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Advancements in running shoe technology and their effects on running economy and performance – a current concepts overview
Sports Biomechanics
Abstract
Advancements in running shoe technology over the last 5 years have sparked controversy in athletics as linked with clear running economy and performance enhancements. Early debates mainly surrounded ‘super shoes’ in long-distance running, but more recently, the controversy has filtered through to sprint and middle-distance running with the emergence of ‘super spikes’. This Current Concepts paper provides a brief overview on the controversial topic of super shoes and super spikes. The defining features of technologically advanced shoes are a stiff plate embedded within the midsole, curved plate and midsole geometry, and lightweight, resilient, high-energy returning foam that – in combination – enhance running performance. Since the launch of the first commercially available super shoe, all world records from the 5 km to the marathon have been broken by athletes wearing super shoes or super spikes, with a similar trend observed in middle-distance running. The improvements in super shoes are around 4% for running economy and 2% for performance, and speculatively around 1% to 1.5% for super spikes. These enhancements are believed multifactorial in nature and difficult to parse, although involve longitudinal bending stiffness, the ‘teeter-totter effect’, the high-energy return properties of the midsole material, enhanced stack height and lightweight characteristic of shoes.
... This progression is often credited to Nike circa 2016 but similar concepts were also allegedly undertaken by Fila two decades earlier [1]. Either way, many of the recent performances in competitive distance running have been partly attributed to footwear utilising novel approaches to sports engineering [2,3]. ...
... Pebax is typically lighter and more efficient in its energy storage and return than traditional sole foam materials, such as ethylene vinyl acetate (EVA) or thermoplastic polyurethane [8]. The level of energy return with a Pebax sole has been reported to be as high as 87%, whereas traditional distance running shoes were only cited in the range of 65-75% [3]. ...
... Answer: It should be noted that prior to introduction of supershoes, few rules were in place to regulate athletic footwear design. However, after several distance running records were broken and the subsequent controversy emerged, World Athletics created a set of rules for running footwear design in 2020 [3] and revised them in 2022 [13]. These are designated the Athletic Shoe Regulations, C2.1A [13]. ...
Footwear used in competitive distance running has remained relatively unchanged in nature for decades. However, such technology has recently generated controversy with the introduction of so-called ‘supershoes’. Such footwear appear both aesthetically and functionally different to those used prior to their introduction and their arrival coincided with a spate of distance running world records being broken. The ten questions presented in this paper address a series of issues that relate to supershoes. These include their definition, what level of performance enhancement they provide and what impact they have had in competitive sport. Furthermore, it is explored how such technology is regulated and whether it should be considered fair. Via these questions, we hope to inform readers towards a greater understanding of this form of sports technology and highlight research and engineering gaps for future work.
... Though the mechanisms behind these changes are not clear, it is possible that the increased midsole compliance allows for runners to increase their leg stiffness when running in AFT and improve ME, though findings are mixed (Hata et al., 2022;Kerdok et al., 2002;Kulmala et al., 2018;Struzik et al., 2021). It is also important to note that a lower foam density, allows for AFT to have greater midsole stack heights (while maintaining a low mass) to accommodate greater carbon-plate curvature, allow for greater deformation without "bottoming out," increase contact time, and increase effective leg length (Hébert-Losier & Pamment, 2023;Kram, 2022;Nigg et al., 2020). ...
... Similarly to the PEBA foam, there are multiple possible mechanisms that may explain the contributions of the aforementioned carbon-plate on the total ME improvements from AFT. With a variety of different plate characteristics/configurations to consider, the actively contributing mechanism(s) of the plate toward ME improvements in AFT are still undetermined (Hébert-Losier & Pamment, 2023). ...
... Additionally, these acute improvements in energetic cost observed in AFT have been attributed to biomechanical changes observed in AFT compared to more traditional racing footwear, including decreased ankle positive and negative work, more efficient triceps surae contractions with decreased ankle plantarflexion velocities, decreased MTP joint work, and decreased energy loss at the MTP jointHunter et al., 2019;Ortega et al., 2021). These improvements in ME and changes in biomechanics are attributed to the curved, embedded carbon fiber plate in AFT, along with high stack, lightweight, compliant and resilient supercritical midsole foam that provides high levels of cushioning and energy return(Hébert-Losier & Pamment, 2023;Kram, 2022;Nigg et al., 2020). ...
“Super shoes,” also known as advanced footwear technology (AFT), have gained notoriety due to a combination of technologies that improve running economy (RE), or efficiency, by 2.5-4% (Hoogkamer et al., 2018; Hunter et al., 2019; Joubert & Jones, 2022). These acute effects have been partially explained by changes in ankle and metatarsophalangeal joint mechanics (Farina et al., 2019; Hoogkamer et al., 2019; Ortega et al., 2021). It also seems that runners experience decreased muscular soreness when using AFT in workouts (Castellanos-Salamanca et al., 2023). With the prevalence of AFT being used for workouts as well as races, this research investigates the potential long- term benefits or drawbacks of using these shoes regularly in workouts by comparing the effects of training in super shoes to training in traditional racing flats on overall running efficiency, shoe-specific efficiency, and biomechanics. A pilot study was conducted to investigate the long-term effects of using Nike Vaporflys (VP) in workouts by comparing 8 weeks of training in VP vs Nike Waffle flats (FL). Collegiate cross country runners (n=8) completed pre- (PRE) and post-intervention (POST) lab testing in both VP and FL. They then were assigned either VP or FL for an 8-week intervention. A weekly questionnaire detailed mileage, shoes worn for workouts/races, perceived effort, and muscular soreness. The results from the pilot study suggested a potential footwear specificity of training principle, where runners become relatively more efficient in the shoe they train in. Additionally, FL trained runners improved their overall RE (non-shoe- specific) to a greater extent than VP trained runners, though this result should be interpreted with caution due to small sample and uneven group sizes. Using similar methodology, a second phase intervention study was conducted with competitive cross country runners (n=13). In this study phase, associations between primary RE outcomes and exploratory biomechanics measures were tested in correlational analyses. Additionally, ANCOVA models were used to identify significant predictors of shoe- specific and overall RE changes. In the second phase study, VP trained runners increased relative efficiency in VP, and FL trained runners improved relative efficiency in FL. FL trained runners still improved overall RE to a greater degree than VP trained runners, though by a smaller margin compared to the pilot study. Correlations and linear regression models revealed that possible mechanisms behind this “learned” response to training in VP may include changes in ankle joint velocities and increased MTP joint dorsiflexion velocity when running in VP. VP trained runners generally experienced less soreness and exertion during workouts, potentially allowing for increases in training load when using AFT during hard running workouts. These results supported the findings of our pilot study that suggest a specificity of training effect where participants improved RE more from PRE to POST when running in the shoe type they trained in. While training in FL may afford potentially greater overall ME improvements from workouts, injury risk should be considered. Future longitudinal research should be conducted to identify mechanisms through which runners “learn” how to use AFT more effectively, which may provide insight for researchers and footwear companies to further optimize AFT.
... 7 From the onset of the release of the first super shoes, a consistent finding in running research has been that running economy, the steady-state oxygen uptake below intensities associated with the second ventilatory/lactate threshold, 8 is improved by wearing these shoes. 9,10 Differences in efficacy were found between brands and models of super shoe, 11 but the overall consequence of the proliferation of the advanced footwear technology has been an improvement in finishing times in running events where minimizing energy cost is a key factor, from 5 km to the marathon. 12 Indeed, Bermon et al 6 showed that elite men gained a 1.2% decrease in marathon race times between 2016 and 2019, with elite women having an even greater improvement of 2.0%. ...
... 12 Indeed, Bermon et al 6 showed that elite men gained a 1.2% decrease in marathon race times between 2016 and 2019, with elite women having an even greater improvement of 2.0%. However, not all athletes are positive responders to this new technology (ie, they are nonresponders 10 ), with findings that the super shoes do not work so well at a set slower speed. 13 The focus of much previous research on the effects of super shoes on running was on elite or well-trained athletes, 6,9 but research has shown that the greatest proportion of male New York City Marathon finishers take between 3.5 and 4 hours to complete the distance, with the greatest proportion of women taking 4 to 4.5 hours. ...
... We first hypothesized that energy cost would be reduced in the super shoes, which was supported by our findings, with a 3.8% reduction in oxygen consumption at the slower mean test speed of 9.4 km·h −1 and a 5.0% reduction at a mean speed of 11.5 km·h −1 . These improvements are similar in magnitude to those found in previous research on faster athletes 10 and show that even recreational marathon runners (3.5-4.5 h for the marathon) can benefit from advanced footwear technology. We also found that heart rate was lower in the super shoes, although the effect was smaller, but which could be an important physiological factor over a long-distance event like the marathon. ...
Purpose: Advanced footwear technology is prevalent in distance running, with research focusing on these "super shoes" in competitive athletes, with less understanding of their value for slower runners. The aim of this study was to compare physiological and biomechanical variables between a model of super shoes (Saucony Endorphin Speed 2) and regular running shoes (Saucony Cohesion 13) in recreational athletes.
Methods: We measured peak oxygen uptake (VO2peak) in 10 runners before testing each subject 4 times in a randomly ordered crossover design (ie, Endorphin shoe or Cohesion shoe, running at 65% or 80% of velocity at VO2peak [vVO2peak]). We recorded video data using a high-speed camera (300 Hz) to calculate vertical and leg stiffnesses.
Results: 65% vVO2peak was equivalent to a speed of 9.4 km·h-1 (0.4), whereas 80% vVO2peak was equivalent to 11.5 km·h-1 (0.5). Two-way mixed-design analysis of variance showed that oxygen consumption in the Endorphin shoe was 3.9% lower than in the Cohesion shoe at 65% vVO2peak, with an interaction between shoes and speed (P = .020) meaning an increased difference of 5.0% at 80% vVO2peak. There were small increases in vertical and leg stiffnesses in the Endorphin shoes (P < .001); the Endorphin shoe condition also showed trivial to moderate differences in step length, step rate, contact time, and flight time (P < .001).
Conclusions: There was a physiological benefit to running in the super shoes even at the slower speed. There were also spatiotemporal and global stiffness improvements indicating that recreational runners benefit from wearing super shoes.
... Advanced footwear technology (AFT) shoes were first introduced by Nike in late 2016early 2017, and they consisted of performance-enhancing shoes that combine lightweight, resilient midsole foams with rigid moderators and pronounced rocker profiles in the soles [1]. Unlike traditional racing flats, AFT shoes are designed to improve running economy and performance through innovations such as enhanced bending stiffness, highenergy return foam, and increased stack height [2]. A recent systematic review stated that most of the recent research focused on investigating the impact of running shoe midsoles, bending stiffness, and heel-to-toe drop on athletic performance [3]. ...
... These characteristics also enabled great achievements such as Eliud Kipchoge's sub-2-h marathon, which would have been deemed unlikely without technological enhancements regarding AFT [7]. These improvements have been consistently supported by laboratorybased studies, which highlight that AFT reduces the energy cost of running by 2.7% to 4.4%, translating into enhanced performance for elite runners [2,8]. While AFT is now a standard choice for elite athletes during both training and competition, its adoption among non-elite runners is less understood. ...
Background: Advanced footwear technology (AFT) has gained popularity among non-elite runners due to its potential benefits in training and competition. This study investigated the training practices and reported outcomes in non-elite runners using AFT. Methods: A cross-sectional observational study was conducted with 61 non-elite runners competing in distances ranging from 5 km to marathons. The survey collected data on demographics, training parameters, footwear usage, perceived changes in running mechanics, and self-reported injuries. Results: The results revealed a significant positive correlation (R = 0.6, p < 0.0001) between years of AFT use and weekly training volume, indicating that more experienced runners are likely to incorporate AFT consistently into their routines. Conversely, a significant negative correlation (R = −0.5, p < 0.0001) was found between training volume and the number of weekly sessions using AFT, suggesting a selective approach to footwear use. Participants reported biomechanical changes, such as increased forefoot support (49%) and higher calf muscle activation (44%), alongside a 16% self-reported injury rate, predominantly affecting the calves. Conclusions: These findings highlight the importance of proper guidance and gradual adaptation to maximize the benefits of AFT while minimizing injury risks. Future research should explore the long-term impact of AFT on performance and injury prevention through longitudinal studies.
... In recent years, footwear manufacturers have focused on developing advanced footwear technologies (AFTs) that reduce the energy cost of running. [12][13][14][15] Although no formal definition exists, AFTs are characterized as "performance-enhancing footwear technologies that combine lightweight, resilient midsole foams with rigid moderators and pronounced rocker profiles in the sole" 13,16 The rigid moderator is a plate, usually curved, often made from carbon fiber and is typically embedded in the midsole. ...
... Individualization is not merely about identifying footwear that improves RE; rather, it entails developing footwear or footwear components that maximize RE according to an individual's physical, biomechanical, and environmental characteristics. 16,28 Individualization therefore requires developing footwear that causes improvements in RE via the aforementioned mediated pathway. Thus, the direct effect is inherent to footwear properties, and the mediated pathway is integral to maximizing the full effect of an individual's biomechanical characteristics. ...
