Nike Vaporfly Research Articles

A methodological proof-of-concept of the teeter-totter effect

ABSTRACT The Nike Vaporfly 4% (VP4) shoe is popular due to its unique design and reported performance benefits. However, the underlying mechanisms responsible for the improvements remain unclear. One proposed mechanism is the teeter-totter effect. This study aimed to 1) experimentally test the teeter-totter theory by estimating the teeter-totter moment (MTT) in the VP4 compared to a flat shoe (CONTROL) and 2) quantify the change in the anterior-posterior position of the centre of pressure (Δxa-p) in the VP4 compared to the CONTROL. Plantar pressures and high-speed video were recorded from 15 runners in two shoe conditions. The VP4 generated a larger propulsion moment, MP, ( ∫ M P dt = 90.46 ± 38.87 Nms; p < 0.001, d = 1.95), suggesting the presence of an MTT in the VP4 ( ∫ M TT dt = 57.16 ± 24.35 Nms) when compared to the CONTROL ( ∫ M P dt = 33.30 ± 14.52 Nms). Δxa-p was greater in the VP4 (Δxa-p = 9.48 ± 6.08 mm; p < 0.001, d = 2.07) compared to the CONTROL (Δxa-p = 0.54 ± 0.67 mm). This study provides a methodological proof-of-concept for the teeter-totter theory. The findings highlight the possibility of a teeter-totter effect resulting in greater heel propulsion while running in an AFT shoe construction, assuming a constant muscle moment and pivot point.

The Influence of "Super-Shoes" and Foot Strike Pattern on Metabolic Cost and Joint Mechanics in Competitive Female Runners.

The objective of this study is 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. Eighteen competitive female runners ran four 5-min bouts on a force instrumented treadmill at 12.9 km·h -1 in 1) Nike Vaporfly Next% 2™ (SUPER) and 2) Nike Pegasus 38™ (CON) in a randomized and mirrored order. Metabolic power was improved by 4.2% ( P < 0.001; d = 0.43) and metatarsophalangeal (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 with CON. There was no correlation between foot strike pattern and the between-shoe (CON to SUPER) percentage change for metabolic power ( r = 0.093, P = 0.715). 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.

Biomechanics and subjective measures of recreational male runners in three shoes running outdoors: a randomised crossover study

We compared biomechanical and subjective data from outdoor running in: habitual (OWN), Saucony Endorphin Racer 2 minimal (FLAT) and Nike Vaporfly 4% (VP4) shoes. We also explored relationships between comfort measures and the collected data. Eighteen male recreational runners ran three 1.5-km trials outdoors, once per shoe. The first 1.1 km was run at a self-selected comfortable (slower) speed, and last 400 m at perceived 5-km race pace (faster). A GPS-enabled smartwatch, 15-m Optojump system, high-speed camera and tibial accelerometer collected biomechanical data. Subjective data on comfort, shoe properties and overall running experience were collected using visual analogue scales (VAS) and rankings. Cadence, leg stiffness and vertical stiffness were greater in FLAT than both OWN and VP4 at the slower speed (trivial to small ES). At both speeds, footstrike angles were smaller in FLAT (small to large ES), while propulsion phase was shorter in VP4 (moderate to large ES). FLAT was ranked as the least comfortable at the slower speed and most likely to cause injury, whereas OWN as the most comfortable and least likely to cause injury. Comfort was not significantly different at the faster speed between shoes. Comfort measures were more strongly correlated to subjective than biomechanical data. The two experimental shoes generally had non-significant or small effects on running biomechanics versus OWN. As VP4 are more like traditional than minimal shoes, these were perceived as more comfortable. Running speed appeared to affect subjective measures. Speed should be considered when prescribing and selecting shoes.

Does deconstructing the Nike Vaporfly 4% affect running mechanics?

Does deconstructing the Nike Vaporfly 4% affect running mechanics?

