A Preliminary Comparison of Muscle Oxygenation Measures via NIRS to Running Economy Changes Elicited by an Advanced Footwear Technology Intervention

Authors

Juliana G. Courville, University of Louisiana at LafayetteFollow
Dustin P. Joubert, University of Louisiana at LafayetteFollow

Abstract

Advanced footwear technology (AFT) has consistently been shown to improve running economy (RE) in laboratory settings, as reflected by a reduction in oxygen consumption (VO₂) at a given running speed. Traditionally, RE is measured with a metabolic cart; however, metabolic cart access is limited due to equipment cost and laboratory dependence. Recent technological advancements in near infrared spectroscopy (NIRS) provide a noninvasive means of assessing local muscle oxygen saturation (SmO₂) on the working muscle in real time and can be used in both laboratory and field settings. While previous literature has found similarities between NIRS data and other physiological parameters, this relationship is understudied, particularly in relation to RE. Should SmO₂ changes across a footwear intervention reflect RE changes, NIRS could be a useful, cost-effective tool in selecting footwear to optimize performance. PURPOSE: Determine if SmO₂ measured via NIRS reflects RE differences elicited by AFT. METHODS: Three competitive distance runners (2 male and 1 female) completed 4 x 5-minute running trials on a treadmill at their predicted marathon race pace with 5 minutes of recovery between trials wearing both an AFT shoe and control (CTRL) shoe. Across the 4 trials, participants alternated shoes as follows in a duplicate, mirrored order: CTRL, AFT, AFT, CTRL. Prior to the start of the protocol, participants completed a warmup to ensure physiological readiness and familiarization to lab equipment. During each running trial, SmO₂was measured via NIRS (Moxy Monitor) and RE was assessed by measuring VO₂ with a metabolic cart (ParvoMedics TrueOne 2400). The NIRS device was placed over the medial gastrocnemius following the manufacturer’s guidelines. This location was selected as AFT has been shown to impact work at the ankle and plantar flexors more than at the hip and knee. The average VO₂ and SmO₂ readings over the final 2 minutes of each 5-minute trial were calculated. These values were then averaged for the 2 trials of both the AFT and CTRL, and the percent differences between AFT and CTRL were determined. RESULTS: VO₂ (ml·kg^-1·min^-1) and SmO₂ (% muscle oxygenation) data were as follows: Subject 1 (VO₂: CTRL 50.9, AFT 48.6, -4.9% change; SmO₂: CTRL 19.7%, AFT 7.3%, -12.4% change), Subject 2 (VO₂: CTRL 44.1, AFT 43.2, -1.9% change; SmO₂: CTRL 47.3%, AFT 47.5%, 0.24% change), Subject 3 (VO₂: CTRL 48.3, AFT 46.2, -4.2% change; SmO₂: CTRL 23.5, AFT 24.1, 0.54% change). CONCLUSION: As expected, AFT improved RE for all 3 participants. However, differences in SmO₂ between AFT and CTRL shoes did not reflect the observed RE improvements. Although NIRS has potential as a non-invasive field-based monitoring device, its ability to detect RE changes associated with AFT remains unclear from this preliminary data. Future research should investigate these inconsistencies utilizing larger sample sizes and multiple NIRS monitors to assess more than one localized muscle site for the SmO₂ measures.

Recommended Citation

Courville, Juliana G. and Joubert, Dustin P. (2026) "A Preliminary Comparison of Muscle Oxygenation Measures via NIRS to Running Economy Changes Elicited by an Advanced Footwear Technology Intervention," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 222.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/222