Estimating energy expenditure of head-hauling water and grain grinding from heart rate monitor measurements in northern Mozambique. Issue 16 (2nd November 2020)

• Record Type: Journal Article
• Authors: Russel, Kory C; Buman, Matthew P; Davis, Jennifer; Haskell, William L
• Is Part Of: Public health nutrition. Volume 23:Issue 16(2020)
• Page Start: 2886
• Page End: 2897
• Publication Date: 2020-11-02
• Subjects: Energy costs, -- Water fetching, -- Hand-pounding grain, -- Heart rate monitor, -- Indirect calorimetry, -- Metabolic equivalent of task, -- Rural Mozambican women; Nutrition -- Periodicals; Nutrition policy -- Periodicals; Public health -- Periodicals; 613.2
• DOI: 10.1017/S1368980020001019
• Languages: English
• ISSNs: 1368-9800

Abstract

Abstract: Objective: Even though sub-Saharan African women spend millions of person-hours per day fetching water and pounding grain, to date, few studies have rigorously assessed the energy expenditure costs of such domestic activities. As a result, most analyses that consider head-hauling water or hand pounding of grain with a mortar and pestle (pilão use) employ energy expenditure values derived from limited research. The current paper compares estimated energy expenditure values from heart rate monitors v . indirect calorimetry in order to understand some of the limitations with using such monitors to measure domestic activities. Design: This confirmation study estimates the metabolic equivalent of task (MET) value for head-hauling water and hand-pounding grain using both indirect calorimetry and heart rate monitors under laboratory conditions. Setting: The study was conducted in Nampula, Mozambique. Participants: Forty university students in Nampula city who recurrently engaged in water-fetching activities. Results: Including all participants, the mean MET value for head hauling 20 litres (20·5 kg, including container) of water (2·7 km/h, 0 % slope) was 4·3 (sd 0·9) and 3·7 (sd 1·2) for pilão use. Estimated energy expenditure predictions from a mixed model were found to correlate with observed energy expenditure ( r 2 0·68, r 0·82). Re-estimating the model with pilão use data excluded improved the fit substantially ( r 2 0·83, r 0·91). Conclusions: The current study finds that heart rate monitors are suitable instruments for providing accurate quantification of energy expenditure for some domestic activities, such as head-hauling water, but are not appropriate for quantifying expenditures of other activities, such as hand-pounding grain.