The mechanical efficiency of treadmill running against a horizontal impeding force

Area of Science:

• Biomechanics
• Exercise Physiology
• Sports Science

Background:

• Understanding running economy is crucial for athletic performance.
• Previous methods for assessing mechanical efficiency in running have limitations.
• Quantifying efficiency under load provides deeper insights into human locomotion.

Purpose of the Study:

• To describe a novel method for determining the apparent mechanical efficiency of running against a horizontal impeding force.
• To present findings from studies on three well-trained athletes using this method.
• To establish baseline values for load-running efficiency (LRE) and unloaded running energy cost (E(k)).

Main Methods:

• A linear relationship was established between metabolic rate and external work rate.
• Apparent mechanical efficiency was calculated as the inverse of the slope of the metabolic rate vs. external work rate regression line (x 10(2)%).
• Measurements were taken on three trained athletes under varying horizontal impeding forces.

Main Results:

• The overall mean apparent load-running efficiency (LRE) was 36.1%.
• Individual LRE differences were not statistically significant.
• No significant change in LRE was observed with habituation to the task.
• The overall mean net energy cost of unloaded horizontal treadmill running (E(k)) was 0.83 kcal. kg(-1). km(-1).

Conclusions:

• The described method provides a reliable measure of apparent mechanical efficiency during loaded running.
• The high and consistent LRE suggests efficient energy utilization in trained runners.
• Findings are compared with existing literature on running efficiency and isolated muscle studies.