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Effects of Highly Cushioned and Resilient Racing Shoes on Running Economy at Slower Running Speeds
Abstract
Purpose:
The Nike Vaporfly line of running shoes improves running economy by ∼2.7% to 4.2% at running speeds of 13 to 18 km·h-1. It is unclear whether similar benefits are conferred at slower speeds. Our purpose was to determine the effects of the Nike ZoomX Vaporfly Next% 2 (VFN2) on running economy at 10 and 12 km·h-1 compared with a mass-matched control (CTRL) shoe.
Methods:
Sixteen runners completed 4 × 5-minute trials at both 10 and 12 km·h-1 on the same day. Each shoe was tested twice at each speed in a counterbalanced, mirrored sequence. Data are displayed as mean (SD).
Results:
A 2-way repeated-measures analysis of variance showed a significant shoe × speed interaction for oxygen consumption (P = .021). At 12 km·h-1, oxygen consumption (in mL·kg-1·min-1) was lower (-1.4% [1.1%]; P < .001) for VFN2 (35.8 [1.7]) relative to CTRL (36.4 [1.7]). That was greater in magnitude than the differences observed at 10 km·h-1 (-0.9% [1.8%]; P = .065) between VFN2 (29.4 [1.9]) and CTRL (29.6 [1.9]).
Conclusions:
From these data, it appears that the VFN2 still enhances running economy at 10 and 12 km·h-1; however, these benefits are smaller in magnitude compared with previous research at faster speeds.
... Several laboratory experiments examining AFT models from either Nike, Adidas, or Saucony in recreational runners at slower running speeds of 9-15 km/h reported similar RE benefits of 1.6-5.0%, indicating that runners can benefit from AFT independent of running speed [25][26][27][28][29]. Notably, when comparing the same AFT model at different running speeds, RE benefits appear to increase with greater running speed [28][29][30]. As kinetic energy is partially stored in and returned from the midsole foam, and because the optimal midsole LBS has been shown to depend on running speed [20,30], an association between running speed and RE benefit may be expected. ...
... indicating that runners can benefit from AFT independent of running speed [25][26][27][28][29]. Notably, when comparing the same AFT model at different running speeds, RE benefits appear to increase with greater running speed [28][29][30]. As kinetic energy is partially stored in and returned from the midsole foam, and because the optimal midsole LBS has been shown to depend on running speed [20,30], an association between running speed and RE benefit may be expected. Interestingly, this relationship appears to be present in both elite-level and amateur runners, with amateurs benefitting to a greater extent from AFT models [28]. ...
... It is conceivable that some AFT shoes, for example, might simply be better suited for recreational athletes running at slower speeds. Further, Joubert et al. [30] focused on average group-level RE improvements, which neglects inter-individual variability and should thus not be misinterpreted that every runner could expect to gain this amount of RE benefit. A different approach recently proposed by Heyde et al. [32] addresses these issues by reporting the percentage of runners likely to receive a given amount of RE improvement. ...
Carbon plate running shoes (CPRSs) have gained widespread popularity among elite and amateur runners, representing one of the most substantial changes in running gear over the past decade. Compared to elite runners, however, amateurs run at lower speeds and show more diverse running styles. This is a meaningful difference as many previous studies on CPRSs focus either on highly trained male runners and higher speeds or only on a single CPRSs manufacturer. The present study aims at bridging this gap by investigating how CPRSs from four different manufacturers affect running economy in amateurs of both sexes at their individual running speeds. For this purpose, 21 trained amateur triathletes (12 men; 9 women) completed an incremental treadmill test until volitional exhaustion, yielding running speeds at ventilatory thresholds 1 (vVT1) and 2 (vVT2). In a second session, subjects ran five trials of 3 × 3 min (speeds of 90% vVT1, ½ (vVT1 + vVT2), and 100% vVT2), wearing one out of four different pairs of CPRSs or their own preferred non-CPRS shoes in each trial. Our results show that tested CPRS models resulted in a significant reduction in the mean energy cost of transport, compared to the non-CPRS control condition, with Cohen’s d amounting to −1.52 (p = 0.016), 2.31 (p < 0.001), 2.57 (p < 0.001), and 2.80 (p < 0.001), respectively, although effect sizes varied substantially between subjects and running speeds. In conclusion, this study provides evidence that amateur athletes may benefit from various manufacturers’ CPRS models at their typical running speeds to a similar degree as highly trained runners. It is recommended that amateur athletes evaluate a range of CPRSs and select the shoe that elicits the least subjective sensation of fatigue over a testing distance of at least 400–1000 m.
... 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. ...
... To our knowledge, this is the first study to directly examine the influence of shoe type on the relationship between W MET and Stryd footpod metrics. As intended, the HPRS significantly improved running economy by lowering W MET 5-6% compared to CTS, which was 1-2% more than previous studies have shown (Hunter et al., 2019;Joubert et al., 2023;Dustin P. Joubert & Jones, 2022). However, Stryd RP was not significantly affected by shoe type. ...
