EN ISO 8996:2004

Foreword
1 Scope
2 Normative references
3 Principle and accuracy
4 Level 1, screening
  4.1 Table for the estimation of metabolic rate by
      occupation
  4.2 Classification of metabolic rate by categories
5 Level 2, observation
  5.1 Estimation of metabolic rate by task requirements
  5.2 Metabolic rate for typical activities
  5.3 Metabolic rate for a work cycle
  5.4 Influence of the length of rest periods and work
      periods
  5.5 Obtaining values by interpolation
  5.6 Requirements for the application of metabolic-rate
      tables
6 Level 3, analysis
   6.1 Estimation of metabolic rate using heart rate
   6.2 Relationship between heart rate and metabolic rate
7 Level 4, expertise
   7.1 Determination of metabolic rate by measurement of
       oxygen consumption rate
   7.2 The doubly labelled water method for long-term
       measurements
   7.3 Direct calorimetry - Principle
Annex A (informative) Evaluation of the metabolic rate at
        level 1, screening
Annex B (informative) Evaluation of the metabolic rate at
        level 2, observation
Annex C (informative) Evaluation of the metabolic rate at
        level 3, analysis
Annex D (informative) Evaluation of the metabolic rate at
        level 4, expertise - Examples of the calculation of
        metabolic rate based on measured data

The metabolic rate, as a conversion of chemical into mechanical and thermal energy, measures the energetic cost of muscular load and gives a numerical index of activity. Metabolic rate is an important determinant of the comfort or the strain resulting from exposure to a thermal environment. In particular, in hot climates, the high levels of metabolic heat production associated with muscular work aggravate heat stress, as large amounts of heat need to be dissipated, mostly by sweat evaporation.ISO 8996:2004 specifies different methods for the determination of metabolic rate in the context of ergonomics of the climatic working environment. It can also be used for other applications -- for example, the assessment of working practices, the energetic cost of specific jobs or sport activities, the total cost of an activity, etc.