This story appears in the July 2018 issue of National Geographic magazine.

The race for the ages can be run only in our imagination: Usain Bolt vs. Jesse Owens.

Bolt is in his 21st-century lane, a smooth, slip-resistant rubber surface spread out for 100 meters, designed to quickly return energy to his legs as he races across it.

Then there’s Owens in his pre-World War II lane, an uneven bed of cinders, a soft surface that actually steals energy from his legs as he runs.

Bolt, the Jamaican sprinting legend who has eight Olympic gold medals and has held the world records in the men’s 100- and 200-meter sprints for nearly a decade, is wearing lightweight shoes made specifically for running on high-tech surfaces. For his entire competitive life, he has received the finest training the world has ever seen. He jets to competitions and has his own cook, who makes him lean, nutritious meals. Bolt also has been at his peak during the height of the steroids era in sports. He has never tested positive, but suspicion follows many top Olympic athletes of his time. Bolt had to forfeit a gold medal he won as part of a relay in the 2008 Olympics after a teammate tested positive.

View Images Jesse Owens won the 100-meter race at the 1936 Olympics in 10.3 seconds. Photograph by ULLSTEIN BILD VIA GETTY IMAGES

View Images A lightweight shoe like the one that Usain Bolt wore to set the world record in the 100-meter sprint in 2009 is shown on a piece of Mondotrack, similar to what he ran on that day in Berlin. The surface is designed to return energy to runners, making them faster. Photograph by MARK THIESSEN

View Images Usain Bolt, shown in 2016, holds the record, 9.58 seconds. With a better running surface and lightweight shoes, Owens could have been significantly closer to Bolt’s times. Photograph by KAI PFAFFENBACH, REUTERS

Owens, who won the 100 meters with a time of 10.3 seconds in the 1936 Olympics—one of four gold medals he claimed in Berlin—is wearing leather running shoes. Bolt is able to get a quick launch from state-of-the-art starting blocks, but Owens must dig his own “starting blocks” out of the cinders with a gardening trowel.

Owens grew up in a segregated America, with few of the perks of modern athletes. To get to Berlin, he and other U.S. athletes spent several days crossing the Atlantic on an ocean liner.

Bolt, who ran the 100 meters in a record 9.58 seconds in 2009 and retired last year, is still widely recognized as the world’s fastest man. But how much faster was he, really, than elite sprinters of previous generations like Owens?

Setting aside the questions about performance-enhancing drugs, how far have we come in our never ending quest to go faster, higher, and farther? And what are we learning about how technology and new training methods can help us push the limits of human performance?

A demonstration included in a 2014 Ted Talk given by sports journalist David Epstein showed that if Owens had run on the same surface as Bolt, Owens’s best time in the 100 meters (10.2 seconds)—accomplished shortly before the 1936 Olympics—could have been within one stride of Bolt’s performance in the 100 meters (9.77 seconds) at the 2013 World Championships.

In the eight decades since Owens’s historic victories, improvements in training, testing, technique, clothing, and equipment have helped athletes become better, faster, stronger, and more precise. But researchers believe we have not yet reached the limits of human possibility.

View Images Paralympian sprinter Jarryd Wallace’s bio­ mechanics are analyzed at the Southern Methodist University Locomotor Performance Laboratory in Dallas, Texas. “There was a lot I was doing wrong,” says Wallace, 28. The four-­time world record holder, whose lower right leg had to be amputated because of a muscle disorder, uses the lab’s analysis of his stride to run even faster. Photograph by ROBERT CLARK

