The Claim
The metabolic cost of walking with a load is not fully explained by mechanical work on the center of mass, as approximately 84% of the increased energy expenditure remains unaccounted for by work, suggesting additional metabolic contributions such as muscle activation, balance control, or soft tissue dynamics.
What the research says
Challenges is higher
Challenge is ahead, but a single strong supporting study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
When walking with a load, the body uses more energy than can be explained by the mechanical work done to move the center of mass; about 84% of this extra energy use comes from other biological processes such as muscle activation, balance control, or soft tissue movements.
See the scientific wording
The metabolic cost of walking with a load is not fully explained by mechanical work on the center of mass, as approximately 84% of the increased energy expenditure remains unaccounted for by work, suggesting additional metabolic contributions such as muscle activation, balance control, or soft tissue dynamics.
When a person carries a heavy load, their body has to push and pull more mass with each step, forcing leg muscles to work harder to move the center of mass. This extra work requires muscles to burn more fuel because muscles are inefficient—they use far more energy to produce movement than the movement itself requires. Almost all the extra energy used comes from this inefficiency, not from balancing or other hidden factors.
What the research says
1 studyStudy: Mechanics and energetics of load carriage during human walking
When people carry heavy backpacks, they use more energy—but this study found that most of that extra energy use can be explained by the physical work their legs do, not by mysterious extra factors like balance or muscle effort. So it actually disagrees with the idea that most of the energy cost is unexplained.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.