bioRxiv Science⌕ Search

bioRxiv · 10.1101/2024.11.20.624520

Footwear-specific biomechanical and energetic responses to 8 weeks of training in advanced footwear technology

Abstract

BackgroundWhile the acute effects of advanced footwear technology (AFT) on running biomechanics and efficiency have been extensively studied, the longitudinal effects of AFT use are unknown. ObjectiveThe purpose of this study was to investigate the effects of using advanced footwear technology (AFT) versus traditional racing flats during running workouts on relative running economy (RE) and energetic cost (EC), and explore associations between changes in footwear-specific biomechanics and performance. MethodsThirteen competitive runners were randomly assigned Nike Vaporfly Next% 3 (VP) or Nike Rival Waffle 5 (FL) for an 8-week intervention and completed pre- (PRE) and post-intervention (POST) lab testing in both shoes. Weekly training data, including mileage, workouts, and soreness, were collected via questionnaires. Subjects ran two 3-min trials at a self-selected cross-country race pace, with sagittal plane ankle and metatarsophalangeal (MTP) joint kinematics and kinetics recorded and analysed. Subsequently, four 5-min trials were completed at a self-reported submaximal pace, in a randomized order, and shoe-specific RE and EC were calculated and reported as "VP% benefit" - the percentage RE or EC improvement in VP versus FL. Pearsons correlations were tested between RE outcomes and exploratory biomechanics measures, and independent samples t-tests tested for group differences in shoe-specific and overall efficiency changes from PRE to POST. ResultsVP% benefit increased from PRE to POST in VP trained runners and decreased in FL trained runners. VP trained runners decreased ankle plantarflexion velocity in VP, increased ankle dorsiflexion velocity in VP, and decreased MTP plantarflexion velocity in FL. Correlations revealed several significant associations between metabolic outcome measures, and biomechanical and training variables. ConclusionsMetabolic data support a footwear specificity of training principle (habituation), where training in VP may enhance a runners ability to benefit from VP on race day. Associations reveal that this may be due to changes in footwear-specific biomechanics at the ankle and MTP joints. Future research should explore the potential mechanisms through which runners adapt to AFT to maximize their performance benefits. Key PointsO_LIThe acute metabolic benefits and reduced mechanical demands in advanced footwear technology (AFT) have previously been demonstrated in distance runners. In an 8-week footwear intervention study, runners who trained in AFT increased their metabolic benefit from AFT and runners who trained in traditional racing flats decreased acute AFT metabolic benefits. C_LIO_LIChanges in ankle and metatarsophalangeal joint mechanics partially explain these changes in AFT metabolic benefits. C_LIO_LIData from this research support the findings of an earlier pilot study and replicate a habituation effect with AFT use during hard effort workouts, suggesting runners may consider using AFT prior to competition to maximize performance benefits. C_LI

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Matties, J. R., Kerr, J. D., Rowley, K. M.. 2024-11-22. Footwear-specific biomechanical and energetic responses to 8 weeks of training in advanced footwear technology. https://doi.org/10.1101/2024.11.20.624520

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Thoracoabdominal pressure transmission during prone and supine cardiopulmonary resuscitation in fresh-frozen human cadavers

