Effect of Vest Load Carriage on Cardiometabolic Responses with Load Position, Load Mass, and Walking Conditions for Young Adults

Carrying external loads, such as vest-borne systems, is common in occupations like firefighting and military service, yet the physiological impacts of load placement, mass, and walking conditions remain not fully understood. This study examined the effects of vest load carriage on metabolic rate and heart rate. Participants underwent three trials with varying load placements, masses (0-30 kg), and walking conditions (different speeds and inclines). Results showed no significant effect of load placement on metabolic and heart rates with a 10 kg vest load. When walking with a vest load at a speed of 5 km/h, the metabolic rate followed a quadratic relationship with load mass, while heart rate increased linearly. When walking with a 10 kg vest load, with slope ranging from 0% to 10% and speed ranging from 3 km/h to 7 km/h, each 5% increase in slope or 2 km/h increase in speed significantly elevated the metabolic rate. These findings highlight the importance of load mass in determining energy expenditure and can guide safer load-bearing designs.