Advanced footwear technologies contain thicker, lightweight, and more resilient midsoles and are associated with improved running economy (RE) compared with traditional footwear. This effect is highly variable with some individuals gaining a greater RE benefit, indicating that biomechanics plays a mediating role with respect to the total effect. Indeed, the energy generated by contractile elements and the elastic energy recovered from stretched tendons and ligaments in the legs and feet are likely to change with footwear. Therefore, if RE is to be maximized according to individual characteristics, an individualized approach to footwear selection is required. However, current theoretical frameworks hinder this approach. Here, we introduce a framework that describes causal relationships between footwear properties, biomechanics, and RE. The framework proposes that RE changes with footwear due to (1) a direct effect of footwear properties—for example, increased or decreased energy return—and (2) a mediating effect of footwear on ankle and foot biomechanics and the spring-mass system. By describing the total effect as 2 complementary pathways, the framework facilitates research that aims to separately quantify direct and mediating effects of footwear. This may permit the development of footwear materials that can separately target the direct and individual mediating effects.
... This is because Nike always innovate and release newest technology on their product, especially marathon shoes. Running performance has been demonstrated to be improved by advanced footwear technology, which is defined by characteristics like a stiff plate implanted inside the midsole, curved plate and midsole geometry, and lightweight, robust, high-energy returning foam [1]. When using these shoes compared to not wearing them throughout the same period, male elite distance runners' crucial speeds improved by 3.31% because to this technology [2]. ...
... When using these shoes compared to not wearing them throughout the same period, male elite distance runners' crucial speeds improved by 3.31% because to this technology [2]. Super shoes are thought to provide gains of about 4% for running economy and 2% for performance; super spikes may also have similar improvements [1]. This implies that improvements in shoe technology have an impact on running efficiency as well as the capacity to run faster for longer periods of time. ...
Reflecting societal developments, marathons have changed from being endurance tests to become venues for inclusivity and creativity. While COVID-19 has made virtual marathons more popular, advanced footwear such as carbon-plated shoes has sparked discussions about fairness. The future of the marathon depends on striking a balance between technological progress, ethics, and the environment. This essay looks at the current patterns and potential future paths of marathon running. The first section of the essay describes how advanced footwear and wearable technology have enhanced athlete performance and how new technology has changed marathon gear. The article also discusses the impact of the epidemic on virtual and online marathons, indicating that these race formats may become popular in the future. Finally, the environmental impact of the marathon is examined along with sustainable measures to mitigate it. In conclusion, this essay provides insightful viewpoints on future developments in marathon running. Maintaining the appeal of marathons and promoting fairness can be achieved by standardizing footwear technology. Creating interesting online venues for virtual marathons can increase participation. Setting high sustainability goals can help reduce ecological footprints. Marathons can benefit from positive environmental change through promoting information sharing and community involvement, which links them to broader sustainability objectives.
... The overall improvement in finishing times is likely attributable to 3 factors: (1) a larger pool of runners as more athletes compete in the Olympics, (2) improved training practices and enhanced professionalism among athletes, 28,29 and (3) improved running surfaces and shoes. 30 However, the Olympic Record has improved only 3 times since 1968, with an absolute improvement in winning time of ∼6 seconds up to 2020, with the quadratic model showing a relative plateau in performance after 1996. This is possibly unsurprising given the WR for the event has stood since 1998 21 and suggests that Olympic 1500-m finals are unlikely to get much quicker. ...
... Our earlier comment regarding improved running surfaces and shoes could be relevant here given the recent development of so-called "super spikes," which have been speculated to improve track running performance by up to 1.5%. 30 By contrast, there is less evidence of synthetic tracks improving performance beyond their first appearance in 1968, with only 2 athletes achieving a PR since those Games. A key factor in 2020 was that the winner, Ingebrigtsen, effectively had a pacemaker, Cheruiyot (KEN), who led for most of the race, not as a designated pacemaker but as part of his own tactical approach. ...
Purpose : This study determined the evolution of performance and pacing for each winner of the men’s Olympic 1500-m running track final from 1924 to 2020. Methods : Data were obtained from publicly available sources. When official splits were unavailable, times from sources such as YouTube were included and interpolated from video records. Final times, lap splits, and position in the peloton were included. The data are presented relative to 0 to 400 m, 400 to 800 m, 800 to 1200 m, and 1200 to 1500 m. Critical speed and D′ were calculated using athletes’ season’s best times. Results : Performance improved ∼25 seconds from 1924 to 2020, with most improvement (∼19 s) occurring in the first 10 finals. However, only 2 performances were world records, and only one runner won the event twice. Pacing evolved from a fast start–slow middle–fast finish pattern (reverse J-shaped) to a slower start with steady acceleration in the second half (J-shaped). The coefficient of variation for lap speeds ranged from 1.4% to 15.3%, consistent with a highly tactical pacing pattern. With few exceptions, the eventual winners were near the front throughout, although rarely in the leading position. There is evidence of a general increase in both critical speed and D′ that parallels performance. Conclusions : An evolution in the pacing pattern occurred across several “eras” in the history of Olympic 1500-m racing, consistent with better trained athletes and improved technology. There has been a consistent tactical approach of following opponents until the latter stages, and athletes should develop tactical flexibility, related to their critical speed and D′, in planning prerace strategy.
... Both long-distance and track running shoes are available on the market with new high-tech materials (i.e., carbon fiber plate in the midsole) [7]. However, the literature has focused mainly on reporting strengths and limitations of long-distance running shoes [8][9][10]. ...
... However, the literature has focused mainly on reporting strengths and limitations of long-distance running shoes [8][9][10]. Accordingly, there are no definitive data available for high-tech track running shoes [7], although their use is increasing among athletes. A recent article published by Healey et al. [11] suggests how the so-called "super spikes" shoes might provide advantages over traditional track spikes, but these can depend on the athlete's perception of the shoes and are based on specific competitions. ...
Research on high-tech running shoes is increasing but few studies are available about the use of high-tech track spike shoes (super spikes), despite their growing popularity among running athletes. The aim of this case study was to investigate kinematics, kinetics, and plantar pressures of an Olympic running athlete using two different types of shoes, to provide an easy and replicable method to assess their influence on running biomechanics. The tested athlete performed six running trials, at the same speed, wearing a pair of normal spikes shoes (NSS) and a super spikes shoe (SSS), in random order. SSS increased contact time, vertical impact, and swing force (Effect Size 3.70, 7.86, and 1.31, respectively), while it reduced foot-strike type and vertical ground reaction force rate (Effect Size 3.62 and 7.21, respectively). Moreover, a significant change was observed in medial and lateral load, with SSS inducing a more symmetrical load distribution between the left and right feet compared to the NSS (SSS left medial load 57.1 ± 2.1%, left lateral load 42.9 ± 1.4%, right medial load 55.1 ± 2.6%, right lateral load 44.9 ± 2.6%; NSS left medial load 58.4 ± 2.6%, left lateral load 41.6 ± 2.1%, right medial load 49.2 ±3.7%, right lateral load 50.8 ± 3.7%). The results of this case study suggest the importance of using individual evaluation methods to assess shoe adaptations in running athletes, which can induce biomechanical modifications and should be considered by coaches to ensure optimal running performance.
... At least, the general opinion that habitual shod runners are mostly rearfoot strike runners (Lieberman, 2010) needs to be reassessed and updated; the development of the new shoe techniques can provide more counterexamples. However, exactly which feature of AF affects the running performance is still controversial (Hébert-Losier, 2022), and likewise, we cannot conclude the main mechanism how AF induced rearfoot runners to run with decreased FSA better than other shoes. Another limitation of this initial pilot study is insufficient number of participants in each group. ...
Multiple influential studies argued that minimal footwear promotes forefoot running whereas cushioned footwear promotes rear foot strike. We readdressed effects of footwear on the foot strike pattern considering runners' habitual patterns. Based on the observed foot strike angle, we divided 9 participants into rearfoot, midfoot and forefoot runners. All participants then ran wearing 3 different shoes: performance boosting shoes, conventional shoes, and minimal shoes. We found a significant effect of shoes on foot strike angle and the interaction between the group and shoes. Contrary to well accepted arguments of previous studies, performance boosting shoes with thick outsoles induced the rearfoot group to run with decreased foot strike angle more effectively than minimal shoes. Our finding also revealed the hitherto seldom investigated effect of habitual patterns on adaptability.
... Advanced footwear technology (AFT) [1] provides substantial improvements in running economy [2] and performance [3], but there is still much debate about the relative contribution of the different shoe properties involved, including shoe mass [4], compliance [5], resilience [6], and longitudinal bending stiffness [7]. As a result, there has been a resurgence of research on the topic. ...
... Additionally, the modified rocker geometry in the Pro 4 may contribute to enhanced performance through an optimized teeter-totter effect 18 . However, the synergistic combination of weight reduction, different midsole geometry, and the same foam compliance also leads to an altered bending stiffness, likely overall resulting in the observed 1.31% improvement in running economy, highlighting the complex interplay of shoe design elements in performance enhancement 29 . ...
... Therefore, understanding aspects that influence running economy is helpful for competitive runners and coaches. One of these influences is footwear (Cheung & Ngai, 2015;Fuller et al., 2015;Sobhani et al., 2013), especially high-performance racing shoes with advanced footwear technology like high-energy-returning foams and carbon fibre plates (Hébert-Losier et al., 2022;Hoogkamer et al., 2018Hoogkamer et al., , 2019Joubert et al., 2023;Dustin P. Joubert & Jones, 2022;Rodrigo-Carranza et al., 2023). Since both competitive and recreational runners commonly use different types of shoes for specific purposes (e.g., training vs. racing) (Ramsey et al., 2022), it is important to know if Stryd RP, or any other Stryd metric, can reflect these small, but consequential (Langley & Langley, 2023;Rodrigo-Carranza et al., 2023), changes in running economy between shoe types. ...
It is unclear if running power (RP) estimated by the Stryd footpod device maintains its linear relationship to metabolic power (WMET) when switching between training and racing shoe types. This study determined if RP estimated by the Stryd footpod and its other spatiotemporal metrics reflect the improvement (decrease) in WMET when wearing high-performance racing shoes (HPRS; Nike AlphaFly Next%) compared to control training shoes (CTS; Nike Revolution 5). Fourteen well-trained runners completed two treadmill tests: Absolute Velocity Running Test (AVRT; 11.3–14.5 km·hr−1) and Relative Velocity Running Test (RVRT; 55–75% VO2MAX). WMET was determined with indirect calorimetry. RP was not significantly different between shoe types (p > 0.432) during the AVRT, but WMET was ~5% lower in HPRS (p < 0.001). During the RVRT, participants ran ~6% faster and at ~6% higher RP (both, p < 0.001) in HPRS for the same WMET (p = 0.869). Linear mixed models confirmed WMET was ~5% lower in HPRS for a given RP (p < 0.001). Still, RP and WMET were strongly related within shoe types (p < 0.001, conditional-R2 = 0.982, SEE = 2.57%). Form power ratio and ground contact time correlated with energetic cost (p < 0.011) but did not fully reflect the influence of shoe type. Therefore, runners should account for their shoe type when using RP to indicate WMET between training and racing.
... In 2020, Nike released two new distance track spikes adopting similar technology as the road shoes: the Nike ZoomX Dragonfly (DFLY) and the Nike Zoom Air Victory (VIC). Both new spikes include a stiff plate and lightweight, resilient foam that may work together to enhance running performance (Hébert-Losier & Pamment, 2023). While the biomechanical and metabolic impacts of road racing shoes on long distance racing have been studied over the past several years, very little research to date has investigated the biomechanical differences between track spikes containing AFT compared to traditional track spikes. ...
... Although there are several possible reasons for these performance improvements, evidence suggests that AFT is a key driver (3)(4)(5)(6)(7)(8)(9)(10)(11). Understanding why women may benefit more from AFT than men first requires an understanding of the mechanisms through which the elements of AFT generally create performance advantages [for review, see (13,14)]. Improvements in running economy at submaximal velocities (15) seem to arise from the combination of a) an increase in longitudinal bending stiffness (LBS), which limits energy dissipated at the metatarsophalangeal (MTP) and ankle joints during dorsiflexion, and b) the new midsole materials, which have a higher energy retention capacity (15,16). The addition of AFT into track spikes and its effects on sprint and middle-distance performance metrics remains largely unexplored (17). ...
Recent improvements in elite running performances across all distances have been largely attributed to the introduction of advanced footwear technology (AFT), which features a curved and stiff plate working synergistically with a new generation of midsole foams demonstrating enhanced resilience and compliance. These recent improvements appear to be considerably more pronounced in women's events, highlighted by improvements in road racing world records by an average of 3.7% (range: 2.6%–5.2%) compared to mean progressions of 1.5% (range: 1.3%–1.9%) in the same men's events. Although there is a growing body of research investigating the mechanisms underpinning running performance enhancements derived from AFT, there remains no explanation for potential sex-based differences in their benefits. We overview the currently available evidence and highlight why the recent direction of AFT research provides a barrier to progress by focusing primarily on male athletes. We subsequently provide our perspective on why women may be benefiting from the new generation of shoes more than men, suggest potential mechanisms leading to hypotheses that need to be further investigated in upcoming studies, and finally propose that factors outside of footwear innovation may have concurrently driven the recently observed performance evolutions.