The speed of innovation Male and female Runners have bested world records in the 100-meter dash over the past century. But the gear and the track infrastructure are what have changed most dramatically since the first competitions were run with the help of nails driven into the soles of dress shoes. 13.5 seconds 13.0 12.5 12.0 11.5 11.0 10.5 10.0 1910 10.6 seconds Donald Lippincott, U.S. July 6, 1912 1920 Duration of record 13.6 seconds Marie Mejzlíková II, Czechoslovakia 1930 August 5, 1922 10.2 Progression of 100-meter dash world record, Jesse Owens, U.S. 1940 June 20, 1936 1910-2018 KEY Women Men Manually timed record 1950 Electronically timed record 1960 1970 Separate records for manual and electronic times were kept from 1968 to 1977 as technology was improving. 1980 Lightning strikes thrice 10.49 1990 Florence Griffith-Joyner, U.S. Usain Bolt broke the men’s world record twice in 2008 and again in 2009, dropping it by 0.14 seconds, more than any man in the modern era. July 16, 1988 The unbeatable FloJo The top three women’s times are held by Florence Griffith-Joyner. She never tested positive for steroids, but her 1988 record—still unbroken today—shows how great performances can raise suspicion. 2000 9.72 9.69 9.58 Fastest time since Griffith-Joyner: 2010 Usain Bolt, Jamaica August 16, 2009 10.64 Usain Carmelita Jeter August September 20, 2009 Lighter shoes Better timekeeping Stronger starts Faster tracks Polyurethane tracks debuted at the 1968 Olympics. The tracks are bouncier and return energy to a runner; cinder tracks absorbed energy. Early racers dug holes into the tracks, which were usually laid with cinders. The introduction of solid starting blocks in the late 1920s led to new world records. The first running shoes were simply leather dress shoes, with nails to provide grip. Today’s shoes boast nylon, fiberglass, and single-use spikes. Early stopwatches measured only fifths of a second. It wasn’t until 1977 that fully digital timekeeping—to the hundredths of seconds— became mandatory. Jason Treat, NGM Staff; Meg Roosevelt Art: SErgio Ingravalle. icons: Álvaro Valiño. Sources: Adrien Marck, National Institute of Sport, Expertise and Performance, France; IAAF The speed of innovation Male and female Runners have bested world records in the 100-meter dash over the past century. But the gear and the track infrastructure are what have changed most dramatically since the first competitions were run with the help of nails driven into the soles of dress shoes. Stronger starts Early racers dug holes into the tracks, which were usually laid with cinders. The introduction of solid starting blocks in the late 1920s led to new world records. Lighter shoes The first running shoes were simply leather dress shoes, with nails to provide grip. Today’s shoes boast nylon, fiberglass, and single-use spikes. Faster tracks Polyurethane tracks debuted at the 1968 Olympics. The tracks are bouncier and return energy to a runner; cinder tracks absorbed energy. Better timekeeping Early stopwatches measured only fifths of a second. It wasn’t until 1977 that fully digital timekeeping—to the hundredths of seconds— became mandatory. Manually timed record Electronically timed record Duration of record WOMEN 13.5 sec. 13.0 12.5 12.0 11.5 11.0 10.5 1910 13.6 seconds Marie Mejzlíková II, Czechoslovakia 1920 August 5, 1922 1930 Stronger Starts 1940 1950 Lighter Shoes 1960 Faster Tracks 1970 1980 Better Timekeeping 1990 10.49 Florence Griffith-Joyner, U.S. July 16, 1988 The unbeatable FloJo The top three women’s times are held by Florence Griffith-Joyner. She never tested positive for ste- roids, but her 1988 record—still un- broken today—shows how great performances can raise suspicion. 2000 2010 MEN 10.5 10.25 10.0 9.75 1910 10.6 seconds Donald Lippincott, U.S. July 6, 1912 1920 1930 Stronger Starts 10.2 Jesse Owens, U.S. June 20, 1936 1940 1950 Lighter Shoes 1960 1970 Faster Tracks 1980 Better Timekeeping 1990 2000 9.72 2010 9.69 9.58 Usain Bolt, Jamaica August 16, 2009 Jason Treat, NGM Staff; Meg Roosevelt Art: SErgio Ingravalle. icons: Álvaro Valiño. Sources: Adrien Marck, National Institute of Sport, Expertise and Performance, France; IAAF