... This interaction was not observed for relative measures (p = 0.079). However, since RP and speed are very strongly related (Garcia-Pinillos et al., 2018;García-Pinillos et al., 2019), the interaction effect for absolute measures is also supported by a separate investigation (Joubert et al., 2023) which demonstrated an interaction between shoe type and speed using a similar HPRS (Nike Vaporfly Next% 2). ...
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.
... 5 Multiple studies since have independently confirmed that AFT, implemented now by a variety of shoe manufacturers, can significantly improve RE compared with traditional racing shoes. [6][7][8][9] Improvements in RE allow athletes to run faster at a given physiological intensity 10,11 and likely explain much of the performance time improvements observed in competitive road racing and in controlled experiments. 12,13 More recently, between 2020 and 2021, Nike released a new track spike, the Dragonfly, that implemented similar AFT features (ie, soft, resilient foam with an embedded, fiberglass plate) to those previously described in road racing shoes. ...
... This included 3 AFT racing shoes (Nike Vaporfly Next% 2-VF2; Nike Alphafly Next%-AF; Adidas Adios Pro 2-AP2); 1 control shoe (Asics Hyperspeed-CTRL shoe ); 2 AFT track spikes (Nike Dragonfly-DF; Adidas Avanti TYO-AV); and 1 control spike (Nike Rival-CTRL spike ). Some of the shoes used in the study had been used in previous studies in our laboratory 8,9 ; however, no shoe had >34 km accumulated on it at the start of the present study, and none had >40 km by the conclusion of the study. Although we were able to purchase some of the shoe lineup in women's sizes, the AV and CTRL spike were not available, so, unfortunately, the study was limited to male subjects. ...
... Looking at their best AFT shoe to the DF spike, 1 female participant showed a ∼1.1% RE benefit in the AF shoe and 1 a ∼0.3% benefit in the DF spike. Previous studies have shown similar RE benefits in male and female subjects in investigations of AFT on RE. 6,9 Thus, although we were unable to include a full sample of female participants in the current study, we suspect these findings would also apply to female runners. ...
Purpose:
Determine the effects of advanced footwear technology (AFT) in track spikes and road-racing shoes on running economy (RE).
Methods:
Four racing shoes (3 AFT and 1 control) and 3 track spikes (2 AFT and 1 control) were tested in 9 male distance runners on 2 visits. Shoes were tested in a random sequence over 5-minute trials on visit 1 (7 trials at 16 km·h-1; 5-min rest between trials) and in the reverse/mirrored order on visit 2. Metabolic data were collected and averaged across visits.
Results:
There were significant differences across footwear conditions for oxygen consumption (F = 13.046; P < .001) and energy expenditure (F = 14.710; P < .001). Oxygen consumption (in milliliters per kilogram per minute) in both the first AFT spike (49.1 [1.7]; P < .001; dz = 2.1) and the other AFT spike (49.3 [1.7]; P < .001; dz = 1.7) was significantly lower than the control spike (50.2 [1.6]), which represented a 2.1% (1.0%) and 1.8% (1.0%) improvement in RE, respectively, for the AFT spikes. When comparing the subjects' most economic shoe by oxygen consumption (49.0 [1.5]) against their most economic spike (49.0 [1.8]), there were no statistical differences (P = .82). Similar statistical conclusions were made when comparing energy expenditure (in watts per kilogram).
Conclusions:
AFT track spikes improved RE ∼2% relative to a traditional spike. Despite their heavier mass, AFT shoes resulted in similar RE as AFT spikes. This could make the AFT shoe an attractive option for longer track races, particularly in National Collegiate Athletic Association and high school athletics, where there are no stack-height rules.
... With AFT consisting of a combination of multiple characteristics that work together to influence metabolic efficiency, researchers have yet to be able to fully explain the source(s) of these metabolic benefits. When tested at speeds between 13 and 18 km•h -1 , VP have been shown to improve ME by 2.7 to 4.2% on average (Joubert et al., 2023), with lesser metabolic benefits achieved at slower running speeds and different brands' AFT models providing varying metabolic benefits (~0.1 to 3.0%) (Joubert & Jones, 2022). Recent meta-analyses, commentaries, and review articles have synthesized the current literature's understanding of individual contributions of different AFT characteristics towards the total ME improvements measured in runners (Kram, 2022;Nigg et al., 2020;Ortega et al., 2021;Rodrigo-Carranza et al., 2022b). ...
... Running velocity seems to have an influence on metabolic benefits incurred from AFT, with (Joubert et al., 2023) seeing an interaction between speed and VP RE benefits at 10 and 12 km•h -1 , with 1.4% and 0.9% RE benefits in VP at each respective speed. ...
... Furthermore, these RE benefits with VP use at these slower speeds tested by Joubert et al. (2023) are lesser than those reported with faster testing speeds (Barnes & Kilding, 2019;Hébert-Losier, Finlayson, Driller, et al., 2022;Hoogkamer et al., 2018;Hunter et al., 2019;Joubert & Jones, 2022;Knopp et al., 2023). This influence of velocity on ME benefits from AFT was demonstrated by a meta-analysis conducted by Knopp et al. (2023) that showed effect sizes of EC and RE benefits from AFT scaled with increasing testing speeds. ...