... However, a consistent and direct effect of longitudinal bending stiffness on running economy has not yet been identified, possibly due to large individual differences 45 . The influence of other specific characteristics such as carbon fibre plate shape and position, stack-height, drop, or uppers, is still unclear 46 . Notably, isolated effects could disappear or interact differently with other features when combined, further challenging their thorough investigation. ...
Technologically advanced running shoes (TARS) improve performance compared to classical running shoes (CRS). Improved race performance has been attributed to metabolic savings in male runners, but it remains unclear if these same benefits are experienced among females and in recreational runners. The mechanisms behind these benefits are still not fully understood despite the need for optimisation, and their influence on injury mechanisms has not been explored. Here we combined biomechanical, physiological, and modelling approaches to analyse joint mechanics, oxygen uptake, and tibial load in nineteen male and female recreational runners running with CRS and TARS at their individual lactate threshold speed (12.4 ± 1.9 km/h). Oxygen uptake was 3.0 ± 1.5% lower in TARS than in CRS. Ankle dorsiflexion, joint moment and joint power were reduced in TARS compared to CRS at various phases of stance including midstance, while knee joint mechanics were mostly similar throughout. There were no significant differences for tibial bending moment during the stance phase but cumulative tibial damage per kilometre was 12 ± 9% lower in TARS compared to CRS. Our results suggest that running with TARS reduces oxygen cost in recreational female and male runners, which may partly be explained by differences in lower limb joint mechanics. The lower cumulative tibial bone load with TARS may allow runners to run longer distances in this type of shoe compared to CRS.
... Thanks to advancements in materials science, athletic shoes have undergone rapid development, especially in recent years. Advanced, in the context of this article, means lightweight footwear technologies that use a compliant and resilient foam as the cushioning element in combination with curved stiffening elements running along the sole [2,3]. In the case of spiked track running shoes, some manufacturers add a spike plate in the forefoot to which the spikes are attached [4]. ...
Advanced footwear technology (AFT) is currently being debated in sports. There is a direct evidence that distance running in AFT improves running economy. In addition, there is indirect evidence from competition performance for improved running performance from using AFTs in middle- and long-distance running and sprinting events. However, the extent to which world-class performance is affected across the full range of track and road racing events between genders has not been systematically analyzed. This study examined publicly available performance datasets of annual best track and road performances for evidence of potential systematic performance effects following the introduction of AFT. The analysis was based on the 100 best performances per year for men and women in outdoor events from 2010 to 2022, provided by the world governing body of athletics (World Athletics). We found evidence of progressing improvements in track and road running performances after the introduction of AFT for road races in 2016 and AFT for track racing in 2019. This evidence is more pronounced for distances longer than 1500 m in women and longer than 5000 m in men. Women seem to benefit more from AFT in distance running events than men. For the sprint events (100 m to 400 m hurdles), the peak performance gains in 2021 and 2022 compared to the pre-AFT period ranged from 0.6 to 1.1% and from 0.4 to 0.7% for women and men, respectively. For middle-distance events (400 m to 3000 m steeplechase), peak performance gains ranged from 0.6 to 1.9% and from 0.6 to 0.7% for women and men, respectively. For distances from 5000 m to the marathon, performance gains ranged from 2.2% to 3.5% and 0.7% to 1.4% for women and men, respectively. While the observational study design limits causal inference, this study provides a database on potential systematic performance effects after introducing advanced shoes/spikes in track and road running events in world-class athletes. Further research is needed to examine the underlying mechanisms and, in particular, potential gender differences in the performance effects of AFT.
... The VP4 contained novel technologies claiming to return energy, which ultimately led to the emergence of shoes with advanced footwear technology (AFT). Although there is no consensus definition (H ebert-Losier & Pamment, 2023), shoes with AFT typically contain a thicker midsole than previously available racing shoes that is constructed of polyether block amide (PEBA) elastomer foam instead of the traditionally used ethylene-vinyl acetate (EVA) (Burns & Tam, 2020). PEBA contains greater energy-return properties than EVA (Bermon, 2021;Muniz-Pardos et al., 2022) and is lighter, meaning it is possible to have a thicker midsole with a negligible increase in shoe mass. ...
... However, a consistent and direct effect of longitudinal bending stiffness on running economy has not yet been identified, possibly due to large individual differences 45 . The influence of other specific characteristics such as carbon fibre plate shape and position, stack-height, drop, or uppers, is still unclear 46 . Notably, isolated effects could disappear or interact differently with other features when combined, further challenging their thorough investigation. ...
Introduction:
Tibial stress injuries are a burdensome injury among military recruits. Military activities include running and the carriage of additional weight, and this may be related to the high risk of bone stress injuries. The aim of this study was to quantify tibial loading when running at two different speeds, with and without additional weight, and to quantify their combined influence.
Methods:
Fourteen male distance runners who ran at least 40 km per week ran barefoot on a force-instrumented treadmill in four conditions representing preferred running speed (mean (SD) 3.1 (0.3) m/s) and 20% increased running speed (3.8 (0.4) m/s), with and without 20% of body weight carried in a weight vest. Kinematics and kinetics were synchronously collected. Bending moments were estimated about the medial-lateral axis of the tibial centroid located 1/3rd of the length from distal to proximal. Static equilibrium was ensured at each 1% of stance. Peak bending moments were obtained in addition to cumulative-weighted loading, where weighted loading accounted for the relative importance of the magnitude of the bending moment and the quantity of loading using a bone-dependent weighting factor.
Results:
There were no interaction effects for running speed and weight carriage on peak or cumulative tibial loading. Running at a 20% faster speed increased peak and cumulative loading per kilometer by 8.0% (p < 0.001) and 4.8% (p < 0.001), respectively. Carriage of an additional 20% of body weight increased peak and cumulative loading per kilometer by 6.6% (p < 0.001) and 8.5% (p < 0.001), respectively.
Interpretation:
Increasing the physical demand of running by increasing speed or weight carriage increased peak tibial loading and cumulative tibial loading per kilometer, and this may increase the risk of tibial stress injury. Running speed and weight carriage independently influenced tibial loading.
... 6,7 Many factors can affect performance such as maturation, 8 improved training 9 and technological advances. 10 However, as the primary reason for an athlete to dope is to artificially enhance their performance, it is intuitive to consider the analysis of their sporting performance as important information for ADOs to inform their antidoping activities. To this effect, the most recent version of the International Standard for Testing and Investigations 7 highlights the use of sport performance history, including sudden major improvements and/or sustained periods of high performance as relevant factors indicating possible doping/increased risk of doping. ...
As the aim of any doping regime is to improve sporting performance, it has been suggested that analysis of athlete competitive results might be informative in identifying those at greater risk of doping. This research study aimed to investigate the utility of a statistical performance model to discriminate between athletes who have a previous anti-doping rule violation (ADRV) and those who do not. We analysed performances of male and female 100 and 800 m runners obtained from the World Athletics database using a Bayesian spline model. Measures of unusual improvement in performance were quantified by comparing the yearly change in athlete's performance (delta excess performance) to quantiles of performance in their age-matched peers from the database population. The discriminative ability of these measures was investigated using the area under the ROC curve (AUC) with the 55%, 75% and 90% quantiles of the population performance. The highest AUC values across age were identified for the model with a 75% quantile (AUC = 0.78-0.80). The results of this study demonstrate that delta excess performance was able to discriminate between athletes with and without ADRVs and therefore could be used to assist in the risk stratification of athletes for anti-doping purposes.
... Without doubt, improved equipment has been vital for performance development in many endurance sports, with the clap skate in speed skating, 11 carbon fiber use in cycling, rowing, kayak, and paralympic events, and "super-shoes" in running 12 being primary examples. Another factor is improved preparation strategies for competitions held in different environmental conditions such as altitude and the heat. ...
Background:
Elite sport is continuously evolving. World records keep falling and athletes from a longer list of countries are involved.
Purpose:
This commentary was designed to provide insights into present and future trends associated with world-class endurance training based on the perspectives, experience, and knowledge of an expert panel of 25 applied sport scientists.
Results:
The key drivers of development observed in the past 10-15 years were related to (1) more accessible scientific knowledge for coaches and athletes combined with (2) better integration of practical and scientific exchange across multidisciplinary perspectives within professionalized elite athlete support structures, as well as (3) utilization of new technological advances. Based on these perspectives, we discerned and exemplified the main trends in the practice of endurance sports into the following categories: better understanding of sport-specific demands; improved competition execution; larger, more specific, and more precise training loads; improved training quality; and a more professional and healthier lifestyle. The main areas expected to drive future improvements were associated with more extensive use of advanced technology for monitoring and prescribing training and recovery, more precise use of environmental and nutritional interventions, better understanding of athlete-equipment interactions, and greater emphasis on preventing injuries and illnesses.
Conclusions:
These expert insights can serve as a platform and inspiration to develop new hypotheses and ideas, encourage future collaboration between researchers and sport practitioners, and, perhaps most important, stimulate curiosity and further collaborative studies about the training, physiology, and performance of endurance athletes.
... Many factors can affect performance such as maturation (Allem and Hopkins, 2015), improved training (Haugen et al., 2018) and technological advances (Hébert-Losier, 2023). However, as the primary reasons for an athlete to dope is to artificially enhance their performance, it is intuitive to consider the analysis of their sporting performance as important information for ADOs to inform their anti-doping activities. ...
... [1] Thanks to new findings in materials science, athletic shoes have undergone rapid development, especially in recent years. High-tech, in the context of this article, means extremely lightweight shoes that use a compliant "super foam" as the cushioning element in combination with a stiff, curved plate, often made of carbon, running along the sole [2,3]. In the case of spiked shoes, some manufacturers add a spike plate in the forefoot to which the spikes are attached [4]. ...
High-tech running shoes and spikes ("advanced footwear technology") are currently being debated in sports. There is direct evidence that distance running advanced footwear technology improve running economy; however, it is not well established to which extent world-class performances are affected over the range of track and road running events. This study examined publicly available performance datasets of annual best track and road performances for evidence of potential systematic performance effects following the introduction of advanced footwear technology. The analysis was based on the 100 best performances per year for men and women in outdoor events from 2010 to 2022, provided by the world governing body of athletics (World Athletics). We found evidence of progressing improvements in track and road running performances after the introduction of super distance running shoes in 2016 and super spike technology in 2019. This evidence is more pronounced for distances longer than 1500 m in women and longer than 5000 m in men. Women seem to benefit more from advanced footwear technology in distance running events than men. While the observational study design limits causal inference, this study provides a database on potential systematic performance effects following the introduction of advanced shoes/spikes in track and road running events in world-class athletes. Further research is needed to examine the underlying mechanisms and, in particular, potential sex differences in the performance effects of advanced footwear technology. Key Points • The study provides indirect evidence of the performance-enhancing effects of advanced footwear technology particularly for longer distances and in female athletes. • However, limitations of the study should be considered, such as the observational nature of the analysis and potential confounding factors such as performance-enhancing drugs. • The findings have implications for the design and use of advanced footwear technology in competitive distance running, highlighting the need to consider individual differences in anthropometrics and biomechanics and continue monitoring new footwear technologies' effects on athletic training performance.
... While footwear research has been foundational for demonstrating the performance enhancing capabilities of Advanced Footwear Technologies, not every runner benefits in the same way, and to the same extent. Large inter-runner variations in running economy have been observed with the use of the Nike Vaporfly 4% shoe (Barnes & Kilding, 2019;H ebert-Losier & Pamment, 2023). Runners have shown divergent results ranging from 3% improvements to 3% deterioration in running economy, in response to footwear modifications like increased longitudinal and forefoot bending stiffness (Chollet et al., 2023;Ortega et al., 2021). ...
Footwear science research has seen a roughly 10-fold increase in publications over the last 20 years. This commentary will focus on the three primary research themes of this time frame: methodological developments, running-related injuries, and performance. Within each theme, we summarise the knowledge generated through the substantial increase in publications over the last couple of decades. The methodological developments highlight both improvements in data analysis techniques as well as changes in how we measure variables of interest. Running-related injury prediction paradigms have evolved significantly during these years, which affect how we recommend moving forward in the field. Substantial excitement has filled the performance research field, as we discuss how the advent of Advanced Footwear Technologies altered the research questions and approaches. The undeniable growth in the field over in recent years can be attributed to a strong foundation of knowledge, nurtured by a curiosity to obtain understanding through holistic approaches. The community has embarked on the next stage of the journey, armed with new data collection tools and analytical methodologies, with the objective to better understand the effect of novel footwear design on performance enhancement and injury prevention.
... Further, differences in treadmill surface stiffness (Colino et al., 2020a;Colino et al., 2020b) and shoe use (Hoogkamer et al., 2018) between the current and previous case study could also contribute to physiological differences. Specifically, the athlete in our study was assessed on the shoes he used during the world record performance, and these shoes contained a carbon plate that may improve running economy (Hébert-Losier and Pamment, 2022). In contrast, the shoes used in the previous studies were standard racing shoes without carbon plates ). ...
Purpose: This study assessed the body composition, cardiorespiratory fitness, fiber type and mitochondrial function, and training characteristics of a 71-year-old runner who broke the world record marathon of the men’s 70–74 age category and held several other world records. The values were compared to those of the previous world-record holder.
Methods: Body fat percentage was assessed using air-displacement plethysmography. V ˙ O 2 max , running economy, and maximum heart rate were measured during treadmill running. Muscle fiber typology and mitochondrial function were evaluated using a muscle biopsy.