Peter Weyand, who runs the Locomotor Performance Laboratory at Southern Methodist University in Dallas, Texas, and is one of the world’s leading experts on the biomechanics of sprinting, says that the potential for significant improvement in the 100- and 200-meter sprints and in marathons is not out of the question. His lab uses high-speed video analysis to study sprinters’ techniques, looking for ways to make them more efficient—and faster. Weyand is part of a team led by United Kingdom sports scientist Yannis Pitsiladis that’s focused on breaking the two-hour marathon barrier. (A similar Nike effort fell short in 2017.) To help athletes shatter records, researchers are focusing on such key areas as physiology, nutrition, biomechanics, medical support, real-time monitoring, and coaching. This kind of scientific knowledge “allows performance to be improved,” Weyand said.

To help athletes legally push the limits of performance, scientists are experimenting with new techniques and equipment, measuring performance in novel ways, and monitoring athletes’ nutrition and physical and mental health.

That amazing pass by a player on your favorite soccer team? It might have gotten its start with a training machine called the Footbonaut, which fires soccer balls at a player at varying speeds and rhythms, forcing the player to control the ball and send it to an open slot in the machine.

View Images CJ Cummings’s body type and his technique—he pulls the bar faster than other lifters and maintains this speed as the lift progresses—separate him from the competition. Bob LeFavi, while head of health sciences and kinesiology at Georgia Southern University in Savannah, analyzed Cummings’s biomechanics. Researchers found that a “perfect storm” of attributes—strength, speed, body structure, and technique—all contribute to his success. Still a teenager, Cummings should reach his full potential in his mid to late 20s, LeFavi says. Photograph by MARK THIESSEN

View Images Record-breaking weightlifter Cummings, 18, defended his Youth World Championship in 2017 and broke his own world record for the “clean and jerk” by lifting 407 pounds. Photograph by Mark Thiessen

That curveball your favorite baseball pitcher threw? Fifty years ago, coaches would simply watch a pitcher to see how he was throwing. Now coaching is a mixture of reviewing video and statistics on big-screen TVs, cell phones, tablets, and laptop computers—with old-fashioned intuition thrown in. And coaches can instantly measure the speed of a pitch.

This conversation about human performance comes with a strong note of caution. Can we believe what we’re seeing? In 1988 we marveled at the world record 100-meter dash of Canada’s Ben Johnson—until he tested positive for using a performance-enhancing drug, was stripped of his gold medal, and was sent home from the Summer Olympics in Seoul. The steroids era in sports is going strong 30 years later: U.S. cyclist Lance Armstrong, U.S. track star Marion Jones, Russia’s Olympic delegation—the list of violators goes on.

But let’s focus on the good in sports technology, which has upended training for paralympic athletes as well.

Visually impaired skier Danelle Umstead, a three-time Paralympian and three-time bronze medalist in a sport where athletes can reach speeds of 70 miles an hour, has trained in a wind tunnel that allowed her to work on aerodynamics with a sight guide. During races she follows her partner through the course as they communicate via headsets. Training in the tunnel helped her tweak her technique to go faster.

Meanwhile, coaches and athletes are challenging long-held assumptions about training.

View Images Olympic hopeful Michael Andrew trains with his father and coach, Peter, in a pool at their home in Lawrence, Kansas. He swims short, fast distances in a program that challenges traditional training methods. Photograph by MARK THIESSEN

View Images Swim prodigy Andrew’s training program of high-intensity distances conditions his mind and muscles to swim at race pace. Andrew, 19, holds 22 USA Swimming records. Photograph by MARK THIESSEN

Michael Andrew, 19, has broken the most national age-group swim records in USA Swimming history and holds 22 national records. He and his father-coach, Peter, swear by a nontraditional training method called Ultra-Short Race-Pace Training, or USRPT. Andrew swims at short high-speed distances, conditioning his mind and body to constantly swim at race pace. Traditionally, elite swimmers have built endurance through workouts that involve a slower pace with more yardage. The much debated approach has helped make Andrew an Olympic hopeful for 2020 and is gaining traction among top swim coaches in the U.S. and elsewhere.

