Metabolic measures to ascertain the optimal load to be carried by man

As part of a combined electromyographic, mechanical work and metabolic study of load carriage this research focuses on the optimal load carried by the subject. This study demonstrates the anomalies associated with the definition of optimal load, and shows that it is dependent on whether or not the carrier is given any credit for carrying his own weight as well as that of the load. In many situations it may be important to include the carrier's own body mass in the optimal load equation. This study showed that if the load were body plus backpack the optimal backpack load was found to be quite low (less than 10kg) because the metabolic cosi increased quite rapidly at low loads. On the other hand, if the carrier's mass was ignored there might be an optimum load at 40 kg or higher. Giving partial ‘credit’ for carrying body weight (for example, 50% body mass plus backpack), resulted in an optimum load of about 17 kg. The percentage ‘credit’ given to the body mass itself depends on how important it is that the carrier does not arrive fatigued at his destination. The military may wish to give 100% credit, and recreational carriers zero.