Results: Body fat percentage was 13.5%, V ˙ O 2 max was 46.6 ml kg⁻¹ min⁻¹, and maximum heartrate was 160 beats∙min⁻¹. At the marathon pace (14.5 km h⁻¹), his running economy was 170.5 ml kg⁻¹ km⁻¹. The gas exchange threshold and respiratory compensation point occurred at 75.7% and 93.9% of the V ˙ O 2 max , i.e., 13 km h⁻¹ and 15 km h⁻¹, respectively. The oxygen uptake at the marathon pace corresponded to 88.5% of V ˙ O 2 max . Vastus lateralis fiber content was 90.3% type I and 9.7% type II. Average distance was 139 km∙w⁻¹ in the year prior to the record.
Conclusion: The 71-year-old world-record holder marathon showed a relatively similar V ˙ O 2 max , lower percentage of V ˙ O 2 max at marathon pace, but a substantially better running economy than his predecessor. The better running economy may result from an almost double weekly training volume compared to the predecessor and a high type I fiber content. He trained every day in the last ∼1.5 years and achieved international performance in his age group category with a small (<5% per decade) age-related decline in marathon performance.
Objectives : This study aimed to report (1) the correlation between net metabolic cost (NMC) of running and Achilles tendon (AT) and ankle plantar flexor passive stiffness and (2) explore the relationship between passive stiffness and key running biomechanics. Methods : Twenty-two male recreational runners participated in this study. The runners performed a 5-minute run at 50% of their maximal aerobic speed as a warm-up on an instrumented treadmill, followed by a 6-minute run at 65% of their maximal aerobic speed wherein NMC was recorded. Passive stiffness was measured using a myotonometry device both before and after the run. Results : There was a negative linear relationship between NMC and AT stiffness. NMC and prerun AT stiffness demonstrated a significant negative correlation between leg stiffness and a significant positive correlation with braking peak force and step length. Moreover, we observed an increase in stiffness between prerun and postrun measurements at rest for the AT and both gastrocnemius muscles. Conclusion : Greater AT stiffness measured at rest is correlated with lower NMC.
Background While the acute effects of advanced footwear technology (AFT) on running biomechanics and efficiency have been extensively studied, the longitudinal effects of AFT use are unknown.
Objective The purpose of this study was to investigate the effects of using advanced footwear technology (AFT) versus traditional racing flats during running workouts on relative running economy (RE) and energetic cost (EC), and explore associations between changes in footwear-specific biomechanics and performance.
Methods Thirteen competitive runners were randomly assigned Nike Vaporfly Next% 3 (VP) or Nike Rival Waffle 5 (FL) for an 8-week intervention and completed pre- (PRE) and post-intervention (POST) lab testing in both shoes. Weekly training data, including mileage, workouts, and soreness, were collected via questionnaires. Subjects ran two 3-min trials at a self-selected cross-country race pace, with sagittal plane ankle and metatarsophalangeal (MTP) joint kinematics and kinetics recorded and analysed. Subsequently, four 5-min trials were completed at a self-reported submaximal pace, in a randomized order, and shoe-specific RE and EC were calculated and reported as VP% benefit the percentage RE or EC improvement in VP versus FL. Pearson′s correlations were tested between RE outcomes and exploratory biomechanics – measures, and independent samples t-tests tested for group differences in shoe-specific and overall efficiency changes from PRE to POST.
Results VP% benefit increased from PRE to POST in VP trained runners and decreased in FL trained runners. VP trained runners decreased ankle plantarflexion velocity in VP, increased ankle dorsiflexion velocity in VP, and decreased MTP plantarflexion velocity in FL. Correlations revealed several significant associations between metabolic outcome measures, and biomechanical and training variables.
Conclusions Metabolic data support a footwear specificity of training principle (habituation), where training in VP may enhance a runner′s ability to benefit from VP on race day. Associations reveal that this may be due to changes in footwear-specific biomechanics at the ankle and MTP joints. Future research should explore the potential mechanisms through which runners adapt to AFT to maximize their performance benefits.
Endurance performance declines with advancing age. Of the three main physiological factors that determine endurance running performance (maximal oxygen consumption [V̇O 2 max], lactate threshold, and running economy [RE]), V̇O 2 max appears to be most affected by age. While endurance performance declines with age, recently, endurance performance has rapidly improved in master athletes as the number of master athletes competing in endurance events has increased. Master athletes represent an intriguing model to study healthy aging. In this case study, we reassessed the physiological profile of a 76-year-old distance runner who broke the marathon world record for men over 70 years of age in 2018. This runner was tested a few months before breaking the world record and retested in 2024. Between 2018 and 2024, his marathon running velocity decreased significantly. Therefore, the purpose of this case study was to determine the physiological changes that explain his performance decline. RE remained similar to 2018, and while there was not a clear breakpoint in blood lactate, he still likely runs marathons at a high percentage (~90%) of his V̇O 2 max. However, V̇O 2 max declined by 15.1%. HRmax declined by 3.2% and maximal O 2 pulse declined by 12.4%, suggesting that maximal stroke volume and/or arteriovenous O 2 difference decreased. Altogether, although this marathoner continues to compete at an elite level, his performance has declined since his record-breaking marathon due to a reduction in V̇O 2 max. This is likely caused by reductions in maximal stroke volume and/or arteriovenous O 2 difference. We speculate that these changes reflect primarily age-related processes.
Understanding how shoe features affect motor control processes is crucial for designing targeted running shoes. The purpose of this study was to investigate adaptations of coupled movement components, i.e. kinematic synergies (kSYNs), when running with different shoe stack heights (19 mm, 35 mm, and 50 mm). The applied analysis combined a principal component analysis, support vector machine classifiers, and stride-to-stride variability (SSV) calculations. The results showed classification rates ranging from 82.9% to 94.4% across different stack heights. Notably, only the 50 mm stack height demonstrated increased SSV for the kSYNs that highly contribute to separating the two stack heights when compared to the 19 mm condition. The findings suggest that the motor control system adjusts to variations in stack height within certain limits by regulating task-relevant kSYNs.
In a randomized controlled cross-over study ten male runners (26.7 ± 4.9 years; recent 5-km time: 18:37 ± 1:07 min:s) performed an incremental treadmill test (ITT) and a 3-km time trial (3-km TT) on a treadmill while wearing either carbon fiber insoles with downwards curvature or insoles made of butyl rubber (control condition) in light road racing shoes (Saucony Fastwitch 9). Oxygen uptake, respiratory exchange ratio, heart rate, blood lactate concentration, stride frequency, stride length and time to exhaustion were assessed during ITT. After ITT, all runners rated their perceived exertion, perceived shoe comfort and perceived shoe performance. Running time, heart rate, blood lactate levels, stride frequency and stride length were recorded during, and shoe comfort and shoe performance after, the 3-km TT. All parameters obtained during or after the ITT did not differ between the two conditions [range: p = 0.188 to 0.948 (alpha value: 0.05); Cohen's d = 0.021 to 0.479] despite the rating of shoe comfort showing better scores for the control insoles (p = 0.001; d = −1.646). All parameters during and after the 3-km TT showed no differences (p = 0.200 to 1.000; d = 0.000 to 0.501) between both conditions except for shoe comfort showing better scores for control insoles (p = 0.017; d = −0.919). Running with carbon fiber insoles with downwards curvature did not change running performance or any submaximal or maximal physiological or biomechanical parameter and perceived exertion compared to control condition. Shoe comfort is impaired while running with carbon fiber insoles. Wearing carbon fiber insoles with downwards curvature during treadmill running is not beneficial when compared to running with control insoles.
Purpose. Advanced Footwear Technology (AFT) are performance enhancing shoes that combines lightweight, resilient midsole foams with rigid moderators and pronounced rocker profiles in the soles. This was a pilot study that explored the use of AFT during training and competition and to describe the injuries sustained in amateur runners.
Methods. This was a retrospective cross-sectional observational pilot study in which 61 amateur runners completed an anonymous questionnaire to determine: demographic characteristics; running activities and injuries sustained using AFT.
Results.The main brands used were Nike (41%), Adidas (12%), Hoka (11%), Sauconi (10%), New Balance (8%), Puma (8%), Brooks (5%), Mizuno (3%), Under Armour (2%). Runners used AFT once a week (67.8%), up to three times a week (27.1%), and 6 times a week (5.1%) less than a year (35%), from 1 to 3 years (50%), and more than 3 years (15%). The 61.7% runners perceived a change in running technique, with greater support on the forefoot (40%), higher activation of calf muscles (36%), different torso position (13.3%), and running instability (10.7%). Onset of delayed muscle soreness appeared after 24 hours training session (62.1%), after 3 months (20.7%), after 1 month (10.3%), and after 1 week (6.9%) the use of AFT. Eight runners (11.8%) reported that they sustained an injury after the use of AFT.
Conclusions. The use of AFT leads to a change perception in running technique amateur runners. Therefore, they should introduce them gradually in their training routine.
Wearing the right sportswear is one of the essential points in exercising, which is mainly neglected. Sportswear should be suitable for the ambient temperature and not cause more heat or cold in the athlete's body. On the other hand, increased sweating and blood circulation during exercise should not cause fatigue or heatstroke in the athlete. Nanotechnology has grown significantly in the field of producing more efficient equipment in the field of sports. The increase in demand in sports for complete sports equipment has revealed the necessity of using the highest quality materials in this sector. In the world of championship sports, a minor change in equipment can lead to significant changes in causing failure and victory. Since the sole is the most critical part of sports shoes, with the introduction of nanotechnology and nanocomposites, it is possible to help athletes rush and increase their sense of calm and satisfaction. Using nanocomposites in the soles of shoes can improve some of their characteristics, prevent the smell and sweat of shoes, and induce water repellency in these shoes. In this research, titanium dioxide (TiO2) nanocomposite, along with cellulose, has been used to create antibacterial and hydrophobic properties in the soles of sports shoes. The synthesized nanocomposite has been synthesized using the least amount of chemicals, which shows this method's easy and cost-effective synthesis.
Endurance exercise performance is known to be closely associated with the three physiological pillars of maximal O2 uptake (V̇O2max), economy or efficiency during submaximal exercise, and the fractional utilisation of V̇O2max (linked to metabolic/lactate threshold phenomena). However, while ‘start line’ values of these variables are collectively useful in predicting performance in endurance events such as the marathon, it is not widely appreciated that these variables are not static but are prone to significant deterioration as fatiguing endurance exercise proceeds. For example, the ‘critical power’ (CP), which is a composite of the highest achievable steady‐state oxidative metabolic rate and efficiency (O2 cost per watt), may fall by an average of 10% following 2 h of heavy intensity cycle exercise. Even more striking is that the extent of this deterioration displays appreciable inter‐individual variability, with changes in CP ranging from <1% to ∼32%. The mechanistic basis for such differences in fatigue resistance or ‘physiological resilience’ are not resolved. However, resilience may be important in explaining superlative endurance performance and it has implications for the physiological evaluation of athletes and the design of interventions to enhance performance. This article presents new information concerning the dynamic plasticity of the three ‘traditional’ physiological variables and argues that physiological resilience should be considered as an additional component, or fourth dimension, in models of endurance exercise performance. image
Background:
Poor information is available regarding real field data on the different factors that could have an influence on curve sprint and its association with anthropometric and strength parameters.
Methods:
We designed a crossover pilot-study that enrolled 14 track and field athletes of 200 and 400 m (8/14 men, age: 20.5±2.3 years, height: 1.73±0.06 m; body mass: 60.5±6.2 kg) that performed randomly in two different days assessment of anthropometric parameters, jump test by squat jump (SJ) and triple hop distance (THD), performance during a 20-m curve sprint (day 1), and assessment of 1RM for right and left limb on Bulgarian split squat (BSS) (day 2). The unpaired t test and Pearson's correlation were used for data analysis.
Results:
No statistical differences for anthropometric and strength parametric parameters between right and left lower limbs were observed. Twenty-meter curve sprints were negatively associated with body mass (P=0.0059, R=-0.7) and Body Mass Index (BMI; P=0.032, R=0.6). Moreover, a negative association was observed with SJ height (P=0.0025, R=-0.7), speed (P=0.0028; R=-0.7), strength (P=0.009, R=-0.7) and power (P=0.009, R=-0.7). Finally, 20-m curve sprint negatively correlated with right (P=0.0021, R=-0.7) and left (P<0.0001, R=-0.9) THD and 1 RM right (P=0.025, R=-0.6;) and left (P=0.0049, R=-0.7) BSS, respectively.
Conclusions:
This pilot study demonstrated that 20-m curve sprint was negatively associated with body mass, BMI, vertical jump performance, THD and 1RM BSS. This information could be useful to coaches and sport scientists as a reference value to improve athlete performance for 200- and 400-m athletes.
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The recent and rapid developments in track spike innovation have been followed by a wave of record-breaking times and top performances. This has led many to question what role “super spikes” play in improving running performance. To date, the specific contributions of new innovations in footwear, including lightweight, resilient, and compliant midsole foam, altered geometry, and increased longitudinal bending stiffness, to track running performance are unknown. Based on current literature, we speculate about what advantages these features provide. Importantly, the effects of super spikes will vary based on several factors including the event (e.g., 100 m vs. 10,000 m) and the characteristics of the athlete wearing them. Further confounding our understanding of super spikes is the difficulty of testing them. Unlike marathon shoes, testing track spikes comes with a unique challenge of quantifying the metabolic energy demands of middle-distance running events, which are partly anaerobic. Quantifying the exact benefits from super spikes is difficult and we may need to rely on comparison of track performances pre- and post- the introduction of super spikes.