“Everything we do is science-based; there is data to back up what we’re doing in the pool,” Andrew says. “Our brain and our body will code these movements like a computer would. It doesn’t make sense to train slowly when you’re trying to swim fast.”

American distance swimmer Katie Ledecky, who recently announced that she is leaving the Stanford University team to become a professional swimmer, has a more traditional training method. But Ledecky, 21, has used sports science to become one of the best women’s freestylers in the world. The five-time Olympic gold medalist, who set two world records at the 2016 Olympics in Rio de Janeiro, Brazil, eagerly digests readouts about her nutrition and blood work, and studies videos of her workouts and races, looking for ways to improve her arm and hand movements. Ledecky’s success often is attributed to her work ethic; her real secret could be that she has one of the most efficient strokes in swimming.

That wouldn’t have mattered, though, if she had not been willing to work hard, says Bruce Gemmell, who coached Ledecky to the 2016 Olympics. In the three years before the Rio Olympics, Ledecky’s weekly workload was usually 60,000 to 65,000 yards, spread over nine practices in six days. “I give speeches about coaching Katie,” Gemmell says. “One day, I’m tempted to put up just one slide saying, ‘Katie works her ass off, and she’s tough as nails,’ and then say: ‘Any questions?’ ”

Two things during those practices made a difference for Ledecky in Rio. She wanted to pay attention to the start of her races—how she dived into the pool. For sprinters, this obsession would make sense. Every 10th of a second matters in races that are decided by hundredths of a second.

But Ledecky is a distance swimmer, known for finishing far ahead of her competitors. “She studied a video of her starts, hoping to gain a 10th of a second,” Gemmell says. Ledecky’s second practice obsession involved the finish of the 200-meter freestyle. As she would finish a series of laps during practice, she would suddenly pick up the tempo at the end, in the last 15 meters or so, increasing her kick furiously, Gemmell says.

View Images Paralympic visually impaired skier Danelle Umstead, 46, tests her aerodynamics in a wind tunnel to learn better techniques for drafting behind her sight guide (not shown), who skis in front of her. Paralympic skiers can reach speeds of 70 miles an hour. Photograph by MARK THIESSEN

“In the midst of this most mundane work, she did that, two to three times a week, for 15 minutes to a half hour, finishing every rep that way.”

Move ahead to the 200 freestyle in Rio. Because it was her shortest individual race, it would be her closest. She couldn’t put other swimmers away so decisively in such a short race, just four lengths of the pool. She knew the finish would matter most. Sure enough, as swimmers neared the finish in the 200-meter finals, Ledecky’s top rival, Sarah Sjostrom of Sweden, closed fast and drew even with Ledecky with 15 meters to go. It looked like Sjostrom had the momentum and would win.

But Ledecky wouldn’t lose. Why? It was all that practice for the end of the race. “When Sarah pulled up even, I thought, I’ve seen Katie finish that race more than a thousand times. She’s going to get her hand to the wall first.”

And she did. “No wonder she can do that in the pressure cooker at Rio,” Gemmell says. “She knew exactly what she was doing in practice, over and over again.”

Ledecky’s overall performance in Rio was one for the history books. But she and Gemmell had foretold it three years earlier, after she broke the 800-meter freestyle world record. They were musing about how much faster she wanted to go in the 800- and 400-meter freestyles in 2016, and Ledecky wrote down her goals on a Styrofoam float she used in practice and carried with her to meets around the world. Her new world record for the 800 freestyle was 8:13.86. Ledecky’s goal? 8:05. It seemed crazy: Breaking her own world record would be one thing, but by almost nine seconds?

