NOW YOU SEE HIM, NOW YOU’RE NOT SURE WHAT YOU’RE SEEING
In Luke Dittrich’s July 22, 2012 Esquire article “A Lament for Tyson Gay,” he explains it this way:
By almost every criterion, Gay is the better runner. He trains harder, gets off the blocks faster, has superior form. Even in purely physical terms, Gay has the sort of dense, muscular, compact body that was long considered the apotheosis of the human sprinter before that tall, lazy, gangly showboat [Bolt] loped out of Jamaica and changed everything. The only area in which Gay falls short is the most important one…
And so the debate begins. Usain Bolt is the most celebrated sprinter in history. At the start of the 2016 Rio Olympics, he is poised to achieve an unprecedented “triple-triple”: gold in the 100m, 200m and 4x100m for the third straight time. Over the course of these past 8 years, he has dominated the sport of track & field with unparalleled aplomb and celebrity. On his way to two world records (9.58/100m and 19.19/200m), Bolt has beguiled, bewildered and charmed his way to the top. Unlike any other athlete of this era (with appreciation for LeBron, Phelps, Serena etc.), the fascination with his prowess is unmatched. Although under such circumspection, Bolt’s talents still remain a mystery. Everyone from sports announcers to mechanical engineers to even Bolt himself, are still trying to piece together a consistent, air-tight explanation for how the 6’5″ sprinter from Jamaica hits top speeds of 27.79 mph.
Much of what we learn from kinesiological science is peripheral – results spawned from long-held beliefs, data that has been culled and massaged to support preconceived notions about human movement and performance. In an article on biomedical research published July 2016 in the Journal of the American Medical Association (“What Happens When Underperforming Big Ideas In Research Become Entrenched?”, Michael J. Joyner, MD; Nigel Paneth, MD, MPH; John P. A. Ioannidis, MD, DSc), the authors make an interesting observation: “When claims about high-profile, dominant “big ideas” are viewed against their mediocre benefits, it seems that [one] basic course(s) of action…is to reevaluate and reset the current focus…. In the current environment, scientists are pigeonholed in a narrow discipline and are penalized [if] they exit their specific niche. There should be incentives for scientists to acknowledge that their research focus should be abandoned and help them switch to another potentially more fruitful research area.”
What does this mean with regards to Bolt’s sprinting technique? To this day, sports scientists are buried in the “big idea” of vGRF (vertical ground reaction force), most notably presented by Weyand and others in 2000, which proposes that the forces our muscles generate at foot strike are the propulsive trigger for motion (J Appl Physiol (1985). 2000 Nov;89(5):1991-9. Faster top running speeds are achieved with greater ground forces not more rapid leg movements. Weyand PG, Sternlight DB, Bellizzi MJ, Wright S.). On the surface, this seems plausible – albeit with a warped and incomplete interpretation of Newton’s laws – that the harder we push into the ground, the faster we can accelerate ahead. Even Usain, in a YouTube post described his sprinting this way: “After the acceleration phase the goal is to: ‘Keep driving, driving, driving.. …. After completing the drive: ‘Get tall, knees up, dorsiflex, get your toes up, plant, push again.” However, this theory and description quickly lose persuasiveness considering studies have shown that Bolt’s maximum power output doesn’t match his maximum running velocity and that “less than 8% of the energy his muscles produced was used for motion.” (On the performance of Usain Bolt in the 100 m sprint, J J Hernández Gómez, V Marquina and R W Gómez; Published 25 July 2013/European Journal of Physics, Volume 34, Number 5). O. Helene and M. T. Yamashita, in The force, power and energy of the 100 meter sprint, Am. J. Phys. 78, 307 (2010), further noted that the maximum force, the maximum power, and the total mechanical energy values produced by Bolt were, surprisingly, smaller in 2009 than in 2008 when he broke his own WR.
What Bolt has recounted (“get tall, knees up, dorsiflex, get your toes up, plant, push again”) is considered the “classical” approach to sprinting. The difficulty in accepting this model is that Bolt truly doesn’t run that way. Hard to imagine, especially in the world of elite-level athletics where mechanics are obsessively critiqued over and over again, such a discrepancy between perceived and real-time action could exist. Show me where Bolt drives? Pushes? Plants? There is not enough time in the stride cycle for these things, where even the most minute fluctuations in timing are disastrous. His elongated stride? Notice how his foot touches beneath his body. His driving forward? Look at his compact thigh angle and hand position right before take-off. He pushes into the ground? The lack of complete knee extension at take-off indicates that his support leg is prepared for recovery mode. The research flounders, as scientists and bloggers attempt to correlate or reconcile his stride length, step frequency, taller frame, strength, acceleration, longer (relative) ground contact time, resistance to air drag, leg stiffness. Nevertheless, one of world’s foremost experts on human performance, SMU professor Dr. Peter Weyand (who has intensively studied Usain Bolt’s running characteristics and is the foremost proponent of the force-generation model), summarized in 2014, “Yet despite interest, incentives and intervention options that are arguably all without precedent, the scientific understanding of how the fastest human running speeds are achieved remains significantly incomplete.”