This study aimed to address the effects of increased longitudinal bending stiffness (LBS) on running economy (RE) and running biomechanics. A systematic search on four electronic databases (Pubmed, WOS, Medline and Scopus) was conducted on 26 May 2021. Twelve studies met the inclusion criteria and were included. Standardised mean difference with 95% confidence intervals (CI) between footwear with increased LBS vs. non-increased LBS conditions and effect sizes were calculated. To assess the potential effects of moderator variables (type and length plate, increased LBS, shoe mass and running speed) on the main outcome variable (i.e. RE), subgroup analyses were performed. Increased LBS improved RE (SMD = -0.43 [95% CI -0.58, -0.28], Z = 5.60, p < 0.001) compared to non-increased LBS. Significant increases of stride length (SMD = 0.29 [95% CI 0.10, 0.49], Z = 2.93, p = 0.003) and contact time (SMD = 0.17 [95% CI 0.03, 0.31], Z = 2.32, p = 0.02) were found when LBS was increased. RE improved to a greater degree at higher running speeds with footwear with increased LBS. RE improved 3.45% with curve plate compared to no-plate condition without improvements with flat plate shoes. When shoe mass was matched between footwear with increased LBS vs. non-increased LBS conditions, RE improved (3.15%). However, when shoe mass was not controlled (experimental condition with ∼35 grams extra), a significant small improvement was found. These RE improvements appear along with an increase of stride length and contact time. Shoe mass, type of plate (flat or curve) and running speed should be taken into consideration when designing a shoe aimed at improving long-distance running performance.
Objective:
To determine the independent effect of the curved carbon-fiber plate in the Nike Vaporfly 4% shoe on running economy and running biomechanics.
Methods:
Fifteen healthy male runners completed a metabolic protocol and a biomechanics protocol. In both protocols participants wore 2 different shoes, an intact Nike Vaporfly 4% (VFintact) and a cut Nike Vaporfly 4% (VFcut). The VFcut had 6 medio-lateral cuts through the carbon-fiber plate in the forefoot to reduce the effectiveness of the plate. In the metabolic protocol, participants ran at 14 km/h for 5 min, twice with each shoe, on a force-measuring treadmill while we measured metabolic rate. In the biomechanics protocol, participants ran across a runway with embedded force plates at 14 km/h. We calculated running economy, kinetics, and lower limb joint mechanics.
Results:
Running economy did not significantly differ between shoe conditions (on average, 0.55% ± 1.77% (mean ± SD) worse in the VFcut compared to the VFintact; 95% confidence interval: (-1.44% to 0.40%)). Biomechanical differences were only found in the metatarsophalangeal joint (MTP) with increased MTP dorsiflexion angle, angular velocity, and negative power in the VFcut. Contact time was 1% longer in the VFintact.
Conclusion:
Cutting the carbon-fiber plate and reducing the longitudinal bending stiffness did not have a significant effect on the energy savings in the Nike Vaporfly 4%. This suggests that the plate's stiffening effect on the MTP joint plays a limited role in the reported energy savings, and instead savings are likely from a combination and interaction of the foam, geometry, and plate.
The influence of advanced footwear technology (thickness of light midsole foam and rigid plate) on distance running performances was analyzed during an 8-year period. Analysis of variance was used to measure effects of time, gender, shoe technology, and East African origin on male and female top 20 or top 100 seasonal best times in 10-kilometer races, half-marathons, and marathons. In both genders and three distance-running events, seasonal best times significantly decreased from 2017, which coincided with the introduction of the advanced footwear technology in distance running. This performance improvement was of similar magnitude in both East African and non-East African elite runners. In female elite athletes, the magnitudes (from 1.7 to 2.3%) of the decrease in seasonal best times between 2016 and 2019 were significantly higher than in their male counterparts (from 0.6 to 1.5%). Analyses of variance confirmed that the adoption of the advanced footwear technology significantly improved the top 20 seasonal best times in female half marathons and marathons and male marathons, with the improvements being more pronounced in females and in long-distance running events. The adoption of this new shoe technology improved female marathon time by ~2 min and 10 s, which represents a significant increase in performance (1.7%).
In the wake of the quest to break the 2-h marathon barrier, carbon-fiber plates have become commonplace in marathon racing shoes. Despite the controversy surrounding this shoe technology, studies on the effects of increased longitudinal bending stiffness on running economy report mixed results. Here, we provide a comprehensive review of the current literature on midsole bending stiffness and carbon-fiber plates in distance running shoes, focusing on how longitudinal bending stiffness affects running energetics and lower limb mechanics. The current literature reports changes in running economy with increased longitudinal bending stiffness ranging from ~ 3% deterioration to ~ 3% improvement. In some studies, larger improvements have been observed, but often those shoes varied in many aspects, not just longitudinal bending stiffness. Biomechanically, increased longitudinal bending stiffness has the largest impact on metatarsal–phalangeal (MTP) and ankle joint mechanics. Plate location [top loaded (an insole), embedded (in between midsole foam), and bottom loaded (along the bottom of the shoe)] and geometry (flat/curved) affect joint moments and angular velocities at the MTP and ankle joint differently, which partly explains the mixed running economy results. Further research investigating how carbon-fiber plates interact with other footwear features (such as foam and midsole geometry), scaling of those with shoe size, body mass, and strike pattern, and comparing various plate placements is needed to better understand how longitudinal bending stiffness affects running economy.
Every women’s and men’s world records from 5 km to the marathon has been broken since the introduction of carbon fibre plate (CFP) shoes in 2016. This step-wise increase in performance coincides with recent advancements in shoe technology that increase the elastic properties of the shoe thereby reducing the energy cost of running. The latest CFP shoes are acknowledged to increase running economy by more than 4%, corresponding to a greater than 2% improvement in performance/run time. The recently modified rules governing competition shoes for elite athletes, announced by World Athletics, that includes sole thickness must not exceed 40 mm and must not contain more than one rigid embedded plate, appear contrary to the true essence and credibility of sport as access to this performance-defining technology becomes the primary differentiator of sporting performance in elite athletes. This is a particular problem in sports such as athletics where the primary sponsor of the athlete is very often a footwear manufacturing company. The postponement of the 2020 Summer Olympics provides a unique opportunity for reflection by the world of sport and time to commission an independent review to evaluate the impact of technology on the integrity of sporting competition. A potential solution to solve this issue can involve the reduction of the stack height of a shoe to 20 mm. This simple and practical solution would prevent shoe technology from having too large an impact on the energy cost of running and, therefore, determining the performance outcome.
Purpose
We compared running economy (RE) and 3-km time-trial (TT) variables of runners wearing Nike Vaporfly 4% (VP4), Saucony Endorphin lightweight racing flats (FLAT), and their habitual running (OWN) footwear.
Methods
Eighteen male recreational runners (mean +/− SD, age: 33.5 ± 11.9 year (mean ± standard deviation), peak oxygen uptake (VO2peak): 55.8 ± 4.4 mL/kg·min) attended 4 sessions approximately 7 days apart. The first session consisted of a VO2peak test to inform subsequent RE speeds set at 60%, 70%, and 80% of the speed eliciting VO2peak. In subsequent sessions, treadmill RE and 3-km TTs were assessed in the 3 footwear conditions in a randomized, counterbalanced crossover design.
Results
Oxygen consumption (mL/kg·min) was lesser in VP4 (from 4.3% to 4.4%, p ≤ 0.002) and FLAT (from 2.7% to 3.4%, p ≤ 0.092) vs. OWN across intensities, with a non-significant difference between VP4 and FLAT (1.0%–1.7%, p ≥ 0.292). Findings related to energy cost (W/kg) and energetics cost of transport (J/kg·m) were comparable. VP4 3-km TT performance (11:07.6 ± 0:56.6 mm:ss) was enhanced vs. OWN by 16.6 s (2.4%, p = 0.005) and vs. FLAT by 13.0 s (1.8%, p = 0.032). 3-km times between OWN and FLAT (0.5%, p = 0.747) were similar. Most runners (n = 11, 61%) ran their fastest TT in VP4.
Conclusions
Overall, VP4 improved laboratory-based RE measures in male recreational runners at relative speeds compared to OWN, but the RE improvements in VP4 were not significant vs. FLAT. More runners exhibited better treadmill TT performances in VP4 (61%) vs. FLAT (22%) and OWN (17%). The variability in RE (–10.3% to 13.3%) and TT (–4.7% to 9.3%) improvements suggests that responses to different types of shoes are individualized and warrant further investigation.
In an attempt to improve their distance-running performance, many athletes race with carbon fiber plates embedded in their shoe soles. Accordingly, we sought to establish whether, and if so how, adding carbon fiber plates to shoes soles reduces athlete aerobic energy expenditure during running (improves running economy). We tested 15 athletes as they ran at 3.5 m/s in four footwear conditions that varied in shoe sole bending stiffness, modified by carbon fiber plates. For each condition, we quantified athlete aerobic energy expenditure and performed biomechanical analyses, which included the use of ultrasonography to examine soleus muscle dynamics in vivo. Overall, increased footwear bending stiffness lengthened ground contact time (p = 0.048), but did not affect ankle (p ≥ 0.060), knee (p ≥ 0.128), or hip (p ≥ 0.076) joint angles or moments. Additionally, increased footwear bending stiffness did not affect muscle activity (all seven measured leg muscles (p ≥ 0.146)), soleus active muscle volume (p = 0.538; d = 0.241), or aerobic power (p = 0.458; d = 0.04) during running. Hence, footwear bending stiffness does not appear to alter the volume of aerobic energy consuming muscle in the soleus, or any other leg muscle, during running. Therefore, adding carbon fiber plates to shoe soles slightly alters whole-body and calf muscle biomechanics but may not improve running economy.
Eliud Kipchoge made two attempts to break the 2-hour marathon, in Monza and then Vienna. Here we analyse only the effects of course elevation profile and turn curvatures on his performances. We used publicly available data to determine the undulations in elevation and the radii of the curves on the course. With previously developed equations for the effects of velocity, slope, and curvature on oxygen uptake, we performed simulations to quantify how much the elevation changes and curves of the Vienna course affect a runner’s oxygen uptake (at a fixed velocity) or velocity (at a fixed oxygen uptake). We estimate that, after the initial downhill benefit, the course led to an overall oxygen uptake penalty of only 0.03%. When compared to a perfectly level straight course, we estimate that the combined effects of the undulations and curves of the Vienna course incurred a penalty of just 1.37 seconds. Kipchoge ran 2:00:25 in Monza Italy. Comparison with the Monza course profile indicates a 46.2 second (1.09% oxygen uptake) advantage of Vienna’s course while the fewer curves of Vienna contributed ~ 1 second. The Vienna course was very well-chosen because it minimized the negative effects of elevation changes and curves.
Abbreviations: CoT: Oxygen cost of transport; C V ˙ O2: Curved rate of oxygen consumption; V ˙ O2: Rate of oxygen consumption; WA: World Athletics
Although the role of shoe constructions on running injury and performance has been widely investigated, systematic reviews on the shoe construction effects on running biomechanics were rarely reported. Therefore, this review focuses on the relevant research studies examining the biomechanical effect of running shoe constructions on reducing running-related injury and opti-mising performance. Searches of five databases and Footwear Science from January 1994 to September 2018 for related biome-chanical studies which investigated running footwear constructions yielded a total of 1260 articles. After duplications were removed and exclusion criteria applied to the titles, abstracts and full text, 63 studies remained and categorised into following constructions: (a) shoe lace, (b) midsole, (c) heel flare, (d) heel-toe drop, (e) minimalist shoes, (f) Masai Barefoot Technologies, (g) heel cup, (h) upper, and (i) bending stiffness. Some running shoe constructions positively affect athletic performance-related and injury-related variables: 1) increasing the stiffness of running shoes at the optimal range can benefit performance-related variables ; 2) softer midsoles can reduce impact forces and loading rates; 3) thicker midsoles can provide better cushioning effects and attenuate shock during impacts but may also decrease plantar sensations of a foot; 4) minimalist shoes can improve running economy and increase the cross-sectional area and stiffness of Achilles tendon but it would increase the metatarsophalangeal and ankle joint loading compared to the conventional shoes. While shoe constructions can effectively influence running bio-mechanics, research on some constructions including shoe lace, heel flare, heel-toe drop, Masai Barefoot Technologies, heel cup, and upper requires further investigation before a viable scientific guideline can be made. Future research is also needed to develop standard testing protocols to determine the optimal stiffness, thickness, and heel-toe drop of running shoes to optimise performance related variables and prevent running-related injuries.
In my opinion there is insufficient scientific evidence to support a proposal to regulate the stack
height of road racing shoes to avoid an unfair advantage. The available evidence suggests that measurable differences in running economy attributable to footwear, at least at this point in time,
should be viewed in a strictly comparative context that is limited to head-to-head comparisons between the shoes used in the study and should not be treated as evidence of a more universal and broadly predictable outcome due to stack height or any other single feature.