During the next three years, Ledecky kept lowering her world record in the 800 freestyle. By early 2016 she had dropped her record to 8:06.68. In Rio she crushed the field and set another new world record: 8:04.79.

View Images Runners from Iten practice together. Distance running is a proud tradition in Kenya, where many of the best runners take advantage of the region’s high altitude and challenging terrain. Kenyan men have nine of the 10 fastest times in the marathon; four of the 10 fastest women’s times were run by Kenyans. Photograph by NICHOLE SOBECKI

View Images Acclaimed distance runner Nancy Kiprop, 39, dances with students at the school she founded near Iten, a tiny corner of western Kenya where many of the world’s fastest distance runners train. The local government allowed her to establish the school, which she named in honor of her father. Kiprop subsidizes the children’s school fees with income from her shoe sponsorships and race earnings. Photograph by NICHOLE SOBECKI

This made Gemmell wonder: “What if we had said eight minutes flat? We don’t know where the limit is. We set goals that were unheard of three years before Rio. Once Katie reached them, I couldn’t help but wonder in the back of my mind: Why didn’t we set them faster?”

Ledecky and other top athletes today have the advantage of the march of time in their sport. Look at a photo of swimmer Mark Spitz from the 1972 Olympics, and you’ll see the difference: no goggles, no cap, no state-of-the-art, water-repelling swimsuit. He even had a mustache. Pools then didn’t have the improved gutter systems and wave-reducing lane ropes that competition pools use now to absorb much of the splash from nearby swimmers. It all slowed Spitz down, but we didn’t know that then. He still won seven gold medals in 1972.

Health science has played a big part in the lives of generations of swimmers since. Gemmell tells a story about a minor ankle injury Ledecky suffered while practicing at the U.S. Olympic Training Center in late spring 2016, just a few months before Rio.

“Within two hours, we had the opinions of two doctors, we had an ultrasound, we had a physical therapist, a strength and conditioning coach, a swim coach—that was me—and like three other people, who had already reviewed the data, consulted with each other, and formulated a plan.”

Alan Ashley, the U.S. Olympic Committee’s chief of sport performance, says the key to breaking performance barriers is to “keep athletes healthy. If they stay healthy, everything else falls into place.”

In the late 1960s, figure skater Audrey King Weisiger finished third in the U.S. women’s novice division one year and third in the junior division the next. She learned to jump high and quickly—not because it was the right way to do it but because she was training on a small rink in Falls Church, Virginia, that was one-third the size of a regular rink. “If I went the distance, I would have smashed into the wall,” she says.

Coming up in the sport about the same time as 1976 Olympic champion Dorothy Hamill, Weisiger was surrounded by young women doing double-revolution jumps, so she did only doubles in competition, although she did successfully do triple jumps in practice. Unlike today’s skaters, she didn’t train with weights, she didn’t take Pilates, and she wasn’t concerned about nutrition. “We did have ballet,” she recalls.

Move ahead to the late 1980s and 1990s. Weisiger, by then a top-ranked international coach, taught her pupil Michael Weiss how to land doubles and triples—and finally, quadruple jumps. He was the first American to attempt a quad toe loop at the U.S. national championship in 1997. Weiss went on to compete in two Olympic Games and won three national titles and two world championship bronze medals.

Unlike Nathan Chen, a 2018 Olympian whose slim body and tiny waist and hips help him rotate quickly in the air, Weiss had a muscular build, so he relied on upper-body strength to power himself through the air.

View Images Ledecky—a world-record-breaking athlete who won four gold medals and one silver at the 2016 Olympics—has the latest scientific and technological resources and training available. The U.S. distance swimmer studies readouts about her nutrition and blood work, reviews video of her technique. Ultimately, her success is attributed to grit, hard work, and a near perfect stroke. Photograph by JOHN HUET

View Images Swimmer Ledecky is known for her tough work ethic. She also relies on sports science to improve performance and is equipped with the latest innovative gear. Photograph by JOHN HUET

Weisiger would record Weiss’s jumps on what would now be a vintage video camera, put the VHS tape into a VCR hooked to a TV monitor, and then wheel the TV onto the ice so she and Weiss could watch it together. Then they’d get back to work.

