The effect of Load Bearing either on the back or on the Chest on Oxygen Consumption and Energy Expenditure
AbstractChanges in arterial blood pressure, pulse rate, oxygen consumption and energy expenditure have been investigated in healthy young women (aged between 19.0 years to 24.0 years) at rest or while walking a distance of 76.5 meters within two minutes on a horizontal plane. These measurements were taken with no load bearing, with load bearing on the back and then on the chest. The weight of the load was 6.4 kg.
Results showed that without bearing load, walking increased pulse rate by 11.3 ± 1.3% (p < 0.05), oxygen consumption rate by 28.4 ± 2.5% (P<0.05) and energy expenditure by 28.6 ± 2.3% (P<0.05) when compared with measurements taken at rest. Oxygen consumption rate increased by 37.2 ± 3.0% (p < 0.01) when the weight was strapped to the back and by 62.0 ± 2.0% (p < 0.001) when the weight was strapped to the chest. Similarly, energy expenditure was significantly higher (p < 0.001) when the weight was strapped to the chest (64.7 ± 1.2%) than when it was strapped to the back (41.2 ± 3.5%). Increase in pulse rate was also significantly higher (p < 0.01) when the weight was strapped to the chest (10.0 ± 0.7%) than when it was strapped to the back (2.6 ± 0.5%). Arterial blood pressure changes were similar. Results of this study show that load bearing on the back is less energy demanding than load bearing on the chest.
Key words: Load bearing, back, chest, oxygen consumption, energy expenditure.
[Nig. Jnl Health & Biomedical Sciences Vol.1(1) 2002: 41-44]