"Effect of Advanced Footwear Technology in Trail Running Shoes" by Jordan Sanders and Dustin P. Joubert
  •  
  •  
 

Abstract

Running economy (RE), a measure of a runner’s oxygen consumption or energy expenditure at a fixed speed, is an important endurance performance determinant. Advanced footwear technology (AFT), such as resilient and compliant midsole foams with an imbedded carbon-fiber plate, have previously been incorporated into road racing shoes to improve RE. AFT features are now being utilized in trail running shoes, but the efficacy has not been determined. PURPOSE: Determine the effect of an AFT trail running shoe on RE relative to a traditional trail shoe over trail and treadmill surfaces. METHODS: Eight runners reported for two separate visits, which included one session on a dirt/gravel trail outdoors and one session on a stiff treadmill indoors. Each visit, subjects completed 4 x 1500m trials wearing both an advanced shoe (AFT) and a control shoe (CTRL) in a duplicate, mirrored order. Thus, shoes were tested in either an ABBA or BAAB sequence, counterbalanced across subjects. Oxygen consumption (VO2) was measured with a calibrated portable metabolic cart, and the average values of the final 1000m of each 1500m trial were calculated. Subjects completed the trail running session first. They were directed to run the trials at self-selected 50k race effort. RE was calculated as VO2 expressed as cost of transport (CoT; ml/kg/km) to normalize for running speed. A high CoT is indicative of worse RE. Subjects completed the treadmill session ~1-2 weeks following the trail session. Treadmill speed was fixed to match the average speed of each individual subject’s trail trials. RE was analyzed by a 2-way (surface x shoe) repeated-measures ANOVA. RESULTS: There was a significant main effect for surface (p < .001) with the treadmill (209.0 ± 14.9 ml/kg/km) offering a 5.2 ± 2.3% CoT benefit relative to the trail (220.7 ± 16.1 ml/kg/km), independent of shoe. There was no significant effect for shoe (p = .105), but CoT was on average 1.0 ± 1.5% lower with AFT (208.1 ± 14.8 ml/kg/km) compared to CTRL (210.2 ± 15.6 ml/kg/km), independent of surface. There was also no surface x shoe interaction (p = .800), as the CoT benefit of AFT was 1.0 ± 1.1% over the trail and 0.8 ± 3.1% on the treadmill. CONCLUSION: We found that running overground on the trails significantly increased energy use regardless of shoe. While we did not see a significant benefit of AFT in trail shoes with the current sample of data, there is likely a small effect that can be observed with an expanded sample size. Nonetheless the magnitude of these effects (~1%) are smaller than those observed previously with AFT in road racing shoes (~2.7-4%) at faster speeds. Since there was not a difference in our data between the AFT trail shoe benefits on the trail vs. treadmill, this reduced benefit is not likely a surface effect. Instead, it may have more to do with the slower speeds tested, as we have previously shown a reduced benefit of AFT in road racing shoes at slower paces.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.