“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.
... 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. 14 It would thus be beneficial to inform this standard of recreational runner of the potential value of super shoes before adopting their use in training and competition. ...
... 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. Although not all subjects responded equally well, as in previous research, 11,13,16 each one experienced a reduction in energy cost in the super shoes. As previous research on another brand of super shoe found that gains at 10 and 12 km·h −1 were much lower than at 16 km·h −1 , 13 it is possible that some shoes are more suited to providing an energy cost benefit at slow speeds, and others at faster speeds. ...
... This was not surprising given the previous links made between shorter contact times and running economy 27 because longer contact times have been found to occur when distance runners fatigue. 28 The subjects in this study ran for 5 minutes at each speed in each shoe, similar in duration to other previous research on super shoes 9,11,13 ; and therefore, there was no discernible fatigue that occurred. Indeed, the only change that occurred between the first and fifth minutes of testing was a small mean decrease of 0.004 seconds in flight time, which showed that any effects of the super shoes occurred as early as 1 minute after commencing running. ...
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.
... The majority of early research on AFT was conducted on high level runners (Barnes & Kilding, 2019;Hoogkamer et al., 2018Hoogkamer et al., , 2019Hunter et al., 2019;Joubert et al., 2023). ...
... Then at 17 km/h they were more economical in a shoe with increased LBS. Furthermore, when comparing the Nike Vaporfly against a mass-matched control shoe Joubert et al. (2023) found the performance benefits to be reduced at slower speeds. ...
... Therefore, the metabolic benefits associated with "supershoes" must also be prevalent in females, but there is currently little supporting evidence. Indeed, two studies assessing the metabolic effects of "super-shoes" have included a combination of male and female runners (7,28), but the interaction of strike pattern and shoes on energetic costs of running explicitly in female runners remains unknown. ...
... For example, others have observed average RE improvements ranging between 3.97% and 4.80% at testing speeds between 14 and 20 km·h -1 in men and women (6,7,23). This may be partially due to the testing speed of this study (12.9 km·h -1 ) which is slower than reported testing speeds of previous studies (6,7,23,28). This supports recent findings that metabolic improvements of "super-shoes" are smaller (e.g., 1.4% and 0.9% benefit at 12 and 10 km·h -1 , respectively) at slower speeds in both men and women (8). ...
Super-shoes” are designed to improve endurance running performance by reducing the metabolic demands of running. While the research on “super-shoes” is still developing and has mostly been studied in male runners, it is not clear how possible mediating factors, such as foot strike pattern, influence the metabolic cost and joint mechanics in competitive female runners.
Purpose
To assess the influence of “super-shoes” on metabolic cost and joint mechanics in competitive female runners, and to understand how foot strike pattern may influence the footwear effects.
Methods
Eighteen competitive female runners ran four 5-minute bouts on a force instrumented treadmill at 12.9 km·h ⁻¹ in: 1) Nike Vaporfly Next% 2 TM (SUPER) and 2) Nike Pegasus 38 TM (CON) in a randomized and mirrored order.
Results
Metabolic power was improved by 4.2% (p < 0.001; d = 0.43) and MTP negative work (p < 0.001; d = 1.22), ankle negative work (p = 0.001; d = 0.67), and ankle positive work (p < 0.001; d = 0.97) were all smaller when running in SUPER compared to CON. There was no correlation between foot strike pattern and the between-shoe (CON to SUPER) percent change for metabolic power (r = 0.093, p = 0.715).
Conclusions
Metabolic power improved by 4.2% in “super-shoes” (but only by ~3.2% if controlling for shoe mass differences) in this cohort of competitive female runners which is a smaller improvement than previously observed in men. The reduced mechanical demand at the MTP and ankle in “super-shoes” are consistent with previous literature and may explain or contribute to the metabolic improvements observed in “super-shoes”, however foot strike pattern was not a moderating factor for the metabolic improvements of “super-shoes”. Future studies should directly compare the metabolic response among different types of “super-shoes” between men and women.
... It is well known that not all runners respond biomechanically in the same way to an increase in LBS, particularly with differences in metatarsophalangeal and ankle joints kinematics (13,14,23), possibly related to biomechanical and anthropometric characteristics (2), or plantar-flexor muscle strength (13) while running at submaximal intensities. This suggests that the effect of LBS on RE could be specific to the level and speed of the runner (19,24). ...
... increase in step length of ~2 cm in national runners and an increase of ~1 cm in trained runner along with a proportional decrease in step frequency. Previous studies also reported a similar increasing step length (3,4,42) and step frequency decrease (41,42) in shoes with increased LBS compared to traditional shoes in national runners and trained runners (24). Our results show that trained runners, as opposed to national runners, increased contact time 0,1 s during running in shoes with increased LBS. ...
Introduction/purpose:
Previous results about longitudinal bending stiffness (LBS) and running economy (RE) show high variability. This study aimed to assess the effects of shoes with increased LBS on RE and performance in trained and national runners.
