Related Experiment Video
Updated: Jun 10, 2026
09:20
Assessing Energy Substrate Oxidation In Vitro with 14CO2 Trapping
Published on: March 23, 2022
Fuel oxidation at the walk-to-run-transition in humans
Kathleen J Ganley1, Anthony Stock, Richard M Herman
1Department of Physical Therapy and Athletic Training, Northern Arizona University, Flagstaff, AZ, USA.
Metabolism: Clinical and Experimental
|August 17, 2010
Summary
Transitioning from walking to running conserves carbohydrates. This gait change, influenced by perceived effort, enhances metabolic efficiency and may be an evolutionary adaptation for energy conservation.
Area of Science:
- Human locomotion
- Exercise physiology
- Biomechanics
Background:
- The walk-to-run transition involves multiple factors like anthropometrics and energetics.
- Metabolic fuel source has not been extensively studied as a factor in gait transition.
Purpose of the Study:
- To investigate the role of metabolic fuel source in the human walk-to-run transition.
- To determine how gait transition affects fuel oxidation and perception of effort.
Main Methods:
- Indirect calorimetry measured fuel oxidation rates in 10 adults.
- Participants locomoted on a treadmill at various speeds under three conditions: unconstrained gait, walking only, and running only.
- Perception of effort was recorded throughout the trials.
Main Results:
- The preferred walk-to-run transition speed was 2.08 ± 0.03 m/s.
- Transitioning from walking to running increased oxygen consumption.
- Gait transition decreased the perception of effort and reduced carbohydrate oxidation rate.
Conclusions:
- Gait transition from walking to running is a carbohydrate-sparing strategy.
- Perception of effort appears to guide this transition, potentially as an evolutionary energy conservation mechanism.
Related Concept Videos
01:15Pyruvate Oxidation
After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
01:20Energy-requiring Steps of Glycolysis
Glucose is the source of nearly all energy used by organisms. The first step of converting glucose into usable energy is called glycolysis. Glycolysis occurs in the cytosol of the cell over two phases: an energy-requiring phase and an energy-releasing phase. Over the first three steps, glucose is converted into different forms and attached to two phosphate groups donated by two ATP molecules, resulting in an unstable sugar. In the next two stages, the unstable sugar splits into two sugar...
01:24Other Glycolytic Pathways
The pentose phosphate pathway (PPP) operates in parallel with glycolysis, facilitating the metabolism of both pentoses and glucose. This pathway consists of two distinct phases: the oxidative and non-oxidative phases. While it does not directly generate ATP, the intermediates formed during the process can integrate into glycolysis, contributing to cellular energy metabolism when required.Oxidative Phase: NADPH ProductionThe oxidative phase of the pentose phosphate pathway is primarily...
01:28Energy-releasing Steps of Glycolysis
Glycolysis is divided into two phases based on whether energy is utilized or released. While the first phase consumes ATP, the second phase produces energy in the form of ATP and NADH. The energy is released over a sequence of reactions that turns G3P into pyruvate. The energy-releasing phase—steps 6-10 of glycolysis—occurs twice, once for each of the two 3-carbon sugars produced during steps 1-5 of the first phase.
The first energy-releasing step—the 6th step of glycolysis —consists of two...
The first energy-releasing step—the 6th step of glycolysis —consists of two...
01:19Phase I Oxidative Reactions: Overview
Phase I biotransformation, or functionalization, is a crucial chemical process that converts drugs and other xenobiotics into more water-soluble forms, facilitating expulsion from the body. It involves oxidative, reductive, and hydrolytic reactions that add or unveil polar functional groups on lipophilic substrates. Key players in phase I reactions are the mixed-function oxidases. Situated in liver cell microsomes, these enzymes predominantly carry out drug metabolism. They require molecular...
01:30The Electron Transport Chain
The electron transport chain or oxidative phosphorylation is an exothermic process in which free energy released during electron transfer reactions is coupled to ATP synthesis. This process is a significant source of energy in aerobic cells, and therefore inhibitors of the electron transport chain can be detrimental to the cell's metabolic processes.
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q in...
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q in...