Background: Prone cardiopulmonary resuscitation (CPR) may be necessary when turning a prone patient supine would delay chest compressions. Although prone compressions can generate arterial pressures comparable with or greater than supine CPR, the pathway of pressure transmission is uncertain. We examined synchronized intrathoracic, intra-abdominal, and central arterial pressures in both supine and prone positions. Methods: Two thawed fresh-frozen adult cadavers underwent three, 2-minute mechanical CPR trials per position in a counterbalanced crossover sequence. Solid-state catheters recorded pleural, peritoneal, and central arterial pressures simultaneously. Trial-level outcomes included peak pressure, mean pressure, pressure-time area, and the mean peritoneal-to-pleural pressure gradient. Exploratory fixed-effects models included position, cadaver, and their interaction. Results: Prone CPR increased peak intrathoracic pressure by 7.04 mmHg, peak intra-abdominal pressure by 21.69 mmHg, and peak arterial pressure by 15.40 mmHg. Mean intra-abdominal and arterial pressures increased by 16.22 and 9.90 mmHg, respectively. The mean peritoneal-to-pleural gradient reversed direction from -8.46 mmHg supine to 4.85 mmHg prone. Intrathoracic pressure-time area increased 3.4-fold, from 1.62 to 5.46 mmHg{middle dot}s, and arterial pressure-time area increased 2.2-fold, from 2.96 to 6.42 mmHg{middle dot}s. Conclusions: Compared to supine, prone mechanical CPR generated higher arterial pressures and reversed the pressure relationship across the thoracoabdominal boundary in both cadavers. Higher abdominal pressure coincided with a larger intrathoracic pressure-time area, a pattern compatible with reduced caudal pressure dissipation.

physiology↗

Genetic Variation, Iron Status, and FGF23 Signaling Converge to Regulate Renal Calcium Buffering in Sickle Cell Disease

Sickle cell disease (SCD) causes heterogeneous mineral imbalances including variable degrees of hypocalcemia. The kidney controls systemic calcium by reabsorbing calcium from the glomerular filtrate via paracellular transport and transcellular transport in the nephron tubules, yet it is unknown whether these processes are modulated by genetic or environmental factors or disrupted in SCD. Using SCD mouse models and single-cell multiomics, we identify the distal convoluted tubule (DCT) as the nephron segment most susceptible to calcium reabsorption dysfunction in SCD, mainly via reduction of calcium buffer protein calbindin 1 (CALB1). We show that CALB1 and its encoding mRNA are decreased in DCT cells in SCD, alongside decreased Klotho (KL)-dependent fibroblast growth factor (FGF) 23 signaling and intracellular calcium signaling. Dietary iron restriction reduces CALB1, KL, and calcium exporter SLC8A1 levels in SCD kidneys. Loss of CALB1 shifts DCT cells toward energy-inefficient glycolysis with the metabolite 2,3-diphosphoglycerate impairing KL-dependent FGF23 signaling to create a feed-forward loop suppressing calcium reabsorption. Analysis of gene expression and protein quantitative trait loci data from kidneys of genetically diverse mice revealed that Calb1 expression levels are highly heritable and co-regulated with Slc8a1, identifying a genetic axis that dictates differential capacities for calcium buffering and trafficking toward blood in the kidney. Together, these findings support a model in which genetic variation, dietary iron status, and FGF23 signaling converge on DCT calcium buffering to reduce renal calcium reabsorption in the SCD kidney. This points to personalized, genotype- and iron-dependent strategies for managing mineral metabolism in SCD patients.

physiology↗

Silver spoon effect: early-life environment and adult survival in a primate.

Early environmental conditions can have long-lasting effects on survival and reproductive fitness. Using a 23 year-long monitoring data set of captive mouse lemur's life history traits, we tested a relationship between maternal allocation to offspring (N = 1365) and their adulthood survival. Maternal characteristics such as age or body condition did not affect allocation to offspring whatever the litter size (1 to 3). Although birth mass depended on size and composition of the litters, mouse lemur survival was highly correlated with body mass acquired after weaning in both sexes, through potential sibling competition. Moreover, female's reproductive success correlated with this body mass and was consistently associated with increased longevity. These findings suggest the presence of a silver spoon effect under constant captive conditions. However, cumulative effects of genetic and adulthood social conditions strongly interact to affect adult survival. Deaths related to intra- or inter-sexes aggressive social interactions may outweigh effect of early environment and therefore minimize the silver-spoon effect on captive mouse lemur's survival. However, having a high body mass after weaning appeared to be a determinant factor in individual survival for mouse lemurs.

physiology↗