title: [Energy expenditure at physical activities of young and middle-aged adults in southern China].
abstract: OBJECTIVE
  To investigate the energy expenditure at physical activities of young and middle-aged adults in southern China.
  
  
  METHODS
  64 healthy young and middle-aged adults living on light physical activity intensity were recruited by questionnaire and physical examination. A Cosmed k4b2 portable metabolic unit was used to measure the oxygen consumption (Vo2) and carbon dioxide production (Vco2) at a status of basic metabolism and during seven physical activities, including slow walking, brisk walking, walking upstairs, walking downstairs, watching TV, jogging and bicycling. The urinary nitrogen excreted in 24 hours was detected by a standard Kjeldahl method. Energy expenditure at physical activities was calculated by Weir equation.
  
  
  RESULTS
  The energy expenditure (kJ x h(-1) x kg(-1)) at physical activities were 14.77 +/- 2.47 for slow walking, 22.18 +/- 3.68 for brisk walking, 41.34 +/- 7.32 for jogging, 18.41 +/- 3.89 for bicycling, 26.11 +/- 4.18 for walking upstairs, 13.68 +/- 2.89 for walking downstairs and 5.06 +/- 1.09 for watching TV. The energy expenditure of males at physical activities was higher than those of females (P < 0.05).
  
  
  CONCLUSIONS
  There is a significant difference among energy expenditures at different physical activities; watching TV is a physical activity in light intensity; slow walking, brisk walking, walking upstairs, walking downstairs and bicycling are physical activities in moderate intensity, and jogging is a vigorous physical activity.
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu 610041, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Yu
authors.forename: Guo
authors.initials: G
authors.lastname: Zeng
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Deqian
authors.initials: D
authors.lastname: Mao
authors.forename: Chengyu
authors.initials: C
authors.lastname: Huang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Piao
authors.forename: Hongxia
authors.initials: H
authors.lastname: Guo
authors.forename: Gaiping
authors.initials: G
authors.lastname: Cheng
authors.forename: Min
authors.initials: M
authors.lastname: Peng
mesh_terms: D000328:Adult; D002681:China; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D012016:Reference Values; D012737:Sex Factors; D011795:Surveys and Questionnaires; D055815:Young Adult