Methods:
Twenty-eight male runners were divided into two groups according to their 10-km performance times (trained: 38-45 min and national runners: <34 min). Subjects ran 2 x 3 min (at 9 and 13 km‧hr-1 for trained, and 13 and 17 km‧hr-1 for national runners) with an experimental shoe with carbon fiber plate to increase the LBS (Increased LBS) and a control shoe (without carbon fiber plate). We measured energy cost of running (W/kg) and spatiotemporal parameters in visit one and participants performed a 3,000 m time trial (TT) in two successive visits.
Results:
Increased LBS improved RE in the trained group at slow (11.41 ± 0.93 vs 11.86 ± 0.93 W·kg-1) and fast velocity (15.89 ± 1.24 vs 16.39 ± 1.24 W·kg-1) and only at the fast velocity in the national group (20.35 ± 1.45 vs 20.78 ± 1.18 W·kg-1). The improvements in RE were accompanied by different changes in biomechanical variables between groups. There was a similar improvement in the 3,000 m TT test in Increased LBS for trained (639 ± 59 vs 644 ± 61 s in control shoes) and national runners (569 ± 21 vs 574 ± 21 s in control shoes) with more constant pace in increased LBS compared to control shoes in both groups.
Conclusions:
Increasing shoe LBS improved RE at slow and fast velocities in trained and only at fast velocity in national runners. However, the 3,000 m TT test improved similarly in both levels of runners with increased LBS. The improvements in RE are accompanied by small modifications in running kinematics that could explain the difference between the different levels of runners.
... Hata et al., 2022) and proportional step length increases (1.2-1.4%) (Hunter et al., 2019;Barnes & Kilding, 2019;Hata et al., 2022) in AFT road shoes compared to traditional running shoes during treadmill running at constant speeds (Hunter et al., 2019;Barnes & Kilding, 2019;Hata et al., 2022;Joubert, Dominy & Burns, 2023), during track running in AFT road shoes (1.3-2.7%) (Hébert-Losier et al., 2024) and recently in AFT spikes (1.9-2.3%) . ...
... 1,3,4 In addition, we also showed that the benefits of AFT NVF were similar between men and women at slower speeds. 45 ...
The modern era of running shoes began in the 1960s with the introduction of simple polymer midsole foams, and it ended in the late 2010s with the introduction of advanced footwear technology (AFT). AFT is characterized by highly compliant, resilient, and lightweight foams with embedded, rigid, longitudinal architecture. This footwear complex improves a runner’s efficiency, and it introduced a step change in running performance. Purpose : This review serves to examine the current state of knowledge around AFT—what it is and what we know about its ingredients, what benefits it confers to runners, and what may or may not mediate that benefit. We also discuss the emerging science around AFT being introduced to track-racing spikes and how it is currently regulated in sporting contexts. Conclusions : AFT has changed running as a sport. The construction of AFT is grossly understood, but the nature of the interacting elements is not. The magnitude of the enhancement of a runner’s economy and performance has been characterized and modeled, but the nuanced factors that mediate those responses have not. With these knowns and unknowns, we conclude the review by providing a collection of best practices for footwear researchers, advice for runners interested in AFT, and a list of pertinent items for further investigation.
... A review of the existing literature unequivocally summarised that supershoes are performance enhancing [3] with several studies typically focusing on significant improvements in running economy and/or lower time trial completion times as the basis for this argument. However the specific values of these have differed from study to study, vary based on the test protocol utilised or the targeted running velocity [23] and whether the shoes are normalised for their mass or not [24]. The seminal studies and their proposed investigation of supershoe performance enhancement are summarised in Table 1. ...
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.
... Second, this study was performed in a laboratory where participants needed to speed up and slow down before and after the capture volume, which may affect biomechanics. Finally, our sample was fairly homogenous with only collegiate and elite-level runners running at a faster pace, but responses to carbon-fibre plate racing shoes may be speed-dependent (Day & Hahn, 2020;Joubert et al., 2023). ...
... Improvements in RE measured in the laboratory translate directly to race performance, although the magnitude is smaller [5][6][7]. Overall, there is clear, direct evidence to suggest that AFT improves RE in distance running [7][8][9], even though these improvements might be running speed dependent [10] and differ between individuals [7,11]. While some of these studies included world-class athletes [11], most were performed with high-caliber men. ...
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.
... Parmi les nombreux facteurs contribuant à de telles blessures, les chaussures ont fait l'objet de recherches approfondies et de débats [4,5]. Nike, en tant que l'un des principaux innovateurs en matière de chaussures de sport, propose une large gamme de chaussures de course, chacune avec des caractéristiques distinctes visant à améliorer la performance et le confort [6][7][8]. Étant donné la popularité de la marque et la diversité de ses offres, il est primordial de comprendre les effets biomécaniques des chaussures de course Nike pour les professionnels de la santé et la communauté des coureurs [9][10][11]. La biomécanique de la course, y compris les forces de réaction au sol, les taux de charge et la cinématique articulaire, peut être significativement influencée par les chaussures. ...
Background
The increasing popularity of running as a form of exercise has led to a rise in running-related injuries, prompting research into different types of footwear as a potential mitigating factor. This scoping review aims to synthesize the findings of studies that have examined the effects of Nike running shoes on biomechanics and injury risk in runners.
