Natural Selection

For years, Gordon Wright was a long-distance junkie. The 44-year-old enjoyed adventure racing and posted a 3:48 marathon, but he never got near the front of the pack. Then he did a 400-meter race on a whim, having not done speedwork in years, and won in 59.7 seconds, not far from the best in the nation for his age group. "I really am meant to run fast after all," he says. "That was a shock."

Wright is hardly alone. As he found out, success in some events comes more naturally than in others. In fact, few runners have the same potential to be outstanding at all distances. Some people have the innate gift of speed, while others are natural-born long-distance runners. In the end, your physiology, temperament and priorities will determine your ideal racing distance.

You may be surprised to find out where your true strengths lie. "Everyone thinks the marathon is the Holy Grail, when a lot of people should really be doing the 5-K," says Jason Karp, Ph.D., an exercise physiologist and coach in San Diego.

For better or worse, the physiology you're born with determines how well you'll perform your first time out, and how much improvement you'll be able to make in training. The good news is that with the appropriate training strategy, you can make the most of whatever you were born with.

So how do you determine whether you were meant to be a speed demon or a multiple marathoner? You could turn to pricey lab tests to measure factors like VO2 max and lactate threshold, but that probably would be overkill. Your running habits reveal plenty about what distances you're most suited to excel at now.

Read on to learn which physiological factors help shape your running identity. Then examine your training, racing history, and tendencies to find out which distances are the perfect fit for you. Finally, learn how to tweak your training routine and set realistic goals to better match your newfound specialty. Who knows? Like Gordon Wright, you might discover talents you didn't know you even possessed.

The Runner

The Speed Racer: These athletes are built to go fast-not long. Consequently, the 5-K and 10-K are ideal events to target.

The Middle-Distance Specialist: These people are best at sustaining a tough pace. So they're well suited to run strong 10-milers and half-marathons.

The Long-Hauler: These runners were really meant to go the distance. Though they may lack speed, their true calling is the marathon.

Natural Selection 1: Know your physiology

Each of these four qualities influences how fast and how far you can run—and which distance will suit you best.

Lactate threshold (LT) pace is the fastest pace that you can sustain for an extended period (roughly 30 minutes or more) before lactate—a by-product of the fuel burned during hard exercise—starts building up in the blood. Marathon winners often have high lactate thresholds, which help them hold a strong pace for a long time. With targeted training—maintaining a certain intensity over a distance—you can raise your lactate threshold.

Muscles are made of slow- and fast-twitch fibers. An elite marathoner's muscles might be 75 percent slow-twitch; an Olympic sprinter probably has a high proportion of fast-twitch. Most runners are born with a modest mix of both. You can't change the muscle composition you inherit, but you can train your muscles for speed or to sustain steady paces over long distances.

VO2 max measures the maximum amount of oxygen that can be consumed per minute while exercising. Runners with a naturally high VO2 max often find it easier to run faster because their hearts can deliver more oxygen to their muscles. There are many ways to boost VO2 max, including speedwork, which forces the heart to pump blood at a higher rate. Beginners can improve it by about 20 percent. In fit runners, it can only be fine-tuned.

"Running economy" measures the amount of oxygen you need to run any pace. It reflects how efficiently you run. Other physical factors impact running economy—if you're overweight or have a sloppy gait, for instance, you're going to need more oxygen than a leaner person with a cleaner stride. As you run more, and improve factors like VO2 max, weight, and biomechanics, you'll develop better running economy.

Natural Selection 2: Identify your true calling

Examine your own training and racing habits, and learn about what kind of running will give you the most satisfaction—and the best performances.

1) How many hours a week can you devote to training?

A. 2 to 3

B. 4 to 5

C. 6 or more

2) How would you describe the perfect training run?

A. It brings a surge of adrenaline and a feeling of power—it feels like kicking into high gear.

B. Running right at the edge of your abilities—not backing off from a difficult effort, but not pushing so much that you run out of steam.

C. It's getting into a meditative rhythm, where you can zone out or get absorbed in your thoughts, a conversation, or your surroundings.

3) If you could skip any workout each week, what would it be?

A. Any run that takes more than an hour. It's just too exhausting and boring.

B. Workouts that don't feel long enough or fast enough.

C. Any run where there's pressure to hold a fast pace. At that moment it feels too hard and ceases to be enjoyable.

4) When you're out on a group run, you stand out from the pack by:

A. Surging to the finish—no matter how hard the group has been running.

B. Managing to stick with the lead group, no matter how much they're pushing the pace.

C. Feeling pretty fresh at the end of a long run-no matter how far you've gone—even when other runners fall apart.

5) When you get injured, what typically precipitates the problem?

A. Total mileage. Overdoing it always seems to trigger some ailment—like plantar fasciitis or a screaming IT band.

B. A muscle pull, a tendon tweak or something that got twisted or torn while trying to keep up or dash to the finish.

C. No major injuries.

6) What's your philosophy when it comes to spending money on racing?

A. With all the races I do, it's hard to justify shelling out more than $30 on one event.

B. Spending $50 or so on a race is okay, as long as there aren't a lot of other costs for travel and logistics.

C. No one likes to part with hard-earned cash, but for a few big events each year, it's not a huge deal to spend $100.

7) When you're choosing a race, what matters most?

A. Convenience. Running shouldn't take time away from family, work, or other important commitments.

B. Getting a decent workout—and a good test—without having to deal with a lot of travel or race-day logistics.

C. It should feel like a big deal. Whether the race is a large, well-known event or is in a beautiful vacation spot, it should be something to circle on the calendar and look forward to, and it should feel like a reward for all the hard work of training.

8) What are the race distances where you had your best finishing times?

A. 5-K

B. 10-mile or half-marathon

C. Marathon

Answer Key (give yourself points as noted below)

1. A=2 B=4 C=6

2. A=1 B=2 C=3

3. A=1 B=2 C=3

4. A=1 B=2 C=0

5. A=1 B=2 C=0

6. A=2 B=4 C=6

7. A=2 B=4 C=6

8. A=2 B=4 C=6

Interpret your score

Your tally says a lot about you—about your strengths, the distances you were born to run, and your ideal training strategy.

11 to 18 points: You're a Speed Racer

You may not have thought about 5-Ks and 10-Ks since you first started running, but since you seem to be able to pick up speed with ease, that may be the place to stand out. On any weekend, you'll probably have your choice of races to test your mettle. And the best part is, you can put your all into training and racing without feeling like it compromises other parts of your life.

19 to 26 points: You're a Middle-Distance Specialist

It may feel like the world revolves around the marathon, but you may not have to go that far to experience greatness: 10-milers and half-marathons could be for you. Some brush off middle distances as "practice." But running them, you'll find out how far and how fast you can run. And you'll be part of a renaissance—as 13.1-milers become the most popular races, many have taken on the big-league feel of marathons, and they don't require as much money and time.

27 to 35 points: You're a Long-Hauler

While some people could never imagine "looking forward" to a few hours of running, you savor the long, slow distances that let you spend long stretches of time outside as you prepare for the big event. The marathon is for you. You may get left behind in a 5-K, but that shouldn't matter. For you, three miles is barely a warmup.