Why disruptive sport competition technologies are used by amateur athletes? An analysis of Nike Vaporfly shoes

Objectives: The Vaporfly tech by Nike (VFT) for road running shoes has supposed a disruption in distance running shoes. Academic research suggests that VFT improves performance, at least, in elite and sub-elite athletes. This paper assesses empirically factors influencing the acceptance of disruptive competition technologies, focusing on the perceptions about the VFT shoes by amateur athletes.&#x0D; Material and methods: We analyse a survey over 252 Spanish amateur athletes. Our research uses Unified Theory of Acceptance and Use of Technology (UTAUT), including ethical awareness of athlete that is measured by means of their judgement on moral equity (ME), and athlete income.&#x0D; Results: The proposed model explains almost half of the intention to use (IU) disruptive technologies by athletes in all regressions. Significant influential factors on IU are Easiness to Use (EU), Performance Expectancy (PE), perception on ME and Income level of the athlete. Surprisingly, Social Influence (SI) has a weak influence on the IU. Structural equation model fitted by means of partial least squares leads to similar results than Poisson regression.&#x0D; Discussion: This paper applies a theoretical framework that combines findings in consumer behaviour (UTAUT model) and moral equity dimension of a multiple ethical scale to explain intention to use VFT. Of course, proposed methodology can be used to evaluate a disruptive tech within the context of any other sport.&#x0D; Conclusions: These findings have important implications in the sport industry. As we expected and also has shown by reviewed literature linked to sport tech, conventional UTAUT has been revealed useful theoretical framework to explain the acceptance of disruptive sport competitive techs. But, in addition, ethical aspects also should be considered in their development.

Effects of Highly Cushioned and Resilient Racing Shoes on Running Economy at Slower Running Speeds.

The Nike Vaporfly line of running shoes improves running economy by ∼2.7% to 4.2% at running speeds of 13 to 18km·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 12km·h-1 compared with a mass-matched control (CTRL) shoe. Sixteen runners completed 4 × 5-minute trials at both 10 and 12km·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). A 2-way repeated-measures analysis of variance showed a significant shoe × speed interaction for oxygen consumption (P = .021). At 12km·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 10km·h-1 (-0.9% [1.8%]; P = .065) between VFN2 (29.4 [1.9]) and CTRL (29.6 [1.9]). From these data, it appears that the VFN2 still enhances running economy at 10 and 12km·h-1; however, these benefits are smaller in magnitude compared with previous research at faster speeds.

A Comparison Of Running Economy Across Seven Carbon-Plated Racing Shoes

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 a carbon-fiber plate and thicker, new midsole foams. However, none of these new shoes have been compared to the Vaporfly. PURPOSE: Compare the effects of 7 different carbon-plated shoes and 1 traditional racing shoe on running economy. METHODS: Seven carbon-plated shoes: Hoka Rocket X (Hoka RX), Saucony Endorphin Pro (Saucony EP), Nike Alphafly (Nike AF), Asics Metaspeed Sky (Asics MS), Nike Vaporfly 2 (Nike VF2), New Balance RC Elite (New Bal RC), Brooks Hyperion Elite 2 (Brooks HE2), and 1 traditional shoe: Asics Hyperspeed (Asics HS) were tested in 12 male runners (5 k best: 16.0 ± 0.7 min) on two visits. Shoes were tested in a random sequence over 8 x 5-minute trials (16 km‧hr-1; 5-minute 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. A repeated-measures ANOVA was used to compare dependent variables across shoe conditions along with follow-up pairwise comparisons. RESULTS: VO2 (ml‧kg-1‧min-1; % change from Asics HS) was significantly different across shoes. Hoka RX (51.67 ± 2.07; -0.08 ± 1.04%) and Brooks HE2 (51.42 ± 1.72; -0.53 ± 0.90%) 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%). In terms of running mechanics, statistically significant differences were limited. However, cadence (steps‧min-1) was significantly lower in the Nike AF (174.6 ± 10.4) than the Asics HS (176.5 ± 10.3). CONCLUSION: Only the Nike AF and Asics MS matched the previously established Nike VF2 in running economy improvements. From these data, it appears the advantages conferred by new running shoe advancements are not fully shared across the competitive running shoe market.

Kinematics of recreational male runners in “super”, minimalist and habitual shoes

ABSTRACT 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, O2peak: 55.2 ± 4.3 ml · kg−1·min−1) attended 3 sessions after completing an O2peak test in which sagittal plane 3D kinematics at submaximal running speeds (60%, 70% and 80% ʋ 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 shorter 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.