Methods
The review was conducted using a structured methodology to assess the impact of Nike running shoes on biomechanics and injury risk in runners. The research included major academic databases such as MEDLINE, Cochrane Central, Scopus, and PEDro, using specific keywords. Inclusion criteria targeted studies on adult runners of various levels, examining the effects of Nike shoes on aspects such as biomechanics and injuries. Studies not meeting these specific criteria were excluded.
Results
The review analyzed six studies focusing on the impact of Nike running shoes on biomechanics and injury risk in runners. Findings indicated that minimalist shoes may increase the load on the Achilles tendon and pain in the shin and calf, while dual-stiffness spike shoes may reduce loading rates and ankle eversion angles.
Conclusion
This review highlights the importance of choosing footwear that is suited to the individual characteristics of runners to minimize the risk of injury.
... Running in the VP4 has also been associated with longer flight times, lower ankle ranges of motion and lower cadences (Barnes & Kilding, 2019; that could increase knee loading. A recent paper reported lesser running economy benefits of AFT shoes at slower speeds (Joubert et al., 2023), suggesting that recreational runners may benefit less from AFT shoes than elite. On the other hand, recreational runners are used to running races in heavier traditional shoes, and transitioning to AFT shoes can reduce distal mass and benefit running economy. ...
... In a comparative study, Dustin contrasted the Nike ZoomX Vaporfly Next% 2 (VFN2) with a mass-matched control shoe, evaluating their performance at 10 km/h and 12 km/h. The study indicated that while the VFN2 improved running economy, this enhancement was less pronounced than at higher velocities of 13 km/h to 18 km/h [18]. However, there are few studies on lower limb biomechanics at different velocities and the effects of different running shoes, let alone bionic shoes. ...
The running biomechanics of running shoes have been extensively investigated. However, there is limited knowledge about the use of bionic shoes compared to neutral shoes, along with the velocities involved in their use. The aim of this study was to examine the biomechanical alterations associated with various running velocities of bionic shoes. By removing different thicknesses of the forefoot section, bionic shoes created a more natural shape—close to that of a human foot. The study included 16 heel strike runners running at 10 km/h, 12 km/h and 14 km/h in bionic shoes and neutral shoes, respectively. A two-way ANOVA and SPM1d were employed for examining kinematic and kinetic differences. Regarding the results for the shoes, increased ROM was observed for the bionic shoes for the hip (p < 0.001) and ankle joints (p < 0.001). Ankle positive work (p < 0.001) and negative work (p = 0.042) also showed significant differences. Regarding the velocity results, hip ROM (p < 0.001) increased and peak knee angular velocity (p = 0.018) increased, while knee ROM (p = 0.023) decreased. The interaction effects only existed in hip (p = 0.031) and ankle (p = 0.008) ROM. The results of this study suggested that the impact of running propulsion in the bionic shoes was minimal. However, with increased velocities, the bionic shoes demonstrated the ability to absorb more force, created a more stable training environment, and contributed to injury prevention for the hip and ankle joints.
... Improvements in RE measured in the lab translate directly to race performance, although the magnitude is smaller [5][6][7]. Overall, there is clear, direct evidence to suggest that distance running advanced footwear technology improve running economy [7][8][9], even though these improvements might be running speed dependent [10] and differ between individuals [7,11]. While some of these studies included world-class athletes [11], most were performed with high-calibre, predominantly male athletes. ...
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.
Purpose: The rise of running shoes with carbon fibre plates (CFP) has caused a disruptive shift in long-distance road running footwear by significantly enhancing athletic performance. However, these shoes are more expensive and less durable than conventional ones. This paper examines how factors associated with a hedonic model of technology acceptance influence the adoption of this equipment among amateur athletes. Design/methodology/approach: We used a sample of 252 amateur athletes to explain the intention to use CFP shoes based on three factors: perceived usefulness, hedonic motivation, and subjective norm. The relationships between variables were modelled using structural equation modelling adjusted with partial least squares (PLS-SEM). Findings: The descriptive analysis of the items related to shoe acceptance suggests a general trend towards accepting CFP shoes. The PLS-SEM analysis results indicate that while the direct impact of perceived usefulness and hedonic motivation is significant on the intention to use CFP shoes, the influence of the subjective norm is not. However, when considering all effects (direct and indirect) on the intention to use CFP shoes, the total effect of the normative variable is the most significant. We have also verified that the model has predictive capacity. Research limitations/implications: This study was conducted after World Athletics had already published new regulations on running shoes. In a context other than long-distance running, it would be interesting to conduct a similar study on a technology that could improve athletic performance before being regulated and then compare the results with those obtained after the regulations have been implemented. Practical implications: The results of this paper suggest that the proposed technology acceptance model can provide a valuable approach for evaluating the acceptance of innovative advancements in sports equipment by amateur athletes when their primary motivation for practicing a particular sport is hedonic.
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.