So what gives? Lost is the fundamental idea that “locomotion is a ‘falling-forward’ cycle, in which the body mass falls forward and then rises again. Mass that falls from a higher altitude falls faster…” (“The Evolution Of Speed In Athletics”, Adrian Bejan, Edward Jones and Jordan D. Charles – International Journal of Design & Nature and Ecodynamics, Volume 5(2010), Issue 3). This concept is not new. Throughout the ages, many have understood this relationship, from Leonardo Da Vinci (“Motion is created by the destruction of balance…”) to British physiologist Graham Brown (“It seems that the act of progression itself – the centre of mass of the body is allowed to fall forwards and downwards under the action of gravity….”) to the father of podiatric biomechanics Dr. Merton Root (“Vertical forces become less than body weight when the center of gravity of the body passes over the foot…”). In 2010, the lesser recognized study by F. Kugler and L. Janshen (“Body Position Determines Propulsive Forces In Accelerated Running”, J. Biomech January 19, 2010Volume 43, Issue 2, Pages 343–348) indicated that “…greater forward leans of the body which finally resulted in greater propulsive forces. Consequently, maximizing forward propulsion requires optimal, not maximal force application.”
As applied to running, these insights were systematically presented and expounded by Dr. Nicholas Romanov (Pose Method), and the only model that acknowledges how Bolt effectively utilizes gravity, specifically gravitational torque, to his advantage (“Analysis Of Usain Bolt’s Running Technique”, http://www.posemethod.com). Romanov articulates how Bolt, as if released from a slingshot, receives a horizontal propulsive thrust from the angular acceleration of his Center of Mass (COM). Since force is a vector property, this angular acceleration is determined by how optimally Bolt rotates on the fulcrum of his foot at the peak of maximum leverage. As a biological system that must organize and integrate a complexity of elements in the blink of an eye, Bolt handles force via the experience of rapid accumulation and loss of bodyweight during the stance phase. This “experience” provides a feedback signal common to all bipedals, a temporaneous equilibrium used as a perceptive nudge to move us from one foot to another. Without succumbing to the potential degradation of momentum, Bolt is able to maintain a more consistent velocity, moving his body in a continuous flow of energy. In its simplest terms, he is falling better, more powerfully and with less wasted effort.
It’s now time to start looking outside this simplistic model of sprinting as force dependent. Although the basic F= ma and stride length x stride frequency formulas hold true when discussing the general principles of physics, all the forces that are operating in a system of movement must be taken into account. There is no factual evidence that sprinters are best served by intensifying force application. The reality is this: sprinting requires the remarkable ability to absorb, withstand, control, recoil and transfer the forces they encounter. Bolt’s genius is his skill. Of similar brilliance was Jesse Owens, whose legendary coach Larry Snyder described his footstrike as “the lightest tread I have ever seen.” (“The Training Of Jesse Owens,” 1956, Clinic Notes, NCAA Coaches Association). When Bolt sprints, it has been equally written, “The metal of his spikes clacks against the surface of the track like a tap dancer’s shoes on the stage.” (Sports Illustrated, July 2016, Tim Layden).
These are hardly the descriptions of hulks brutishly striking the ground! Of note, according to David Epstein, author of The Sports Gene, biomechanical analysis of the speed of Jesse Owens’ joints shows that had he been running on the same surface as Bolt, he would have been within one stride of the modern champion, almost indistinguishable. Those who oppose what Bolt accepts cannot match his speed. They lose time with every step, their inefficiency both unnecessary and counterproductive. He is a warrior at one with his environment. His emotional focus and mental toughness almost superhuman. Win or lose (and I’m betting on the former), Bolt has set a unique standard of athletic precision. Watching him, I’m reminded of a quote by Tony Robbins: “Push will wear you out. When you’re pushing to do something you only have so much willpower. But when you’re being pulled, when there’s something larger than yourself that you’re here to serve, [it] brings you energy, transforms.” As they say, sometimes the answers are right in front of you. High-profile, dominant ideas be damned.