Strategies to improve running economy in trained distance runners

by Kyle Barnes

Institution: AUT University
Year: 2014
Keywords: Running economy; Running performance
Record ID: 1298206
Full text PDF: http://hdl.handle.net/10292/7125


Running economy is considered an important physiological measure for endurance athletes, especially distance runners. Of the numerous metabolic, cardiopulmonary, biomechanical and neuromuscular characteristics contributing to running economy, it seems that few are subject to alteration or improvement through training or other interventions. Over the past decade, various strategies to improve running economy have been investigated, but the evidence supporting different forms of movement-specific resistance exercises is limited and conflicting. Furthermore, there is a paucity of data evaluating the subsequent effects of changes in running economy on actual running performance. Given a range of mechanisms have been described as meditators to explain changes in running economy (Chapter 2) following various training strategies (Chapter 3) the initial aim of this thesis was to describe the determinants of running economy in a population analogous to that of which would participate in the ensuing experimental studies (Chapter 4). To determine factors and to assess the efficacy of different movement-specific resistance strategies to improve running economy and running performance, one descriptive and three experimental studies were conducted with a variety of methodological approaches to address the main aim of this thesis: to examine the relative efficacy of different forms of movement-specific resistance exercise to improve running economy and performance in competitive distance runners. The purpose of Chapter 4 was to evaluate the lower-body determinants of running economy among well-trained male and female distance runners. Leg stiffness (r = -0.80) and Achilles moment arm length (r = 0.90) had high to extremely high correlations with running economy and each other (r = -0.82), whereas correlations between running economy and kinetic measures (peak force, peak power and time to peak force) for both genders were unclear and biomechanical measures (stride rate, stride length, contact time, flight time) were small-moderate. At all common test velocities women were more economical than men (effect size (ES) = 0.40). The results of Chapter 4 suggested that while lower-body stiffness and Achilles moment-arm length were substantially related to the running economy of well-trained runners, no single lower-body measure could fully explain differences in running economy between individuals or genders. Running economy is therefore likely determined from the sum of influences from multiple lower-body attributes. The purpose of Chapter 5 was to determine the acute effects of wearing a weighted vest during warm-up "strides" on running economy, neuromuscular measures, and running performance. The weighted-vest condition resulted in a 6.0% improvement in running economy along with a 20% increase in leg stiffness, which resulted in a 2.9% enhancement in peak running speed. Relationships between change scores showed that changes in leg stiffness could explain all the improvements in performance and running economy. …