Purpose: The aim of this study was to examine the influence of different spikes technologies on running economy and middle- and long-distance performance in trained runners. Methods: Fourteen trained female and sixteen trained male runners participated in this study. Females performed a single visit with six 200 m trials at self-perceived 800 m race pace in three different spike conditions (Control, PEBA and PEBA+Plate) twice in a mirrored order, and three 800 m trials at 4.44 m/s in each spike condition. Males completed four visits. During the first three visits they performed six 200 m trials at self-perceived 800 m race pace in each spike condition. Subsequently, they performed a 3,000 m time trial in one of the three spike conditions. During visit four, participants completed six 4-minute running economy trials at 5 m/s, twice in each condition. Results: The main effect for spike condition was significant for speed at 800 m pace (p<0.001) in females and males, for speed during the 3,000 m time trial (p=0.013) in males and for running economy at 5 m/s, (p<0.001) in males. Conclusion: At 800 m race pace females ran faster in PEBA (2.1%) and PEBA+Plate (2.0%) compared to Control. Males ran faster in PEBA (1.2%) and PEBA+Plate (2.8%) compared to Control and in PEBA+Plate than in PEBA (1.5%). Similarly, males ran the 3,000 m time trial faster in PEBA (1.0%) and PEBA+Plate (2.4%) than in Control. Running economy at 5 m/s was better in PEBA (5.1%) and PEBA+Plate (4.0%) than in Control.
Background
Running biomechanics is considered an important determinant of running economy (RE). However, studies examining associations between running biomechanics and RE report inconsistent findings.
Objective
The aim of this systematic review was to determine associations between running biomechanics and RE and explore potential causes of inconsistency.
Methods
Three databases were searched and monitored up to April 2023. Observational studies were included if they (i) examined associations between running biomechanics and RE, or (ii) compared running biomechanics between groups differing in RE, or (iii) compared RE between groups differing in running biomechanics during level, constant-speed, and submaximal running in healthy humans (18–65 years). Risk of bias was assessed using a modified tool for observational studies and considered in the results interpretation using GRADE. Meta-analyses were performed when two or more studies reported on the same outcome. Meta-regressions were used to explore heterogeneity with speed, coefficient of variation of height, mass, and age as continuous outcomes, and standardization of running shoes, oxygen versus energetic cost, and correction for resting oxygen or energy cost as categorical outcomes.
Results
Fifty-one studies (n = 1115 participants) were included. Most spatiotemporal outcomes showed trivial and non-significant associations with RE: contact time r = − 0.02 (95% confidence interval [CI] − 0.15 to 0.12); flight time r = 0.11 (− 0.09 to 0.32); stride time r = 0.01 (− 0.8 to 0.50); duty factor r = − 0.06 (− 0.18 to 0.06); stride length r = 0.12 (− 0.15 to 0.38), and swing time r = 0.12 (− 0.13 to 0.36). A higher cadence showed a small significant association with a lower oxygen/energy cost (r = − 0.20 [− 0.35 to − 0.05]). A smaller vertical displacement and higher vertical and leg stiffness showed significant moderate associations with lower oxygen/energy cost (r = 0.35, − 0.31, − 0.28, respectively). Ankle, knee, and hip angles at initial contact, midstance or toe-off as well as their range of motion, peak vertical ground reaction force, mechanical work variables, and electromyographic activation were not significantly associated with RE, although potentially relevant trends were observed for some outcomes.
Conclusions
Running biomechanics can explain 4–12% of the between-individual variation in RE when considered in isolation, with this magnitude potentially increasing when combining different variables. Implications for athletes, coaches, wearable technology, and researchers are discussed in the review.
Protocol registration
https://doi.org/10.17605/OSF.IO/293ND (OpenScience Framework).
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.
Background:
Compared to conventional racing shoes, Nike Vaporfly 4% running shoes reduce the metabolic cost of level treadmill running by 4%. The reduction is attributed to their lightweight, highly compliant, and resilient midsole foam and a midsole-embedded curved carbon fiber plate. We investigated whether these shoes also reduce the metabolic cost of moderate uphill (+3°) and downhill (-3°) grades. We tested the null hypothesis that compared to conventional racing shoes, highly-cushioned shoes with carbon-fiber plates would impart the same ∼4% metabolic power (W/kg) savings during uphill and downhill running as they do during level running.
Methods:
After familiarization, 16 competitive male runners performed six 5-min trials (2 shoes × 3 grades) in 2 Nike marathon racing shoe models (Streak 6 and Vaporfly 4%) on a level, uphill (+3°), and downhill (-3°) treadmill at 13 km/h (3.61 m/s). We measured submaximal oxygen uptake and carbon dioxide production during Minutes 4-5 and calculated metabolic power (W/kg) for each shoe model and grade combination.
Results:
Compared to the conventional shoes (Streak 6), metabolic power in the Vaporfly 4% shoes was 3.83% (level), 2.82% (uphill), and 2.70% (downhill) less (all p < 0.001). The percent change in metabolic power for uphill running was less compared to level running (p = 0.04, effect size, ES = 0.561) but was not statistically different between downhill and level running (p = 0.17, ES = 0.356).