The changes in running biomechanics induced by an increased longitudinal bending stiffness (stiff plates added into the shoes) have been well investigated, but little is known concerning the effects of the stiff plate location into the shoe on running biomechanics. Fourteen male recreational runners ran at two participant-specific running speeds (3.28 ± 0.28 m/s and 4.01 ± 0.27 m/s) with two shoe conditions where a stiff plate was added either in high (under the insole) or low location (between the midsole and outsole). Ground reaction forces, lower limb joint angles, net joint torques and work, as well as alignment between the resultant ground reaction force and the leg were analysed. Among the running speeds performed by the runners, the high location significantly decreased propulsive ground reaction forces, increased metatarsophalangeal joint dorsiflexion and ankle plantarflexion, induced an increased alignment between the resultant ground reaction force and the runner’s leg, thus decreasing all the lower limb joint torques and the positive work at the knee joint compared to the low location. The results suggested that the high stiff plate location into the shoe should be considered for running performance perspectives, but care should be taken to not alter the perceived comfort and/or increase injury risks.
Training, footwear, nutrition, and racing strategies (i.e., drafting) have all been shown to reduce the metabolic cost of distance running (i.e., improve running economy). However, how these improvements in running economy (RE) quantitatively translate into faster running performance is less established. Here, we quantify how metabolic savings translate into faster running performance, considering both the inherent rate of oxygen uptake-velocity relation and the additional cost of overcoming air resistance when running overground. We collate and compare five existing equations for oxygen uptake-velocity relations across wide velocity ranges. Because the oxygen uptake vs. velocity relation is non-linear, for velocities slower than ∼3 m/s, the predicted percent improvement in velocity is slightly greater than the percent improvement in RE. For velocities faster than ∼3 m/s, the predicted percent improvement in velocity is less than the percent improvements in RE. At 5.5 m/s, i.e., world-class marathon pace, the predicted percent improvement in velocity is ∼2/3rds of the percent improvement in RE. For example, at 2:04 marathon pace, a 3% improvement in RE translates to a 1.97% faster velocity or 2:01:36, almost exactly equal to the recently set world record.
Purpose
This study focused on the effects of shoe energy return and shoe longitudinal bending stiffness on the energetic cost and biomechanics of running.
Methods
The energetic cost of running and biomechanical variables altering running economy (ground contact times, stride frequency, vertical and leg stiffness, ground reaction force impulses, alignment between the resultant ground reaction force and the leg) were measured for nineteen male recreational runners. Participants ran overground under their ventilatory anaerobic threshold (10.8 ± 1.1 km h⁻¹ on average) using four shoe prototypes with features combining low or high magnitudes of energy return and longitudinal bending stiffness.
Results
Neither the energy return, nor the longitudinal bending stiffness, or the interaction of these shoe features altered the energetic cost of running. High energy return shoes induced significant increased ground contact time from 274.5 ± 18.3 to 277.1 ± 18.7 ms, and significant decreased stride frequency from 1.34 ± 0.05 to 1.33 ± 0.05 Hz. High bending stiffness shoes induced significant increased ground contact time from 273.8 ± 18.2 to 277.9 ± 18.7 ms, significant increased vertical stiffness from 23.2 ± 3.4 to 23.8 ± 3.0 kN m⁻¹, and significant decreased net vertical impulse from 245.4 ± 17.2 to 241.7 ± 17.5 BW ms.
Conclusions
Increased energy return and longitudinal bending stiffness induced subtle changes in the running biomechanics, but did not induce any decrease in the energetic cost of running.
Background
We have shown that a prototype marathon racing shoe reduced the metabolic cost of running for all 18 participants in our sample by an average of 4%, compared to two well-established racing shoes. Gross measures of biomechanics showed minor differences and could not explain the metabolic savings.
Objective
To explain the metabolic savings by comparing the mechanics of the shoes, leg, and foot joints during the stance phase of running.
Methods
Ten male competitive runners, who habitually rearfoot strike ran three 5-min trials in prototype shoes (NP) and two established marathon shoes, the Nike Zoom Streak 6 (NS) and the adidas adizero Adios BOOST 2 (AB), at 16 km/h. We measured ground reaction forces and 3D kinematics of the lower limbs.
Results
Hip and knee joint mechanics were similar between the shoes, but peak ankle extensor moment was smaller in NP versus AB shoes. Negative and positive work rates at the ankle were lower in NP shoes versus the other shoes. Dorsiflexion and negative work at the metatarsophalangeal (MTP) joint were reduced in the NP shoes versus the other shoes. Substantial mechanical energy was stored/returned in compressing the NP midsole foam, but not in bending the carbon-fiber plate.
Conclusion
The metabolic savings of the NP shoes appear to be due to: (1) superior energy storage in the midsole foam, (2) the clever lever effects of the carbon-fiber plate on the ankle joint mechanics, and (3) the stiffening effects of the plate on the MTP joint.
Background
Running economy represents a complex interplay of physiological and biomechanical factors that are able to adapt chronically through training, or acutely through other interventions such as changes in footwear. The Nike Vaporfly (NVF) shoe was designed for marathon running on the roads and has been shown to improve running economy by ~ 4% compared with other marathon shoes, however, during track racing, distance runners traditionally wear a much lighter shoe with an embedded spike plate around the forefoot.
Objective
The aim of this study was to determine if, and to what extent, the NVF shoes improve running economy compared with established track spikes (Nike Zoom Matumbo 3 [NZM]) and marathon racing shoes (Adidas Adizero Adios 3 [ADI]).
Methods
Twenty-four highly-trained runners (12 male, 12 female) ran 4 × 5 min trials on a treadmill while wearing each of the four shoe conditions: NVF, NZM, ADI, and the NVF matched in weight to the ADI shoe (NVF +), during three separate visits—visit 1: familiarization; visit 2: 14 and 18 km·h⁻¹ for men, 14 and 16 km·h⁻¹ for women; visit 3: 16 km·h⁻¹ for men, 15 km·h⁻¹ for women, plus a maximal rate of oxygen uptake (VO2max) test for both sexes. We measured the rates of oxygen uptake (VO2), carbon dioxide production and biomechanical measures while running at each velocity and shoe condition.
Results
The NVF shoe improved running economy by 2.6 ± 1.3% compared with the NZM, 4.2 ± 1.2% compared with ADI, and 2.9 ± 1.3% when matched in weight of the ADI shoe. Among the 24 subjects, the difference in running economy over the four velocities between the NVF and NZM shoes ranged from + 0.50 to − 5.34%, and − 1.72 to − 7.15% for NVF versus ADI. Correlations between changes in running economy and changes in biomechanical variables were either trivial or small, but unclear.
Conclusion
The NVF enhanced running economy compared with track spikes and marathon shoes, and should be considered a viable shoe option for track and road racing.
The cost of generating force hypothesis proposes that the metabolic rate during running is determined by the rate of muscle force development (1/tc, tc=contact time) and the volume of active leg muscle. A previous study assumed a constant recruited muscle volume and reported that the rate of force development alone explained ∼70% of the increase in metabolic rate for human runners across a moderate velocity range (2-4 m s-1). We hypothesized that over a wider range of velocities, the effective mechanical advantage (EMA) of the lower limb joints would overall decrease, necessitating a greater volume of active muscle recruitment. Ten high-caliber male human runners ran on a force-measuring treadmill at 8, 10, 12, 14, 16 and 18 km hr-1 while we analyzed their expired air to determine metabolic rates. We measured ground reaction forces and joint kinematics to calculate contact time and estimate active muscle volume. From 8 to 18 km hr-1, metabolic rate increased 131% from 9.28 to 21.44 W kg-1 Contact time (tc) decreased from 0.280 sec to 0.190 sec, and thus the rate of force development (1/tc) increased by 48%. Ankle EMA decreased by 19.7±11%, knee EMA increased by 11.1±26.9% and hip EMA decreased by 60.8±11.8%. Estimated active muscle volume per leg increased 52.8% from 1663±152 cm3 to 2550±169 cm3 Overall, 98% of the increase in metabolic rate across the velocity range was explained by just two factors: the rate of generating force and the volume of active leg muscle.
Background
Reducing the energetic cost of running seems the most feasible path to a sub-2-hour marathon. Footwear mass, cushioning, and bending stiffness each affect the energetic cost of running. Recently, prototype running shoes were developed that combine a new highly compliant and resilient midsole material with a stiff embedded plate. Objective
The aim of this study was to determine if, and to what extent, these newly developed running shoes reduce the energetic cost of running compared with established marathon racing shoes. Methods18 high-caliber athletes ran six 5-min trials (three shoes × two replicates) in prototype shoes (NP), and two established marathon shoes (NS and AB) during three separate sessions: 14, 16, and 18 km/h. We measured submaximal oxygen uptake and carbon dioxide production during minutes 3–5 and averaged energetic cost (W/kg) for the two trials in each shoe model. ResultsCompared with the established racing shoes, the new shoes reduced the energetic cost of running in all 18 subjects tested. Averaged across all three velocities, the energetic cost for running in the NP shoes (16.45 ± 0.89 W/kg; mean ± SD) was 4.16 and 4.01% lower than in the NS and AB shoes, when shoe mass was matched (17.16 ± 0.92 and 17.14 ± 0.97 W/kg, respectively, both p < 0.001). The observed percent changes were independent of running velocity (14–18 km/h). Conclusion
The prototype shoes lowered the energetic cost of running by 4% on average. We predict that with these shoes, top athletes could run substantially faster and achieve the first sub-2-hour marathon.
A sub-2-hour marathon requires an average velocity (5.86 m/s) that is 2.5% faster than the current world record of 02:02:57 (5.72 m/s) and could be accomplished with a 2.7% reduction in the metabolic cost of running. Although supporting body weight comprises the majority of the metabolic cost of running, targeting the costs of forward propulsion and leg swing are the most promising strategies for reducing the metabolic cost of running and thus improving marathon running performance. Here, we calculate how much time could be saved by taking advantage of unconventional drafting strategies, a consistent tailwind, a downhill course, and specific running shoe design features while staying within the current International Association of Athletic Federations regulations for record purposes. Specifically, running in shoes that are 100 g lighter along with second-half scenarios of four runners alternately leading and drafting, or a tailwind of 6.0 m/s, combined with a 42-m elevation drop could result in a time well below the 2-hour marathon barrier.
Purpose:
Our goal was to quantify if small (1 - 3%) changes in running economy quantitatively affect distance-running performance. Based on the linear relationship between metabolic rate and running velocity and on earlier observations that added shoe mass increases metabolic rate by ~1% per 100 grams per shoe, we hypothesized that adding 100 and 300 grams per shoe would slow 3,000m time-trial performance by 1% and 3%, respectively.
Methods:
18 male, sub-20 minute 5km runners completed treadmill testing, and three 3,000m time-trials wearing control shoes and identical shoes with 100 and 300 grams of discreetly added mass. We measured rates of oxygen consumption and carbon dioxide production and calculated metabolic rates for the treadmill tests and we recorded overall running time for the time-trials.
Results:
Adding mass to the shoes significantly increased metabolicrate at 3.5 m·s by 1.11% per 100grams per shoe (95% CI: 0.88-1.35%). While wearing the control shoes, participants ran the 3,000m time-trial in 626.1 ± 55.6s. Times averaged 0.65 ± 1.36% and 2.37 ± 2.09% slower for the +100g and +300g shoes respectively (p<0.001). Based on a linear fit of all the data, 3,000m time increased 0.78% per added 100 grams per shoe (95% CI: 0.52-1.04%).
Conclusion:
Adding shoe mass predictably degrades running economy and slows 3,000m time-trial performance proportionally. Our data demonstrate that laboratory-based running economy measurements can accurately predict changes in distance running race performance due to shoe modifications.
Running economy (RE) has a strong relationship with running performance, and modifiable running biomechanics are a determining factor of RE. The purposes of this review were to (1) examine the intrinsic and extrinsic modifiable biomechanical factors affecting RE; (2) assess training-induced changes in RE and running biomechanics; (3) evaluate whether an economical running technique can be recommended and; (4) discuss potential areas for future research. Based on current evidence, the intrinsic factors that appeared beneficial for RE were using a preferred stride length range, which allows for stride length deviations up to 3 % shorter than preferred stride length; lower vertical oscillation; greater leg stiffness; low lower limb moment of inertia; less leg extension at toe-off; larger stride angles; alignment of the ground reaction force and leg axis during propulsion; maintaining arm swing; low thigh antagonist–agonist muscular coactivation; and low activation of lower limb muscles during propulsion. Extrinsic factors associated with a better RE were a firm, compliant shoe–surface interaction and being barefoot or wearing lightweight shoes. Several other modifiable biomechanical factors presented inconsistent relationships with RE. Running biomechanics during ground contact appeared to play an important role, specifically those during propulsion. Therefore, this phase has the strongest direct links with RE. Recurring methodological problems exist within the literature, such as cross-comparisons, assessing variables in isolation, and acute to short-term interventions. Therefore, recommending a general economical running technique should be approached with caution. Future work should focus on interdisciplinary longitudinal investigations combining RE, kinematics, kinetics, and neuromuscular and anatomical aspects, as well as applying a synergistic approach to understanding the role of kinetics.