The Nike Vaporfly 4%: a game changer to improve performance without biomechanical explanation yet

In a recent article published in Footwear Science, the teeter-totter effect was indirectly observed with the Nike Vaporfly 4% (VP4) running shoe. This mechanism was attributed to the presence of a curved carbon-fibre (stiff) plate, and potentially causes runners to propel forward during push-off. It was suggested that such mechanism should explain the 4% improvement of performance of the VP4 compared to regular shoes. However, there was, to the best of the authors’ knowledge, no attempt to associate this VP4-specific mechanism to the change in running economy and personal best time yet. Furthermore, a recent article published in the Journal of Sport and Health Science observed that the stiffening effect of the curved carbon-fibre plate plays a limited role in the energy savings, which therefore questions the presence of the teeter-totter effect in the VP4 shoe. In our view, the better running economy and personal best time obtained with the VP4 shoe cannot be currently explained from a biomechanical standpoint. With this letter, we would like to (1) summarise the specificities of the VP4 shoe, (2) report the observed improvements in running economy and personal best time, and (3) point out the absence of any biomechanical explanation to the better performance yet.

Carbon Plate Shoes Improve Metabolic Power and Performance in Recreational Runners.

This study compared metabolic power (MP) and time trial (TT) running performance between Adidas Adizero Adios (AAA) and Nike VaporFly 4% (NVP). Thirty-seven runners completed three laboratory sessions and two field sessions (n=30). After familiarization (visit 1), participants completed eight 6-min treadmill running bouts (four with each shoe, counterbalanced) at their preferred pace, and MP was assessed using indirect calorimetry (visits 2 and 3). During visits 4 and 5, participants completed two outdoor TTs (~3.5 km) in NVP and AAA (counterbalanced). Compared with AAA, NVP exhibited superior MP (NVP: median=13.88 (Q1-Q3=12.90-15.08 W/kg; AAA: median=14.08 (Q1-Q3=13.12-15.44 W/kg; z=-4.81, p<.001, effect size=.56) and TT (NVP=793±98 s; AAA=802±100 s, p=.001; effect size=.09). However, there was no relationship between changes in MP and changes in TT between shoes (r=.151 p=.425, 95% confidence interval=[-.22; .48]). Our results demonstrate that NVP, compared with AAA, improves MP and TT in recreational runners. The lack of correlation between changes in MP and TT indicates that factors other than improved MP contribute to faster short-distance TT with NVP.

A comparison of running economy across seven highly cushioned racing shoes with carbon-fibre plates

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.

Influence of advanced shoe technology on the top 100 annual performances in men\u2019s marathon from 2015 to 2019

The NIKE Vaporfly shoe was introduced in May 2017 as part of the original #Breaking2 Project (an event aimed to run the first marathon under 2 h). This new advanced shoe technology (NAST) changed the footwear design conception. The aim of this study was (i) to analyse the effect of NAST in men’s marathon performance, (ii) to analyse whether the changes in the environmental constraints (temperature and wind) and orography of the marathons, age and birthplace of the runners has changed from 2015 to 2019 and (iii) to analyse the impact of NAST on the historical 50 best performances. Data from top-100 men's marathon performances were collected in that timeframe. The shoes used by the athletes were identified (in 91.8% of the cases) by publicly available photographs. External and environmental conditions of each marathon and age and birthplace of the runners were also analysed. Marathon performances improved from 2017 onwards between 0.75 and 1.50% compared to 2015 and 2016 (p < 0.05). In addition, the improvement was greater in the upper deciles than in the lower ones (p < 0.001). Runners wearing NAST ran ~ 1% faster in marathon compared to runners that did not use it (p < 0.001). When conducting an individual analysis of athletes who ran with and without NAST, 72.5% of the athletes who completed a marathon wearing NAST improved their performance by 0.68% (p < 0.01). External and environmental conditions, age or birthplace of runners seems not to have influenced this performance improvement. NAST has had a clear impact on marathon performance unchanged in the environmental constraints (temperature and wind), orography, age, and birthplace of the runners but with differences between venues.

Metabolic cost of level, uphill, and downhill running in highly cushioned shoes with carbon-fiber plates

BackgroundCompared 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 could 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. MethodsAfter 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. ResultsCompared to the conventional shoes (Streak 6), the 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 of 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). ConclusionOn 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.

Technology triumphs in track and synthetic skin reveals robot boo-boos

New tech for the Olympics When some Olympic athletes benefit from developments in materials science, it can kick up a heap of controversy, as it leads some to question if this gives an advantage to athletes who have enough money or sponsors to afford the new technology. Think Australian sprinter Cathy Freeman in 2000 wearing her air-parting polyurethane-coated hooded bodysuit, US swimmer Michael Phelps and others in 2008 who wore go-faster polyurethane shark skin–patterned swimsuits and collected 98% of the indoor swimming medals, and all three male marathon medalists in 2016 who wore Nike Vaporfly 4% road-running shoes featuring a carbon-fiber plated sole that cut the metabolic energy they expended by 4%. This summer’s Tokyo Olympics promises to be no different. This Newscriptster’s hunch is that the latest tech leap will involve novel designs and materials for track shoes with spikes on the bottom. Until now spikes were designed to

