance far too long for man to survive it.

Nonetheless, the marathon remained on the itinerary -- and the Greeks were favored to win. Their marathon team was carefully selected through trial races over the marathon course. A few sources give credence to detractors' warnings by claiming that three men died during these trials [source: Lovett]. The fastest time among these trial finishers was around 3:18 (Charilaos Vasilakos); and a second trial produced a finisher who clocked 3:11:27 (Mr. Lavrentis -- first name unknown). The Greeks finally chose 13 men for their team -- which made up the bulk of the 17 competitors.

Spiridon Louis (who placed only fifth in the second set of trials) took first place in the race with a time of 2:28:50 [source: Lovett]. He even stopped halfway through the race at Pikermi to have a glass of wine. Vasilakos came in second place.

In 1908, when London hosted the Olympic Games, the marathon track was extended to its current 26.2 miles at the behest of King Edward VII's wife, Alexandra, who asked that the course start by the palace. Her request was obliged, adding 1.2 miles to the already trepid distance.

A course of 26.2 miles is no simple feat. Next, we'll discuss some factors to consider when deliberating the distance.

If you've ever cheered on the sidelines of a marathon course or heard a friend recount the victorious feeling of crossing the finish line, you know the kind of well-won bragging rights that come with the marathon. It's not hard to be inspired by this legendary distance -- and it's not uncommon to be intimidated by it.

When you think of a marathoner, do you imagine the stick-thin man in teeny-tiny shorts leading the pack? He represents only a fraction of the marathoning demographic.

Until the 1970s, the kind of thought that influenced the marathon detractors in the Olympics kept hold in the popular imagination. People assumed that the marathon was a dangerous feat and that only the most elite athletes could participate. Most runners raced to win; very few -- if any -- ran for fun or good health [source: Bloch]. When was the turning point?

Marathoner Gordon Bakoulis Bloch attributes the shifting attitudes to two factors: the American marathon victory at the 1972 Olympic Games (Frank Shorter took the gold in Munich) and the "fitness revolution" that was gathering force [source: Bloch]. While many opted for leotards, leg warmers and Jane Fonda's aerobic workouts, others discovered the economic practicality of running. As Boston University Athletic Enhancement Center (BUAEC) chairman Noel Vigue, M.Ed., explains, running is an inexpensive and effective way to stay in shape. Its benefits include:

[source: Boston University]

As more people took up running for health and sport, road racing became popular. These races spoke to people's competitive natures and offered an opportunity for runners to socialize with one another. While many runners work up to the 26.2 mile (42.195 km) distance from more modest distances like 5ks and 10ks, others take the all-or-nothing approach to road racing and begin with the ultimate distance: the marathon.

In the 1990s, marathons boomed in popularity. From 1991 to 1992 alone, marathon finishers increased from 9,000 to 9,200 [source: Bloch]. According to Running USA, the number of runners in the largest half-marathon (OneAmerica 500 Mini) and marathon (ING New York City) in 2007 numbered 29,209 and 38,607, respectively [source: Running USA].

Who's running these races? The majority of these runners are men, but female participation is increasing steadily. Katherine Switzer, the first official female Boston Marathon participant, explains in her book "Marathon Woman" that perception of age plays into the number of women runners -- 40 is no longer considered "old," and women in their 50s and 60s are embracing physical challenges. She adds that women today are outgrowing the cultural perspective that athleticism is "unladylike" [source: Young]. While most races require participants to be more than 18 years of age or to have a guardian-signed waiver, Running USA reports that over the past 15 years, the percentage of runners under 20 years old has increased from 1 to 1.8 percent. Another surprising statistic? Road Running Information Center shows that most long-distance runners are college educated -- anywhere from 74 to 93 percent of them [source: Running USA].

In addition to strengthening your body, the marathon also builds another important muscle: your brain. The marathoner must always think ahead. From planning training schedules to finding thoughts to occupy your mind on long runs of 15 miles or more, you must find ways to overcome burnout and boredom and listen to your body.

We'll talk about some training strategies next.

If you were expecting a how-to section here, brace yourself: There's no one way to train for a marathon. And even if there were, we couldn't cover all your training bases in one measly section! Training for a marathon takes months of preparation and hard work.

Training regimens vary widely across the board. It's easy to get carried away by the different schools of thought in running, the number of running shoes on the market, the many diets that promise to complement your regimen and fellow runners who offer unsolicited advice about the sport.