“We could see it, but we had no way yet to measure it,” Weisiger recalls with a laugh. “I’d say, ‘I think it’s high enough,’ and off we’d go, trying it again.”

Today, chatting over dinner at a restaurant, Weisiger touches her iPhone and opens an app called Vert. “If I put a belt with a sensor on you, and you jumped, I could tell you with my phone how high you jumped, which would be the beginning of our conversation about trying a quad,” she says.

Later Weisiger sent me a dozen text messages showing photos of a skater’s first, second, third, and fourth revolution of a quad jump, with a timer under them that showed the process lasted little more than half a second—0.68 of a second to be precise—from takeoff to touchdown.

Trying these difficult jumps can be dangerous. Crashing on the hard ice over and over again can cause career-ending injuries. So for several decades, figure skating coaches have been able to strap a skater into a harness at the end of what looks like an elaborate fishing pole. In 50 years Weisiger had progressed from learning organically how to land high, tightly spiraled jumps because otherwise she would run into a wall at the rink, to using her phone to tell how high and long a skater was in the air while doing a quad.

Advances in technology give coaches the ability to help their skaters understand the physics of these jumps, but something more is at work here, Weisiger says.

View Images Cyclist Lorenzo Sinteur undergoes a maximum exercise test at the Centre for Human Drug Research in Leiden, Netherlands. The center performed a rare, double-blind, randomized, placebo-controlled trial on the effects of erythropoietin, or EPO, on cycling performance. Analysts found that the blood booster at the heart of the Lance Armstrong doping scandal does not improve actual cycling performance. Photograph by David Burnett

“Why wasn’t Dorothy Hamill doing triple jumps?” she asks. “She didn’t have to. Once women started to try triples, everyone had to do them. It’s like anything else: Competition pushes you along.”

In February in Pyeongchang, South Korea, women’s Olympic figure skating champion Alina Zagitova of Russia landed seven triple jumps in her free skate. Chen became the first man to attempt and land six quads in his free skate, finishing fifth overall after a poor short program.

Sometimes the march of progress in sports is simply the result of an athlete’s competitive fire.

To my unaided eye, a jump at the 1991 world track and field championships in Tokyo’s National Stadium looked monstrous. I had been watching the best long jumpers in the world for more than an hour, and American Mike Powell’s jump clearly was different. Technology would confirm what my eyes were telling me, but I already knew. The most legendary and seemingly untouchable individual record in Olympic sports, which had stood for a stunning 23 years, had just been broken.

