Human Energetics in Biological Anthropology (1995)
Stanley Jlijaszek's 1995 Human Energetics, showing the Gordon bag (1911) technique for measuring human energy expenditure for various activities. [2]
In science, human energetics refers to the study of humanity from the energetic point of view.

Etymology
In 1909, the term ‘human energetics’, a near-synonym to ‘human thermodynamics’, seems to have been attributed to German chemist Wilhelm Ostwald, who, in his Gross Manner, supposedly, he discusses how the ‘yield’ of mind’s of genius in society, such as Newton, Lavoisier, Goethe, or Helmholtz, depends on their chemical ‘economic coefficient’ or the ability to transform one kind of energy into another, or a type of ‘degradation’, mandated by the second law of thermodynamics. In this logic, according to Ostwald, some individuals are born into the world with the usual amount of energy, i.e. capacity for work, but are so constituted as to transform a large portion of it so that it is of service to humanity. [1]

In 1911, English physiologist Gordon Douglas proposed that gas analysis of expired air, such as by a person breathing into a “Douglas bag” via mouthpiece while performing a set activity for a known period, e.g. as depicted adjacent, would serve as an estimate of “human energy” expenditure. [2]

References
1. (a) W.R. (1909). “How to Diagnose Genius: A Study of Human Energetics”, Nature, pgs. 121-22, Jul 29.
(b) Ostwald, Wilhelm. (1909). Gross Manner. Leipzig: Akademische Verlagsgesellshaft.
2. (a) Douglas, C. Gordon. (1911). “A Method for Determining the Total Respiratory Exchange in Man” (pdf), Journal of Physiology, 42:17-23.
(b) Ulijaszek, Stanley J. (1995). Human Energetics in Biological Anthropology. Cambridge University Press.

Further reading
● Ulijaszek, Stanley J. (1995). Human Energetics in Biological Anthropology. Cambridge University Press.

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