At its most basic level, marathon training is preparing your body to run 26.2 miles. In addition to the workouts your training regimen prescribes, this preparation usually encompasses:

The many sources available for training can be helpful but confusing, too. In your search for the ideal regimen, it's helpful to consider your goals for the race. Do you want to run the entire distance or walk parts of it? Finish in under three hours -- first in your division -- or even first overall? Or do you simply want to finish? Time isn't the only factor to consider. If you're a social runner, you may scope out local running groups in your city. Even if you're a lone wolf, the support of fellow runners may get you out of bed and on the pavement when your training hits a rough patch. What's more, they'll hold you accountable for training.

You can hold yourself accountable and measure your progress through a training journal. This vital training tool is a place to record your daily mileage or time, routes, body weight or other changes in physiology and notes about weather, stress level or schedule that may have affected your training.

While the smooth-worn rubber soles of your running shoes and your sharply defined calves attest to the miles of training you've put in, there are some internal changes that speak to your hard work, too. Next, let's take a look at the physiology behind marathoning.

You can appreciate what you're putting your body through if we take a brief look inside it. What's more, it's easier to listen to your body when you understand what it's doing.

A quick anatomy lesson about marathon muscles: There are two groups of muscles that are important to your training, slow twitch and fast twitch. Slow twitch muscles are the most important of all. These muscles are good for endurance events because the fibers contract (get tense and tighten, thereby becoming smaller) slowly. Fast twitch muscles contract much faster, which makes them ideal for speed events, like sprinting. Elite marathoners might have a physiological edge over other runners. Some studies have shown that they have a significantly larger proportion of slow twitch to fast twitch muscles [source: BBC]. But, you can train your muscles to work for you -- no matter your proportions. You develop your slow twitch muscles through endurance training, like your weekly long runs. And you build fast twitch muscles through your speedwork.

Nearly all training programs advocate days of rest in your regimen. On a rest day, you abstain from running to give your muscles time to heal. When you tax muscles, they rip and tear. Don't worry -- they're designed to do this. When your muscles repair these tiny tears, they grow back even stronger than before. If you're feeling particularly sore after a grueling workout, your body is probably giving you a cue to take it easy.

In addition to getting your muscles ready for the run, you're also prepping your lungs for the race. Running is an aerobic exercise -- it relies on your body's ability to use oxygen efficiently. When you're running, your muscles are working overtime. They need oxygen to support them. You supply this to them by simply breathing; your body does the hard work by sending the oxygen to your heart and lungs, where it's transported by the circulatory system to your muscles [source: Bloch]. But it takes time to gain aerobic fitness -- and if you don't start training slowly or at your level, you'll be sucking wind.

So how do you know if your body is working hard enough or too hard? You can gauge your activity level by using a heart rate monitor. Gordon Bakoulis Bloch offers a formula for determining your ideal training heart rate (beats per minute or BPM) when running: 220 (-) your age (x) 0.6 and 0.9 [source: Bloch]. For instance, a 25-year-old's BPM would fall into a range between 117 and 175.5.

But if you don't have a heart rate monitor, you can use the talk test. In your ideal training zone, you should be able to speak. If you're working too intensely, you won't be able to eke out more than a couple of words. And if you're not working hard enough, you'll find that you can talk -- and even sing.

You're training not only your body but also your mind for the race. Many sports advocate the practice of visualization before the big event. Visualization refers to imagining yourself in the act of the event and accomplishing your goal. Jeff Galloway advocates a practice called positive brainwashing. You can make yourself think positively by repeating "magic words" to spur yourself onward. The words Jeff recommends ("relax, power and glide") address complications that runners face on the course [source: Galloway].

Even if you've trained properly, you can't anticipate all the difficulties of the race. In the next section, we'll learn about running the marathon.

Plenty of runners climb on their treadmills or circumvent their neighborhoods every day to build mileage. Some of them will run for good health, some for fun and some because their dogs demand the exercise. But most runners find that racing is where their hard work pays off. You don't have to finish first -- or even 31st -- to feel like a winner when you cross the finish line.

One factor that may attribute to this is runner's high. There comes a point in a long run when everything just clicks: breathing is steady, the stride is even and easy and the body feels just amazing. Runners have referred to this state of euphoria as runner's high. Jesse Pittsley, Ph.D., and president of the American Society for Exercise Physiologists, describes the sensation as "a reduced state of discomfort or pain, and even a loss of time." So is runner's high real? Yes and no. Scientists once thought it came from exercise-released endorphins, but they posit now that it's got more to do with repetition, rhythm and duration [source: WebMD].