Conclusion:
On a running course with uphill and downhill sections, the metabolic savings and hence performance enhancement provided by Vaporfly 4% shoes would likely be slightly less overall, compared to the savings on a perfectly level race course.
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.
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.
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.
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.
We compared 10 published equations for calculating energy expenditure from oxygen consumption and carbon dioxide production using data for 10 high-caliber male distance runners over a wide range of running velocities. We found up to a 5.2% difference in calculated metabolic rate between 2 widely used equations. We urge our fellow researchers abandon out-of-date equations with published acknowledgments of errors or inappropriate biochemical/physical assumptions.
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.
Ground reaction force (GRF) data were collected on twenty adult males during running stance to establish normative standards to aid in assessment of the gait of atypical runners. Subjects ran between 30 and 40 trials across a Kistler 0.6 X 0.9 m force platform at self-selected speeds ranging from 2.5 to 5.5 m s-1. Best fit polynomials for a given descriptor variable were constructed for each subject and the polynomials were evaluated as a function of running speed. Predicted means and standard deviations (based on the polynomials) were calculated and multivariate analyses of variance were performed. The descriptor variables: impact peak, loading rate, thrust maximum, decay rate, average vertical GRF, change in vertical velocity, braking impulse, propulsive impulse and stance time were determined to be running speed dependent (p less than 0.001). Specific patterns associated with the breaking component of the antero-posterior GRF of heel-strikers included single, double and multiple peaks. Three dimensional graphic displays showed that, despite considerable group variability in medial-lateral GRF-time histories, consistency was evident in the patterns of individuals across speeds. Individual right-left asymmetries were clearly shown in these displays.
The spring-mass model, representing a runner as a point mass supported by a single linear leg spring, has been a widely used concept in studies on running and bouncing mechanics. However, the measurement of leg and vertical stiffness has previously required force platforms and high-speed kinematic measurement systems that are costly and difficult to handle in field conditions. We propose a new "sine-wave" method for measuring stiffness during running. Based on the modeling of the force-time curve by a sine function,this method allows leg and vertical stiffness to be estimated from just a few simple mechanical parameters: body mass, forward velocity, leg length, flight time, and contact time. We compared this method to force-platform-derived stiffness measurements for treadmill dynamometer and overground running conditions, at velocities ranging from 3.33 m.s-1 to maximal running velocity in both recreational and highly trained runners. Stiffness values calculated with the proposed method ranged from 0.67 % to 6.93 % less than the force platform method, and thus were judged to be acceptable. Furthermore, significant linear regressions (p < 0.01) close to the identity line were obtained between force platform and sine-wave model values of stiffness. Given the limits inherent in the use of the spring-mass model, it was concluded that this sine-wave method allows leg and stiffness estimates in running on the basis of a few mechanical parameters, and could be useful in further field measurements.
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.
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.
A mathematical model for terrestrial running is presented, based on a leg with the properties of a simple spring. Experimental force-platform evidence is reviewed justifying the formulation of the model. The governing differential equations are given in dimensionless form to make the results representative of animals of all body sizes. The dimensionless input parameters are: U, a horizontal Froude number based on forward speed and leg length; V, a vertical Froude number based on vertical landing velocity and leg length, and KLEG, a dimensionless stiffness for the leg-spring. Results show that at high forward speed, KLEG is a nearly linear function of both U and V, while the effective vertical stiffness is a quadratic function of U. For each U, V pair, the simulation shows that the vertical force at mid-step may be minimized by the choice of a particular step length. A particularly useful specification of the theory occurs when both KLEG and V are assumed fixed. When KLEG = 15 and V = 0.18, the model makes predictions of relative stride length S and initial leg angle θ0 that are in good agreement with experimental data obtained from the literature.
Study Design
Validity and reliability study.
Background
Providing feedback on running mechanics is a common intervention to decrease the risk of injury or to restore running after an injury. Commercially available devices are able to measure running dynamics, such as cadence, ground contact time (GCT), and vertical oscillation (VO), but there is limited evidence on the validity and reliability of these measures.
Objective
To determine the validity and reliability of measures of cadence, GCT, and VO with a fitness watch compared to a motion-analysis system.
Methods
Twenty runners ran in 3 conditions: (1) baseline (self-selected speed and cadence), (2) higher cadence, and (3) decreased vertical motion (minimal oscillation). Ten runners also performed an additional baseline running session to measure intrasession reliability. For each condition, the average cadence, GCT, and VO were collected from a watch and from a motion-capture system. Intraclass correlation coefficients (ICCs) were used to assess validity between devices. An analysis of variance with 2 repeated measures was used to determine the ability of the watch and motion analysis to detect change in running dynamics.
Results
The ICCs between the 2 measuring systems were 0.931, 0.963, and 0.749 for cadence, VO, and GCT, respectively (P<.01). The minimal detectable changes at the 95% confidence interval for cadence, VO, and GCT were 2.53 steps per minute, 0.45 cm, and 0.01 seconds, respectively, for the watch. There were no interaction effects, but there was a main effect for condition; both devices detected changes in running dynamics.
