In early 2024, Max Grotner, Head of Performance Concepts at Puma, was studying the results of tests conducted by the company’s research and sports science department at its lab in southern Germany. His team was working on developing a new high-performance shoe for long distances, the Fast - R Nitro Elite 3, made of newly engineered thermoplastic polyurethane foam and a spoon-shaped carbon fiber plate. Initial lab results looked extremely promising—almost astonishing.
Every athlete from Grotner's team, who were tested on high-precision treadmills, showed improvement in 'running efficiency'—a measure of the amount of metabolic energy used to maintain a constant speed—while wearing the Nitro Elite 3 compared to other leading shoes. Theoretically, this meant that anyone could run a marathon faster or easier in Puma shoes compared to competing brands, which is every running shoe designer’s dream.
If this claim holds true, the Nitro Elite 3 would become an indispensable choice for marathon runners worldwide.
But Puma had to test it at an independent lab, so Grotner sent prototypes of the shoe to the Integrative Motion Lab at the University of Massachusetts Amherst, supervised by Walter Hoogkamer, an expert in biomechanics and energy. Hoogkamer is highly regarded in the athletic footwear industry, thanks to research he co-authored with Roger Kram, a physiologist who managed the movement lab at the University of Colorado Boulder.
A study conducted in 2018 found that Nike’s then-super shoe (Vaporfly) reduced 'running energy cost' by an average of 4 percent, potentially allowing elite athletes to 'run significantly faster'—a controversial claim that led to calls from a major sporting body to ban that shoe.
Hoogkamer conducted a study on the Nitro Elite 3, comparing its performance to another Nike shoe, the Alpha Fly 3, Adidas's Adios Pro Evo, and its predecessor Nitro Elite 2.
Among 15 athletes tested, Hoogkamer found that each of them 'recorded their best running efficiency rate using comparable shoes.' The study concluded that the Nitro Elite 3 could improve running efficiency by between 3.1 percent and 3.6 percent compared to the latest marathon shoes, a gain that could allow a three-hour marathon runner to shave off about 4 and a half minutes from their personal best.
Grotner expressed great happiness, saying, 'They replicated our results. It’s no longer just our lab; it’s an external lab now.'
Hoogkamer published the results along with a 'conflict of interest' appendix stating that the author 'received research grants from Puma.' Nevertheless, Puma issued a press statement last year asserting that it possessed data proving that the Puma Fast - R Nitro Elite 3 leads the running shoe category, to promote its launch at the Boston Marathon.
However, Carson Caprara, Head of Products at Brooks Running, a competitor in the footwear industry, stated that these scientific studies are useful educational tools for brands.
But he noted that testing protocols are often limited in scope; Puma’s Massachusetts study and Nike’s Colorado study limited their running tests to athletes running on treadmills for just five minutes at a time.
Companies often tout the scientific foundations of their athletic footwear; in a magazine ad from the mid-1980s, Nike promoted its Air Max 1 shoe, giving it a scientific aura, using technical terms to appeal to seasoned runners' desire for a tangible performance edge.
Yet no brand had committed to conducting an academic study of its shoe technology until Nike launched the Flyknit shoe before Eliud Kipchoge’s attempt to break the two-hour marathon barrier in 2017. During the development of a prototype in 2016, Nike tasked Kram, a member of Nike’s scientific advisory board, to test the shoe's efficacy against other leading marathon shoes. The results of the study—which showed the shoe outperforming its rivals by 4 percent—were widely reported in the press. The shoe was later released under the name Vaporfly 4%.
However, promoting a new shoe based on an academic study raised some eyebrows. Even as athletes began to break world records while wearing these shoes, journalist Matt Hart wrote in his book Win at All Costs: 'It was hard to dispel health doubts, given that Nike was the one funding the study.'
The success of the Flyknit shoe led to an era where all brands raced to develop a super shoe that combined high-density layers of supercritical foam with carbon fiber plates. It also highlighted the importance of scientific analysis, as each company sought to prove—backed by documented data—that its shoe had features that others lacked. Hoogkamer states: 'Many of these people have worked with me and Roger; thus, this has become common in shoe companies.'
Some brands, such as Under Armour, have established advanced laboratories in pursuit of a competitive edge. Tom Luddick, the Senior Director of Footwear Innovation at the company, described the newly created lab in Baltimore as 'world-class, even better than all the other labs in the field,' noting that it was the key to the success of the Velocity Elite line of marathon running shoes. Other brands have also strengthened their ties with universities to leverage their resources and expertise. Adidas is conducting these tests in its in-house lab at its headquarters in Bavaria, and in the field, in places like Kenya, to simulate the conditions in which some athletes live and train.