The Effects Of The Nike Vapor Fly 4% Shoes On Running Economy In Fatigued Female Runners

The Nike Vaporfly 4% shoe (VP) has been shown to improve running economy (RE) up to 4% in subelite male runners. Whether these improvements extend to other subject groups, such as female runners or fatigued runners, remains unknown. PURPOSE: The purpose of this study was to determine if trained female runners gain the same 4% improvement in RE as males and if the improvement is observed post-fatigue. METHODS: Nine well-trained collegiate female runners completed one session alternating between the VP and the control shoe, Nike Streaks (NS). Subjects performed three vertical jumps in each shoe on a force pad to determine jump height and estimate stored energy return from each shoe. Subjects then performed two, 5-min treadmill running trials at 6.7 mph using a metabolic cart to measure oxygen consumption. Mean oxygen uptake over the last two minutes of each trial was used to determine RE. Following the first jump and RE trials, subjects performed a 30-minute treadmill run at a self-selected speed to induce fatigue. Subjects then repeated the jump and RE trials in the alternative shoe order. RESULTS: Oxygen consumption in the VP was lower when compared to the NS by 3.7% (31.8 ± 3 vs 33.6 ± 3 ml/kg/min p < 0.05) pre-fatigue and by 2.5% (32.5 ± 3 vs 33.3 ± 3 ml/kg/min p < 0.05) in the fatigued state, which is less than the anticipated 4% benefit. The pre- and post-fatigue reductions in oxygen consumption while wearing the VP were significantly different indicating the benefit of wearing the VP attenuated over time. Jump height in the VP was higher pre-fatigue (44.0 ± 6 vs 43.2 ± 6 cm, p < 0.05) but was not different in the fatigued state (43.8 ± 7 vs 43.6 ± 7 cm, p > 0.05) when compared to NS. CONCLUSION: Female runners experienced a similar improvement in RE while wearing the VP when compared to previous studies, however this improvement dropped to 2.7% following a relatively short fatiguing run. Thus, improvements in RE from the VP shoes may not extend through the entire duration of some running events in certain athletes.

Longitudinal bending stiffness does not affect running economy in Nike Vaporfly Shoes

PurposeThis study aimed to determine the independent effect of the curved carbon-fiber plate in the Nike Vaporfly 4% shoe on running economy and running biomechanics. MethodsFifteen 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. ResultsRunning 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 (MTP) joint with increased MTP dorsiflexion angle, angular velocity, and negative power in the VFcut. Contact time was 1% longer in the VFintact. ConclusionCutting 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.

Exploring the teeter-totter effect in shoes with curved carbon fibre plates

In recent times, the Nike Vaporfly 4% marathon shoe has been one of the most exciting shoes designed for competitive runners. It has been shown to lower the energetic cost of running on average by ...

Evaluating Ethical Awareness of Athletes About Disruptive Sport Techs: The Case of Nike Vaporfly Road Running Shoes

Evaluating Ethical Awareness of Athletes About Disruptive Sport Techs: The Case of Nike Vaporfly Road Running Shoes

Metabolic and performance responses of male runners wearing 3 types of footwear: Nike Vaporfly 4%, Saucony Endorphin racing flats, and their own shoes

PurposeWe 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. MethodsEighteen male recreational runners (age = 33.5 ± 11.9 year (mean ± SD), 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. ResultsOxygen consumption (mL/kg·min) was less 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). The 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. ConclusionOverall, 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.

Conceptualising a systems thinking perspective in sport studies

To date, applications of Systems Thinking (ST) in sport sciences are lacking with little existing practical work that adopted the approach. The aim of the article is to present an instantiation of ST in running towards demonstrating its utility. Two qualitative, principle tools in ST is demonstrated for a systemic problem in sport, namely recurring overuse injuries related to running. First, the growth-and-underinvestment system archetype is illustrated as a mechanism to differentiate short and long term solutions, incorporating the recent Nike Vaporfly running shoes and gait retraining. Secondly, a populated ice-berg model is provided of the runner and their environment: the runner-environment system is broken down into constituent units and then synthesised as the synergy between units; specifically considering the runner’s biomechanical properties, wearables and social media platforms. This article forms part of a more extensive project to contribute to a practical departure for ST in sport science; future work includes the quantified dynamic model of injury development from emergent interactions.