Running Economy from a Muscle Energetics Perspective

Area of Science:

• Exercise Physiology
• Biomechanics
• Skeletal Muscle Energetics

Background:

• Traditional quantification of running economy uses mass-specific oxygen uptake.
• Fuel substrate usage varies with exercise intensity, necessitating metabolic energy units for accuracy.
• The energy cost of running (Erun) is fundamentally linked to skeletal muscle contraction energetics.

Purpose of the Study:

• To review key features dictating the energy cost of distance running.
• To approach the study of Erun from the perspective of skeletal muscle energetics.
• To understand factors influencing Erun, considering both trainable and non-trainable elements.

Main Methods:

• Review of scientific literature on running economy and skeletal muscle energetics.
• Analysis of factors influencing skeletal muscle contraction (force, duration, velocity, length).
• Categorization of Erun determinants into trainable and non-trainable factors.

Main Results:

• Erun is determined by the energy required for skeletal muscle contraction.
• Non-trainable factors include environmental conditions, surface characteristics, and some anthropometric features.
• Trainable factors include other anthropometric features, muscle/tendon properties, and running mechanics.

Conclusions:

• Expressing running economy in metabolic energy units provides a more accurate understanding of Erun.
• Skeletal muscle energetics are central to determining the energy cost of running.
• Training can alter specific factors that influence Erun, highlighting potential for performance improvement.