Estimating Energy Expenditure during Level, Uphill, and Downhill Walking

Area of Science:

• Biomechanics
• Human energy expenditure
• Exercise physiology

Background:

• The Load Carriage Decision Aid (LCDA) walking equation was developed using aggregated group data for estimating energy expenditure during standing and level walking in healthy adults.
• This equation has not been validated for individual use or for graded walking conditions.

Purpose of the Study:

• To validate the LCDA walking equation for predicting standing and level walking energy expenditure in individuals.
• To develop and validate a new LCDA graded walking equation for estimating energy expenditure during uphill and downhill walking.

Main Methods:

• Compiled energy expenditure data from 95 participants across 11 studies, including standing, level, and graded walking (grades from -40% to 45%).
• Validated the existing LCDA walking equation against aggregated standing and level walking data.
• Developed and cross-validated a new LCDA graded walking equation using the compiled data.
• Compared the LCDA equations against four other predictive equations using the standard error of estimation (SEE).

Main Results:

• The LCDA walking equation demonstrated accurate estimation of standing and level walking energy expenditure (SEE = 0.20 W·kg).
• The addition of a novel grade term resulted in precise estimation of uphill and downhill walking energy expenditure (SEE = 0.42 W·kg).

Conclusions:

• The LCDA walking equation is a validated tool for predicting energy expenditure during standing and walking in healthy, military-age individuals.
• A new, single LCDA graded walking equation effectively estimates energy expenditure across level, uphill, and downhill walking conditions.
• This new equation provides a practical tool for practitioners to calculate energy expenditure in diverse walking scenarios.