Although track and field spike shoes are crafted for runners, these shoes are not designed for regular walking. With such shoes, runners may eventually encounter serious chronic injuries such as plantar fasciitis, shin splints, achilles tendinitis, chondromalacia, and iliotibial band syndrome. To address this problem, a modified spike shoe was tested and compared to a regular spike shoe. The modification consists of adding a removable heel to the shoe sole in order to reduce the flexion of the foot and properly level the foot for walking. Nine healthy participants performed walking drills at 2 and 3 mph, using the original and the modified shoes. Electromyography (EMG) measurements were used to evaluate muscle activities. Participants also rated their discomfort on a 0-10 scale. Results show that the use of modified shoes resulted in a reduction of 22% and 24.25% EMG activity for the tibialis and gastrocnemius muscles, respectively. Comfort ratings increased by an average of 2.7, 2.6, 3.9, and 4.2 points at the knees, calves, ankles, and feet, respectively.
Running economy (RE) is considered an important physiological measure for endurance athletes, especially distance runners. This review considers 1) how RE is defined and measured and 2) physiological and biomechanical factors that determine or influence RE. It is difficult to accurately ascertain what is good, average, and poor RE between athletes and studies due to variation in protocols, gas-analysis systems, and data averaging techniques. However, representative RE values for different caliber of male and female runners can be identified from existing literature with mostly clear delineations in oxygen uptake across a range of speeds in moderately and highly trained and elite runners. Despite being simple to measure and acceptably reliable, it is evident that RE is a complex, multifactorial concept that reflects the integrated composite of a variety of metabolic, cardiorespiratory, biomechanical and neuromuscular characteristics that are unique to the individual. Metabolic efficiency refers to the utilization of available energy to facilitate optimal performance, whereas cardiopulmonary efficiency refers to a reduced work output for the processes related to oxygen transport and utilization. Biomechanical and neuromuscular characteristics refer to the interaction between the neural and musculoskeletal systems and their ability to convert power output into translocation and therefore performance. Of the numerous metabolic, cardiopulmonary, biomechanical and neuromuscular characteristics contributing to RE, many of these are able to adapt through training or other interventions resulting in improved RE.
Background:
The effect of footwear on running economy has been investigated in numerous studies. However, no systematic review and meta-analysis has synthesised the available literature and the effect of footwear on running performance is not known.
Objective:
The aim of this systematic review and meta-analysis was to investigate the effect of footwear on running performance and running economy in distance runners, by reviewing controlled trials that compare different footwear conditions or compare footwear with barefoot.
Methods:
The Web of Science, Scopus, MEDLINE, CENTRAL (Cochrane Central Register of Controlled Trials), EMBASE, AMED (Allied and Complementary Medicine), CINAHL and SPORTDiscus databases were searched from inception up until April 2014. Included articles reported on controlled trials that examined the effects of footwear or footwear characteristics (including shoe mass, cushioning, motion control, longitudinal bending stiffness, midsole viscoelasticity, drop height and comfort) on running performance or running economy and were published in a peer-reviewed journal.
Results:
Of the 1,044 records retrieved, 19 studies were included in the systematic review and 14 studies were included in the meta-analysis. No studies were identified that reported effects on running performance. Individual studies reported significant, but trivial, beneficial effects on running economy for comfortable and stiff-soled shoes [standardised mean difference (SMD) <0.12; P < 0.05), a significant small beneficial effect on running economy for cushioned shoes (SMD = 0.37; P < 0.05) and a significant moderate beneficial effect on running economy for training in minimalist shoes (SMD = 0.79; P < 0.05). Meta-analysis found significant small beneficial effects on running economy for light shoes and barefoot compared with heavy shoes (SMD < 0.34; P < 0.01) and for minimalist shoes compared with conventional shoes (SMD = 0.29; P < 0.01). A significant positive association between shoe mass and metabolic cost of running was identified (P < 0.01). Footwear with a combined shoe mass less than 440 g per pair had no detrimental effect on running economy.
Conclusions:
Certain models of footwear and footwear characteristics can improve running economy. Future research in footwear performance should include measures of running performance.
Purpose: Several studies have investigated whether shoe cushioning properties have an effect on running economy. However, the findings have not been unanimous. Studies have shown both increases and decreases in running economy with soft shoes, while other studies have shown participant specific differences. Therefore, the purpose of this study was to add to the body of knowledge describing the effects of shoe cushioning properties on running economy.Methods: This study was comprised of two experiments; one using a stationary metabolic analysis system to measure oxygen consumption during treadmill running, and one using a portable metabolic analysis system to measure oxygen consumption during over-ground running. Twelve aerobically fit athletes participated in each experiment. Two professionally constructed pairs of prototype running shoes were provided by adidas AG for this experiment (Soft shoe and Control shoe). The shoes were identical in construction with the only differences being the midsole material and corresponding stiffness and energy return.Results: For both the treadmill and over-ground experiments, the Soft shoe condition was associated with statistically significantly decreased oxygen consumption compared to the Control shoe condition (Treadmill p = 0.044, Over-ground p = 0.028). In the treadmill experiment, 10 of the 12 subjects consumed less oxygen while wearing the more compliant/resilient condition, with an average decrease for all subjects of 1.0%. In the over-ground experiment 9 of the 12 subjects consumed less oxygen while running in the more compliant/resilient condition, with an average decrease for all subjects of 1.2%.Conclusion: Running shoes with softer and more resilient midsoles were found to influence running economy by 1.0% on average during treadmill and over-ground experiments.
This study aimed to investigate the effects of surface and shoe cushioning on the metabolic cost of running. In running, the leg muscles generate force to cushion the impact with the ground. External cushioning (surfaces or shoes) may reduce the muscular effort needed for cushioning and thus reduce metabolic cost. Our primary hypothesis was that the metabolic cost of unshod running would decrease with a more cushioned running surface. We also hypothesized that because of the counteracting effects of shoe cushioning and mass, unshod running on a hard surface would have approximately the same metabolic cost as running in lightweight, cushioned shoes.
To test these hypotheses, we attached 10- and 20-mm-thick slats of the same foam cushioning used in running shoe midsoles to the belt of a treadmill that had a rigid deck. Twelve subjects who preferred a midfoot strike pattern and had substantial barefoot/minimalist running experience ran without shoes on the normal treadmill belt and on each thickness of foam. They also ran with lightweight, cushioned shoes on the normal belt. We collected V˙O2 and V˙CO2 to calculate the metabolic power demand and used a repeated-measures ANOVA to compare between conditions.
Compared to running unshod on the normal belt, running unshod on the 10-mm-thick foam required 1.63% ± 0.67% (mean ± SD) less metabolic power (P = 0.034) but running on the 20-mm-thick foam had no significant metabolic effect. Running with and without shoes on the normal belt had similar metabolic power demands, likely because the beneficial energetic effects of cushioning counterbalanced the detrimental effects of shoe mass.
On average, surface and shoe cushioning reduce the metabolic power required for submaximal running.
Longitudinal midsole bending stiffness and elasticity are two critical features in the construction of running shoes. Stiff elastic materials (eg, carbon fiber) can be used to alter the midsole bending behavior. The purpose of this study was to investigate the effects of midsole stiffness and elasticity manipulation on metatarsophalangeal (MTP) joint mechanics during running in 19 male subjects at 3.5 m/s. Midsole bending stiffness and elasticity were modified by means of carbon fiber insoles of varying thickness. Stiffening the shoe structures around the MTP joint caused a shift of the point of force application toward the front edge of the shoe-ground interface. Negative work was significantly reduced for the stiffest shoe condition and at the same time a significant increase of positive work at the MTP joint was found. It seems plausible that the increase in positive work originates from the reutilization of elastic energy that was stored inside the passive elastic structures of the shoe and toe flexing muscle tendon units. Further, an increase in midsole longitudinal bending stiffness seems to alter the working conditions and mechanical power generation capacities of the MTP plantar flexing muscle tendon units by changing ground reaction force leverage and MTP angular velocity.
Various shoes are worn by distance runners throughout a training season. This study measured the differences in ground reaction forces between running shoes, racing flats, and distance spikes in order to provide information about the potential effects of footwear on injury risk in highly competitive runners. Ten male and ten female intercollegiate distance runners ran across a force plate at 6.7 m·s -1 (for males) and 5.7 m·s -1 (for females) in each of the three types of shoes. To control for differences in foot strike, only subjects who exhibited a heel strike were included in the data analysis. Two repeated-measures ANOVAs with Tukey's post-hoc tests (p < 0.05) were used to detect differences in shoe types among males and females. For the males, loading rate, peak vertical impact force and peak braking forces were significantly greater in flats and spikes compared to running shoes. Vertical stiffness in spikes was also significantly greater than in running shoes. Females had significantly shorter stance times and greater maximum propulsion forces in racing flats compared to running shoes. Changing footwear between the shoes used in this study alters the loads placed on the body. Care should be taken as athletes enter different phases of training where different footwear is required. Injury risk may be increased since the body may not be accustomed to the differences in force, stance time, and vertical stiffness.
We conducted an exploratory analysis to compare running kinematics of 16 male recreational runners wearing Nike Vaporfly 4% (VP4), Saucony Endorphin racing flat (FLAT), and their habitual (OWN) footwear. We also explored potential relationships between kinematic and physiological changes. Runners (age: 33 ± 12 y, V˙ O2peak: 55.2 ± 4.3 ml · kg-1·min-1) attended 3 sessions after completing an V˙ O2peak test in which sagittal plane 3D kinematics at submaximal running speeds (60%, 70% and 80% ʋ V˙ O2peak) were collected alongside economy measures. Kinematics were compared using notched boxplots, and between-shoe kinematic differences were plotted against between-shoe economy differences. Across intensities, VP4 involved longer flight times (6.7 to 10.0 ms) and lower stance hip range of motion (~3°), and greater vertical pelvis displacement than FLAT (~0.4 cm). Peak dorsiflexion angles (~2°), ankle range of motion (1.0° to 3.9°), and plantarflexion velocities (11.3 to 89.0 deg · sec-1) were greatest in FLAT and lowest in VP4. Foot-ground angles were smaller in FLAT (2.5° to 3.6°). Select kinematic variables were moderately related to economy, with higher step frequencies and longer step lengths in VP4 and FLAT associated with improved economy versus OWN. Footwear changes from OWN altered running kinematics. The most pronounced differences were observed in ankle, spatiotemporal, and foot-ground angle variables.
Recent advancements in running shoe technology, particularly in the Nike Vaporfly, have been shown to improve running economy. Other brands have now also developed new, advanced shoes with thicker midsole foams intended to be more compliant and resilient, along with a carbon-fibre plate. However, none of these new shoes have been compared to the Vaporfly in terms of running economy. Therefore, we compared running economy among seven different highly cushioned racing shoes with a carbon plate: Hoka Rocket X (Hoka RX), Saucony Endorphin Pro (Saucony EP), Nike Alphafly (Nike AF), Asics Metaspeed Sky (Asics MS), Nike Vaporfly Next % 2 (Nike VF2), New Balance RC Elite (New Bal RC), Brooks Hyperion Elite 2 (Brooks HE2) and 1 traditional racing shoe: Asics Hyperspeed (Asics HS) in twelve male runners (5k best: 16.0 ± 0.7 min) during two lab visits. Shoes were tested in a random sequence over 8 × 5-min trials (16 km·h⁻¹; 5-min rest between trials) on visit 1, and in the reverse/mirrored order for visit 2. Metabolic and running mechanics data were collected and averaged across visits. V̇O2 (ml·kg⁻¹·min⁻¹; % change from Asics HS) was significantly different across shoes. Hoka RX (51.67 ± 2.07) and Brooks HE2 (51.42 ± 1.72) did not differ from Asics HS (51.71 ± 2.02). While Saucony EP (50.93 ± 1.82; −1.48 ± 0.72%) and New Bal RC (50.99 ± 1.83; −1.37 ± 0.78%) were statistically better than Asics HS, they were inferior to Nike AF (50.13 ± 1.86; −3.03 ± 1.48%), Nike VF2 (50.29 ± 1.72; −2.72 ± 1.02%), and Asics MS (50.39 ± 1.71; −2.52 ± 1.08%). From these data, it appears most running shoe companies have not yet caught up to the advantages conferred by the Nike VF2.
There is scientific and legal controversy about recent technological advances in performance running shoes that reduce the energetic cost of running and may provide a distinct competitive advantage. To better understand the potential performance-enhancing effects of technological advancements in marathon racing shoes, we examined the finishing times and racing shoes of the top 50 male and 50 female runners from the World Marathon Major series in the 2010s - before and after the introduction of new Nike shoe models (4%, NEXT%, Alphafly, and other prototypes; herein referred to as neoteric Nikes). Data for racing shoes were available for 3,886 of the 3,900 performances recorded at the four annual marathons in Boston, London, Chicago, and New York. In full cohort analyses, marathon finishing times were 2.0% or 2.8 min (138.5±8.1 min vs. 141.3±7.4 min, P<0.001) faster for male runners wearing neoteric Nikes compared to other shoes. For females, marathon finishing times were 2.6% or 4.3 min (159.1±10.0 min vs. 163.4±10.7 min, P<0.001) faster for runners wearing neoteric Nikes. In a subset of within-runner changes in marathon performances (males, n = 138; females, n = 101), marathon finishing times improved by 0.8% or 1.2 min for males wearing neoteric Nikes relative to the most recent marathon in which other shoes were worn, and this performance-enhancing effect was greater among females who demonstrated 1.6% or 3.7 min improvement (P=0.002). Our results demonstrate that marathon performances are substantially when world-class athletes, and particularly females, wear marathon racing shoes with technological advancements.
