A Comparison of the Energetic Cost of Running in Marathon Racing Shoes

Abstract

BackgroundReducing 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.ObjectiveThe 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).ConclusionThe 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.

Adding carbon fiber to shoe soles does not improve running economy: a muscle-level explanation

“…35 This increased footwear bending stiffness and shortened ankle-joint moment arm may be related to Nike’s curved carbon-fiber midsole plates. 38 Additionally, compared to the Adidas footwear, the respective Nike soles are 8 mm taller (35-62% taller depending on midsole location), the midsole foam is roughly half as stiff (in-series linear stiffness, not bending), and its hysteresis is 11.1% less during vertical loading and unloading. 38 Because both decreased midsole foam linear stiffness 39–41 and relative mechanical energy dissipation 42 in-series to the stance-limb are associated with more economical running, Nike footwear may elicit superior running economy values than Adidas footwear due to their relatively compliant and resilient midsole foam – not increased bending stiffness.…”

“…If footwear bending stiffness does not affect running economy, why does wearing Nike footwear with carbon fiber plates embedded in their midsole (Nike) improve running economy compared to wearing Adidas footwear? 38 Perhaps Nike’s carbon fiber plate provide the structure necessary for the midsole foam to function. For instance, despite a 264% increased bending stiffness, when athletes run in Nike’s they elicit slightly shorter GRF to ankle-joint moment arms compared to running in Adidas footwear.…”

Does an increase in energy return and/or longitudinal bending stiffness shoe features reduce the energetic cost of running?

“…These previous studies in the field of footwear have led Hoogkamer et al (2017b) to propose that the combination of weight saving, high midsole material energy return, and high longitudinal bending stiffness in a same pair of shoes was potentially beneficial to improve the RE. A recent study has been the first to test this assumption by combining high energy return midsole material with high longitudinal bending stiffness in a same pair of shoes and has reported an improved RE over the average group of participants compared to baseline marathon racing shoes (Hoogkamer et al 2017a). However, because the compared shoes conditions came from different brands, they varied in other features such as the midsole stiffness in compression, the midsole geometry, and upper shoe characteristics that may also influence the previously reported RE improvements.…”

Connecting the legs with a spring improves human running economy

“…Another passive assistance strategy involves using springs in parallel with the legs [15], [16], but this approach has yielded mixed results. Most recently, a shoe with carbon fiber springs embedded in the sole resulted in a 4% improvement in running economy [17], the largest savings for a self-contained system across all devices that target stance.…”