An experiment at the Georgia Institute of Technology and University of California, Irvine, found that long-duration exercise produced anadamide, which is a cannabinoid. While the human body makes this molecule naturally, it elicits a feeling not unlike those caused by THC, a chemical found in marijuana. Does the body make itself high? Perhaps. Dr. Arne Dietrich hypothesizes that the body makes these chemicals to counter the sometimes painful effects of exercise [source: CNN].

At the opposite end of the spectrum is the feared phenomenon of hitting the wall. When runners hit the wall -- usually around mile 18 or 20 in the course -- their bodies simply stop functioning. This extreme fatigue can incapacitate runners to different extremes. Some may find that they can limp to the finish line while others have to be carried off the course by medics. So what causes a runner to hit the wall?

It boils down to stored energy: glycogen and fatty acids. Glycogen is your body's biggest source of fuel for running the marathon. Your body tucks it away in the muscles, and when it needs the energy, converts it into glucose -- rapid-release sugar [source: BBC]. The primary reason that marathoners carbo-load (or eat lots of carbohydrates) before the race is to store up glycogen. You can also build glycogen reserves through training. Unlike glycogen, fatty acids are released very slowly. The body stashes them in the tissues and can draw on them in case of emergency. When you're at the wall, this is an emergency -- but your body can't always draw on the reserves fast enough. For those runners you see limping across the finish line, you can assume their bodies have tapped into fatty acid reserves; for those who don't make it, all reserves are likely depleted.

In addition to training (which you can see is preparatory and precautionary), there are other measures you can take while running the marathon to stay sharp and focused. Most importantly, you should hydrate. Most marathons will offer water and electrolyte-infused energy drinks at nearly every mile marker. Others will have food stations on the course with items like bananas that help you rebuild your glycogen stores; some runners will bring energy bars or energy gel packs to replenish their stores.

Listen to your body during the race -- and distinguish between your mind's will to finish and your body's pleas to stop. The thrill of crossing the finish line will be short-lived if you're crippled with pain for weeks afterward. We'll talk more about pain and your health in the next section.

Being able to run 26.2 miles means you're in optimal health, right? Not exactly. We've already identified some of the benefits of long-distance, endurance running, but now we'll delve into the darker side of the marathon.

Marathoners who die training or on the race course usually make headlines because these tragedies seem so unusual -- who could be in better health and less likely to die than a runner? At the age of 52, Jim Fixx, a celebrated runner who wrote "The Complete Book of Running," died in 1984 of arteriosclerosis [source: New York Times]. In this condition, the arteries' walls become clogged and thickened, causing less blood to flow through them. In 2007, 28-year-old Ryan Shay died while competing in the U.S. Olympic marathon trials. His death was attributed to an irregular heartbeat [source: AP].

It's pretty obvious that running affects the heart, but did you know that running can actually increase the size of the heart? Hearts can enlarge when an athlete is engaged in serious physical training. The body compensates for the increased amount of blood it needs to pump throughout the body by increasing the size of the organ where it originates. Enlarged hearts can lead to arrhythmia, or irregular heartbeat, which can, in turn, lead to heart failure. Diagnosis of this condition is tricky -- it's difficult to tell whether an athlete's enlarged heart and its thicker walls are exercise-induced or a sign of hereditary disease [source: Allison].

Another rare but potentially fatal condition is hyponatremia. This occurs when runners drink too much water while racing. Your body loses sodium when you sweat, and drinking too much water depletes your sodium even further because you release it through urination. If you take in too much fluid, your muscles can't coordinate the proper electrical transmissions with your heart, resulting in a sudden cardiac arrest (SCA) [source: Galloway interview]. To avoid hyponatremia, it's best to limit your fluid intake to no more than 13 to 27 ounces per hour [source: Galloway interview].

Some marathoners assume that their fitness level absolves them from health problems. This simply isn't the case. Medical examinations can pinpoint the kinds of heart irregularities and risk factors that kill and injure runners. But there are ways to reduce your risk factors, too. Don't assume that you can eat or drink whatever you want because running will burn off the calories -- diets rich in saturated fat can lead to heart problems further down the road.

In addition to these life-threatening aspects of the sport, there are other sports injuries to beware of. Most of these are overuse or overtraining injuries that can be prevented by tapering your training -- that is, resting properly and cutting back on your mileage. These are a few of the most common infirmities:

[source: Bloch]

While you should approach the sport with caution, you should also have fun running. Specialized training programs can help you achieve this goal. Running guru Jeff Galloway says his biggest running accomplishment is staying injury-free for 29 years. His philosophy? "I am personally against injuries, death and puking" [source: Galloway interview].

For more information on marathons and related topics, visit the links on the next page.