Increasing the longitudinal bending stiffness of running shoes decreases energy cost until a low point is reached, suggesting an optimal shoe stiffness. Previous research found optimal stiffness varies among individuals, however, none has determined the causes of variation both between individuals and running speeds. The primary purpose of this study was to understand how optimal shoe stiffness is affected by running speed. A secondary purpose examined the anatomical and biomechanical characteristics associated with optimal stiffness variation. Six shoe stiffness conditions were manufactured with a carbon fibre plate between the midsole and outsole of a standard running shoe. Twenty-one male runners (mass = 67.1 ± 5.0 kg, height = 178.9 cm ± 4.0 cm, age = 26.4 ± 8.4 years) completed testing at 2.98 m/s and 4.47 m/s in all shoe conditions, measuring metabolic cost, and several biomechanical and anatomical variables. Data were separated by foot strike. At the fast speed, average optimal stiffness was 19.29 ± 5.62 N/mm with a metabolic benefit of 3.02 ± 2.62%. Slow speed average optimal stiffness was 17.04 ± 6.09 N/mm with a metabolic benefit of 1.93 ± 1.82%. Only rearfoot strikers demonstrated a significant increase in optimal stiffness (p = .04) across speeds. There were no correlations between any of the measured anatomical or biomechanical variables and optimal stiffness. Optimal stiffness varied between subjects but was not correlated to any of our measured characteristics. Rearfoot striking runners may benefit from a higher stiffness shoe at faster speeds to enable optimal performance.
The primary footwear components of interest to improve performance are midsole material, weight, and longitudinal bending stiffness. Little is known about the effects of varied longitudinal bending stiffness across a range of running speeds. The purpose of this study was to identify changes in spatiotemporal variables, horizontal ground reaction forces, subjective comfort, and metabolic cost at different running speeds in response to varied longitudinal bending stiffness. Ten highly trained males ran at 14, 17 and 20 km/h in shoes with varying longitudinal bending stiffness (normal 5.9, stiff 10.5 and very stiff 17.0 N-m/rad). Ground reaction forces, metabolics and subjective comfort assessments were collected. There were significant changes (p < .05) in contact time, stride frequency, and stride length between shoe conditions at all three speeds. Peak propulsive force decreased with increased bending stiffness at all three speeds, but there was no change in braking or propulsive impulse. The patterns of changes in stride length and stride frequency were different between speeds. At 14 km/h, most participants elicited a minimum metabolic rate in the normal shoe. However, at 17 km/h an increased number of participants were more economical in the stiff shoe, despite it weighing an extra 50 g compared to the normal shoe. Running speed had an influence on subjective comfort, with participants tending to prefer the normal shoe at 14 km/h and the stiff shoe at 17 km/h. These results suggest that an optimal bending stiffness to reduce metabolic cost and improve comfort may be running speed dependent.
The choice of marathon racing shoes can greatly affect performance. The purpose of this study is to metabolically and mechanically compare the consumer version of the Nike Vaporfly 4% shoe to two other popular marathon shoes, and determine differences in running economy. Nineteen subjects performed two 5-minute trials at 4.44m/s wearing the Adidas Adios Boost (AB), Nike Zoom Streak (ZS), and Nike Vaporfly 4% (VP) in random order. Oxygen uptake was recorded during minutes 3–5 and averaged across both shoe trials. On a second day, subjects wore reflective markers, and performed a 3-minute trial in each shoe. Motion and force data were collected over the final 30 seconds of each trial. VP oxygen uptake was 2.8% and 1.9% lower than the AB and ZS. Stride length, plantar flexion velocity, and center of mass vertical oscillation were significantly different in the VP. The percent benefit of the VP over AB shoe was predicted by subject ground time. These results indicate that use of the VP shoe results in improved running economy, partially due to differences in running mechanics. Subject variation in running economy improvement is only partially explained by variation in ground time.
Background:
This study investigated the influence of shoe sole bending stiffness on sprint performance, in relation to anthropometric and strength-power capability characteristics of sprinters.
Methods:
Seventeen male athletes performed three maximal effort 60-m sprints using spiked-shoes with different bending stiffness sole. Sprint times during 60-m sprint, anthropometry and strength-power capabilities represented by maximum toe-flexor test and rebound continuous ankle jump of athletes were measured.
Results:
The sprint times did not differ when shoe sole bending stiffness was altered by carbon fiber plates (CFPs) of 13.4 and 37.1 N/mm. The optimal bending stiffness for the fastest sprint was not associated with any anthropometric and strength-power variables. As results of stepwise-multiple-regression analyses, however, the left maximum toe-flexor strength and contact time and jump height of rebound continuous ankle jump for a 0-30-m section with CFP of 13.4 N/mm, body mass for a 0-30-m section with CFP of 37.1 N/mm, and the left maximum toe-flexor strength for a 30-60-m section with CFP of 37.1 N/mm were selected as predictors of changes in sprint times with stiffer sole shoes.
Conclusions:
These results indicate that, although sole bending stiffness of spiked-shoe may not affect the sprinting performance on average, changes in sprint time by the use of stiffer sole spiked-shoe for individuals will be predicted by toe-flexor strength, rebound continuous ankle jump performance, and body mass. The findings obtained here can be useful information for sprinters and coaches to choose the spiked shoe with an appropriate bending stiffness of sole for individuals.
Longitudinal bending stiffness (LBS) of footwear has been shown to affect performance in jumping and sprinting tasks. A detailed description of the mechanisms underlying these performance alterations is lacking in the literature at the moment. Therefore, the purpose of this study is to describe why performance in a linear acceleration task is affected by LBS. Fifteen male athletes were analysed using full-body motion analysis combined with ground reaction force (GRF) measurements during the first step of a full effort 5 m sprint in a low stiffness baseline (BL), medium stiffness (MS) and high stiffness (HS) condition. A significant reduction in acceleration performance (−6.3%) was found in the HS condition compared to BL. Changes in acceleration performance in MS and HS were related to altered contact times, ground force application and overall body orientation, but not to alterations in energy absorption at the metatarsal phalangeal (MTP) joint. A gearing function of LBS was evident from increased MTP and ankle joint GRF lever arms, which might offer a potential to improve the effectiveness of horizontal force application. Nonetheless, athletes in this study were not using this potential to improve acceleration performance, possibly due to missing strength capacities. The results of this study indicate that high LBS might lead to reduced acceleration performance in athletes lacking the capacities to make use of the gearing function of footwear LBS. Footwear studies need to address the interrelationship between LBS, individual strength capacities, average ground force application and its effectiveness during acceleration tasks in the future.
Previous research has shown that altering forefoot (FF) bending stiffness can enhance running economy; however, the mechanism behind the changes in running economy remains unknown. Therefore, the purpose of this study was to investigate the relationship between forefoot bending stiffness, running economy, and lower limb kinematics during overground running. Eighteen aerobically fit recreational male athletes performed overground running using a portable metabolic analysis system to measure oxygen consumption in two footwear conditions with different forefoot bending stiffness. Sagittal plane kinematic data of the metatarsophalangeal, ankle, and knee joints were recorded using a high-speed camera. On average, there was no difference in running economy when running in the Stiff shoe (O2 = 38.1 ± 5.4 mL/kg/min) compared to the Control shoe (O2 = 37.7 ± 5.8 mL/kg/min, p = 0.11). On an individual basis, 10 athletes (Responders) improved their running economy with increased FF bending stiffness (∆O2 = −2.9%), while eight athletes (Non-Responders) worsened or did not improve their running economy in a stiff shoe (∆O2 = +1.0%). In stiff footwear, Responders experienced kinematic changes at the ankle joint (decreased angular velocity) that likely resulted in decreased energy requirement for muscular contractions due to a presumed shift on their individual force–velocity relationship. The lack of improvement in running economy by the Non-Responders may be attributed to a presumed lack of a shift in the force–velocity relationship of the calf musculature. Instead, Non-Responders experienced kinematic changes (increased ankle plantarflexion during push phase with stiff footwear) that likely hindered their moment-generating capability potentially due to a shift on their individual force–length relationship. These findings represent important progress towards explaining inter-individual changes in running economy with different footwear bending stiffness.
There is evidence that increasing the longitudinal bending stiffness of sprinting footwear can lead to improved sprinting performance although this has not yet been established. This study examined the effect of four known shoe stiffness conditions on both sprinting performance and metatarsophalangeal joint (MTPJ) motion. Twelve trained sprinters performed 40 m maximal sprints along an indoor running track, two sprints in each stiffness condition, and high-speed video (600 Hz) recorded two-dimensional MTPJ motion during ground contact. To explore individual responses to the footwear manipulations, three-dimensional (1000 Hz) kinematic and kinetic data were collected during maximal sprinting for two sprinters. At the group-level, increasing shoe bending stiffness elicited no significant differences in sprinting performance or MTPJ motion, with any changes between conditions being subject-specific. In-depth individual analyses revealed that increased shoe stiffness could restrict motion about the MTPJ and there appeared to be a preferred stiffness for best performance. This notion of individual optimal sprint shoe stiffness and what factors might contribute to the optimum requires further investigation.
Purpose:
The purpose of this study was to assess research aimed at measuring performance enhancements that affect success of individual elite athletes in competitive events.
Analysis:
Simulations show that the smallest worthwhile enhancement of performance for an athlete in an international event is 0.7-0.4 of the typical within-athlete random variation in performance between events. Using change in performance in events as the outcome measure in a crossover study, researchers could delimit such enhancements with a sample of 16-65 athletes, or with 65-260 in a fully controlled study. Sample size for a study using a valid laboratory or field test is proportional to the square of the within-athlete variation in performance in the test relative to the event; estimates of these variations are therefore crucial and should be determined by repeated-measures analysis of data from reliability studies for the test and event. Enhancements in test and event may differ when factors that affect performance differ between test and event; overall effects of these factors can be determined with a validity study that combines reliability data for test and event. A test should be used only if it is valid, more reliable than the event, allows estimation of performance enhancement in the event, and if the subjects replicate their usual training and dietary practices for the study; otherwise the event itself provides the only dependable estimate of performance enhancement. Publication of enhancement as a percent change with confidence limits along with an analysis for individual differences will make the study more applicable to athletes. Outcomes can be generalized only to athletes with abilities and practices represented in the study.
Conclusion:
estimates of enhancement of performance in laboratory or field tests in most previous studies may not apply to elite athletes in competitive events.
Updated, revised and enhanced with new features, the fifth edition of Making Sense of Sports is the strongest yet. Ellis Cashmore's unique multidisciplinary approach to the study of sports remains the only introduction to combine anthropology, biology, economics, history, philosophy, psychology, sociology with cultural and media studies to produce a distinct unbroken vision of the origins, development and current state of sports. New chapters on exercise culture and the moral climate of sports supplement an thoroughly overhauled text that includes fresh material on Islam, sports management and corruption. The new text is designed to reflect the changing culture of sports. Now packed with teaching supplements, including access to a dedicated online resource headquarters with podcasts of interviews with key scholars, self-assessment test banks, PowerPoint presentations and hyperlinks, the new edition contains a glossary of sports terms as well as guides to further reading, capsule explanations and model essays. In short, Making Sense of Sports is an all-purpose introduction to the study of sports. Readership: Its readers will be those embarking on studies in sports, leisure and popular culture, whether in the social or physical sciences or humanities.
Sprint and distance running have experienced remarkable performance improvements over the past century. Attempts to forecast running performances share an almost similarly long history but have relied so far on relatively short data series. Here, we compile a comprehensive set of season-best performances for eight Olympically contested running events. With this data set, we conduct (1) an exponential time series analysis and (2) a power-law experience curve analysis to quantify the rate of past performance improvements and to forecast future performances until the year 2100. We find that the sprint and distance running performances of women and men improve exponentially with time and converge at yearly rates of 4% ± 3% and 2% ± 2%, respectively, towards their asymptotic limits. Running performances can also be modelled with the experience curve approach, yielding learning rates of 3% ± 1% and 6% ± 2% for the women's and men's events, respectively. Long-term trends suggest that: (1) women will continue to run 10-20% slower than men, (2) 9.50 s over 100 m dash may only be broken at the end of this century and (3) several middle- and long-distance records may be broken within the next two to three decades. The prospects of witnessing a sub-2 hour marathon before 2100 remain inconclusive. Our results should be interpreted cautiously as forecasting human behaviour is intrinsically uncertain. The future season-best sprint and distance running performances will continue to scatter around the trends identified here and may yield unexpected improvements of standing world records.
The relationship between VO2 and velocity of running (running economy) has been rather casually dealt with until very recently, and there still remains considerable disagreement as to the importance of this variable. Various factors which have been shown, or appear, to affect running economy include environment (temperature, altitude, running surface), fatigue, age, weight, state of fitness, and inherent differences. That differences between individuals and within individuals can and do exist seems clear; the questions which need to be addressed in future research are: (1) What type of training is most effective in bringing about changes in running economy? and (2) How much change in economy can be expected with optimum training? Furthermore, it is suggested that running economy be investigated as an entity, so that changes that may take place with time or training can be more accurately related to their cause. (C)1985The American College of Sports Medicine