Total energy expenditure estimated using a foot-contact pedometer

Area of Science:

• Exercise Physiology
• Biomedical Engineering
• Human Kinetics

Background:

• Total energy expenditure (TEE) assessment is crucial for understanding human metabolism.
• Doubly labeled water (DLW) is a gold standard but expensive and complex.
• Pedometry offers a potentially simpler and more cost-effective alternative for TEE assessment.

Purpose of the Study:

• To evaluate a novel pedometry-based method (TEEpedo) for estimating TEE.
• To compare the accuracy of TEEpedo against the established DLW method (TEEdlw).
• To determine the conditions under which TEEpedo provides reliable TEE measurements.

Main Methods:

• A cohort of 7 men and 10 women shipboard sailors participated in an 8-day study.
• TEE was estimated using TEEpedo, incorporating total body weight, foot-ground contact times (Tc) during various activities (running, walking, NEAT), and resting metabolic rate (RMR).
• RMR was calculated from lean body mass, and activity energy cost was derived from Tc and time spent in each activity.

Main Results:

• The TEEpedo method explained 79% of the variance in TEE compared to TEEdlw.
• Mean TEE estimated by TEEpedo (12.65+/-3.1 MJ/day) did not significantly differ from the mean TEEdlw (12.55+/-3.3 MJ/day).
• The 95% confidence interval for TEEpedo relative to TEEdlw was +/-0.81 MJ/day.

Conclusions:

• The TEEpedo method provides accurate TEE estimates for moderate energy expenditure levels (9-14 MJ/day).
• At higher TEEs (>14 MJ/day), TEEpedo tended to underestimate actual expenditure, potentially due to unmeasured upper body movements.
• This pedometry-based approach offers a promising, less invasive alternative for TEE assessment in specific contexts.