as good as it gets? World’s 10 best performances by year 1921-2016 Athletic achievements improved for decades, in part because of new technology and the use of performance-enhancing steroids. With athletes under increased scrutiny, world records are still getting broken—but more incrementally. This could suggest that we are pushing the limits of our athletic potential. Men Women 100-meter dash Marathon Shot put Annual average Individual performance 1968 First Olympic drug testing (narcotics and amphetamines) 1976 First Olympic steroid testing 1987 Random drug testing instituted 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Current world record Darker colors indicate overlapping performances Percentage achieved of current world record 80% of current world record The steroid era The introduction of ste- roids affected women’s records more than men’s, perhaps because anabolic steroids increase testos- terone, which is naturally occurring in only small amounts in women. 60% Dominant Kenyans Over the past two decades, Kenyan men (outlined above) have dominated the marathon, posting nearly 60 percent of each year’s top 10 fastest times. Concentrated power The war effect Leaderboards of less popular sports like shot put are dominated by a few individuals, such as New Zealand’s Valerie Adams (outlined above). Athletic records were rare during World War II. Many elite athletes were called to military duty, and most international competitions were canceled. 40% Women’s marathon data available only from 1980 Jason Treat, NGM Staff; Meg Roosevelt Sources: Adrien Marck, National Institute of Sport, Expertise and Performance, France; IAAF as good as it gets? Athletic achievements improved for decades, in part because of new tech- nology and the use of performance- enhancing steroids. With athletes under increased scrutiny, world records are still getting broken—but more incrementally. This could suggest that we are pushing the limits of our athletic potential. World’s 10 best performances by year 1921-2016 Men Women 100-meter dash Marathon Shot put Annual average current world record Percentage achieved of current world record Current world record 60% 80% 40% 1920 1930 1940 1950 1960 1968 First Olympic drug testing (narcotics and amphetamines) 1970 1976 First Olympic steroid testing 1980 1987 Random drug testing instituted 1990 The steroid era The introduction of ste- roids affected women’s records more than men’s, perhaps because anabolic steroids increase testos- terone, which is naturally occurring in only small amounts in women. 2000 2010 80% 100% Women’s marathon data available only from 1980 Jason Treat, NGM Staff; Meg Roosevelt Sources: Adrien Marck, National Institute of Sport, Expertise and Performance, France; IAAF

My fascination with the advancement of sports performance didn’t start on that warm, humid August evening, but it certainly got quite a boost. Two inches here and there might not seem like much in our daily lives, but that was almost exactly the distance between Bob Beamon’s landmark leap of 29 feet 2.39 inches, set at the 1968 Olympics in Mexico City, and Powell’s 29-foot, 4.36-inch jump that night in Tokyo.

All these years later, that moment fascinates me. Why? With everything science and computers and great minds can devise to help humans perform faster, higher, and stronger—and because a sport like track and field has progressed from cinder tracks to synthetic surfaces, from rudimentary footwear to famous shoe companies trying to outdo one another—record-breaking progress still came down to the work of one human being. Sports is now filled with scientists, coaches, and athletes who measure progress through analytics. But that night, the march of human performance had a face and a name: Mike Powell.

The story behind making sports history sometimes really isn’t that momentous. In this case, one athlete just became angry with the success of another and wanted to beat him.

I called Powell recently in Southern California to ask him to relive that moment. There was no particular science to that night, he told me.

Powell said he broke the record because he was pushed by a competitor: The great Carl Lewis, widely considered the best long jumper ever, was also in the field. Lewis never broke the world record himself. Unwittingly, though, he helped Powell do it. “I love Carl now, but back then I hated him,” Powell said. “So when we competed, he brought my energy level way up.”

View Images Research volunteer Yunna Sinskey walks on a treadmill mounted on a motion base inside a 360-degree virtual reality dome, which includes wall-mounted cameras and projectors at MIT Lincoln Laboratory. Reflective markers are placed on her body, allowing the 18 cameras mounted in the dome to capture her movements for a study on improved diagnosis and treatment of mild traumatic brain injury. Tracking movement patterns can also help diagnose injuries in athletes. Photograph by DAVID BURNETT

Right before Powell uncorked the record jump, Lewis leaped farther than anyone ever had, beating Beamon by a quarter inch. But the wind was blowing too hard at his back, so it didn’t count.

Powell can’t get the image out of his head nearly three decades later. “He ran past me, pumping his fist. That got me mad. It made it real personal. I had always been the skinny guy, the one picked on. It was happening again, right there. But I could do something about it this time. My body just took over and did what I needed to do.” Powell’s amazing jump is still the world record. “Carl raised the bar so high,” Powell said. “I knew I had to break a world record just to beat him.”

That’s the school-yard view of human performance—and a testament to the mind’s ability.

“I don’t think we have really tapped into the power of the brain,” says Gemmell, Ledecky’s Olympic coach. “That’s the next frontier over the next 30 years: how we train the brain like the body. That’s where the breakthroughs are going to come next.”