Conclusion
The watch is a valid and reliable tool for detecting changes in cadence, VO, and GCT. J Orthop Sports Phys Ther 2016;46(6):471–476. Epub 26 Apr 2016. doi:10.2519/jospt.2016.6391
A mathematical model for terrestrial running is presented, based on a leg with the properties of a simple spring. Experimental force-platform evidence is reviewed justifying the formulation of the model. The governing differential equations are given in dimensionless form to make the results representative of animals of all body sizes. The dimensionless input parameters are: U, a horizontal Froude number based on forward speed and leg length; V, a vertical Froude number based on vertical landing velocity and leg length, and KLEG, a dimensionless stiffness for the leg-spring. Results show that at high forward speed, KLEG is a nearly linear function of both U and V, while the effective vertical stiffness is a quadratic function of U. For each U, V pair, the simulation shows that the vertical force at mid-step may be minimized by the choice of a particular step length. A particularly useful specification of the theory occurs when both KLEG and V are assumed fixed. When KLEG = 15 and V = 0.18, the model makes predictions of relative stride length S and initial leg angle theta o that are in good agreement with experimental data obtained from the literature.
In this study the variation in ground reaction force parameters was investigated with respect to adaptations to speed and mode of progression, and to type of foot-strike. Twelve healthy male subjects were studied during walking (1.0–3.0 m s⁻¹) and running (1.5–6.0 m s⁻¹). The subjects were selected with respect to foot-strike pattern during running. Six subjects were classified as rearfoot strikers and six as forefoot strikers. Constant speeds were accomplished by pacer lights beside an indoor straightway and controlled by means of a photo-electronic device. The vertical, anteroposterior and mediolateral force components were recorded with a force platform. Computer software was used to calculate durations, amplitudes and impulses of the reaction forces. The amplitudes were normalized with respect to body weight (b.w.). Increased speed was accompanied by shorter force periods and larger peak forces. The peak amplitude of the vertical reaction force in walking and running increased with speed from approximately 1.0 to 1.5 b.w. and 2.0 to 2.9 b.w. respectively. The anteroposterior peak force and mediolateral peak-to-peak force increased about 2 times with speed in walking and about 2–4 times in running (the absolute values were on average about 10 times smaller than the vertical). The transition from walking to running resulted in a shorter support phase duration and a change in the shape of the vertical reaction force curve. The vertical peak force increased whereas the vertical impulse and the anteroposterior impulses and peak forces decreased. In running the vertical force showed an impact peak at touch-down among the rearfoot strikers but generally not among the forefoot strikers. The first mediolateral force peak was laterally directed (as in walking) for the rearfoot strikers but medially for the forefoot strikers.
Various features of the design of running shoes have been known to affect the performance and safety of athletes. The performance related effects of shoe design on traction and on the economy of locomotion are reviewed in this paper. Traction measurements in various types of running shoes and on various surfaces appear adequate for all but running on wet asphalt roads. Future designs should improve traction for those conditions. Effects on the economy of locomotion as small as 1% can be determined using conventional oxygen uptake measurements. The effect of carrying extra weight on the foot during running has been measured at 1% per 100 g per foot. The cost of carrying similar weights is much lower for walking or for running when the weight is carried nearer the body's centre of mass. Cushioning and other features of shoe design besides weight have been shown to have significant effects on the economy of locomotion. Optimum designs for maximising running performance should provide sufficient traction, minimal weight and maximum cushioning.
Efforts to understand human physiology through the study of champion athletes and record performances have been ongoing for about a century. For endurance sports three main factors--maximal oxygen consumption (.VO(2,max)), the so-called 'lactate threshold' and efficiency (i.e. the oxygen cost to generate a given running speed or cycling power output)--appear to play key roles in endurance performance. and lactate threshold interact to determine the 'performance .VO(2)' which is the oxygen consumption that can be sustained for a given period of time. Efficiency interacts with the performance .VO(2) to establish the speed or power that can be generated at this oxygen consumption. This review focuses on what is currently known about how these factors interact, their utility as predictors of elite performance, and areas where there is relatively less information to guide current thinking. In this context, definitive ideas about the physiological determinants of running and cycling efficiency is relatively lacking in comparison with .VO(2,max) and the lactate threshold, and there is surprisingly limited and clear information about the genetic factors that might pre-dispose for elite performance. It should also be cautioned that complex motivational and sociological factors also play important roles in who does or does not become a champion and these factors go far beyond simple physiological explanations. Therefore, the performance of elite athletes is likely to defy the types of easy explanations sought by scientific reductionism and remain an important puzzle for those interested in physiological integration well into the future.
Effect of treadmill surface stiffness on the running economy benefits of a highly-cushioned racing shoe: a pilot study
- Z A Thornton
- D P Joubert
- Thornton ZA
Table of nonprotein respiratory quotient: an update
- F Péronnet
- D Massicotte
- Péronnet F
Highly cushioned shoes improve running performance in both the absence and presence of muscle damage
- M I Black
- S H Kranen
- S Kadach
- Black MI
Shock absorbing sole layer
- Derderian T
Nike says its $250 running shoes will make you run much faster. What if that’s actually true?
- K Quealy
- J Katz
- Quealy K