Validation of a simplified physical activity record by doubly labeled water technique

Abstract

Introduction: For obtaining reliable information about physical activity in epidemiological studies, validated and easy-to-use instruments are required. Therefore, a new simplified physical activity record based on 15-min recording intervals was developed and validated.

Subjects: Nonobese volunteers (n = 31).

Measurements: Physical activity was recorded over a 7-day period without detailed instructions. Energy expenditure was calculated (EE(sPAR)) and compared to energy expenditure measured by doubly labelled water technique (EE(DLW)).

Results: A good agreement between EE(sPAR) (12.1+/-3.0) and EE(DLW) (11.7+/-3.3) with a mean difference of 0.33+/-1.55 MJ (r = 0.880, P < 0.001) was observed. The absolute difference between EE(sPAR) and EE(DLW) was < 10% in 65% of the subjects. The difference between EE(sPAR) and EE(DLW) was independent of gender, age, body weight, and body mass index. A weak positive association between the difference and total body fat was observed (r = 0.618, P < 0.001), suggesting a slight tendency to overestimate EE(sPAR) with increasing total body fat.

Conclusion: The new simplified physical activity protocol needs no detailed instructions, provides valid estimates of physical activity in nonobese free-living adults and can be used in epidemiological studies to assess total daily energy expenditure and physical activity level.