Prevalence of Physical Activity Based on Energy Expenditure among US Adults Proposing 1,000 Kcal/week as an Alternative Goal

Abstract

PURPOSE: To analyze the national prevalence of exercise based on energy expenditure of ≤1,000 Kcal/week in the United States and to compare with CDC guidelines. METHOD: The National Health and Nutrition Examination Survey (NHANES) 1999–2002 contained a probability sample of U.S. adults, and its interviewed data on LTPA for the past 30 days were analyzed. For 10,268 subjects, metabolic equivalent tasks (MET) value was assigned to each reported LTPA activity, according to Ainsworth's compendium, and then converted to energy expenditure in kilocalorie (Kcal), taking body weight into consideration. RESULTS: For U.S. adults, the median energy expenditure was 40 Kcal/day, but was 155 Kcal/day for physically active individuals. More than half (56.5%) had no or limited LTPA, and one fifth (21.3%) of U.S. adults reported to be physically inactive. Only one quarter of the U.S. adults (24.2%) met the CDC recommendation, while nearly one third (31.7%) expended ≤1,000 Kcal/week, a goal suggested in Surgeon General's Report. The difference between two criteria came from “weekend warriors” who did not exercise regularly. CONCLUSION: Two thirds of U.S. adults did not reach 1,000 Kcal/week, known to be associated with lowered mortality. Invoking an alternative goal of ≤1,000 Kcal/ week, largely attainable through exercising 3 or 4 hours per week or 10,000 steps a day, will promote LTPA and recognize the efforts by the less frequent but more vigorous exercisers, such as “weekend warriors”.Table: The age-specific prevalence (%) of inactive, minimally active and active U.S. adults