title: Measurement of cardiorespiratory fitness in children from two commonly used field tests after accounting for body fatness and maturity.
abstract: Body fat and maturation both influence cardiorespiratory fitness, however few studies have taken these variables into account when using field tests to predict children's fitness levels. The purpose of this study was to determine the relationship between two field tests of cardiorespiratory fitness (20 m Maximal Multistage Shuttle Run [20-MST], 550 m distance run [550-m]) and direct measurement of VO2max after adjustment for body fatness and maturity levels. Fifty-three participants (25 boys, 28 girls, age 10.6 ± 1.2 y, mean ± SD) had their body fat levels estimated using bioelectrical impedance (16.6% ± 6.0% and 20.0% ± 5.8% for boys and girls, respectively). Participants performed in random order, the 20-MST and 550-m run followed by a progressive treadmill test to exhaustion during which gas exchange measures were taken. Pearson correlation coefficient analysis revealed that the participants' performance in the 20-MST and 550-m run were highly correlated to VO2max obtained during the treadmill test to exhaustion (r = 0.70 and 0.59 for 20-MST and 550-m run, respectively). Adjusting for body fatness and maturity levels in a multivariate regression analysis increased the associations between the field tests and VO2max (r = 0.73 for 20-MST and 0.65 for 550-m). We may conclude that both the 20-MST and the 550-m distance run are valid field tests of cardiorespiratory fitness in New Zealand 8-13 year old children and incorporating body fatness and maturity levels explains an additional 5-7% of the variance.
authors.affiliation: Department of Social Science, Parks, Recreation, Tourism and Sport, Lincoln University, Christchurch, New Zealand.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hamlin
authors.affiliation: Department of Social Science, Parks, Recreation, Tourism and Sport, Lincoln University, Christchurch, New Zealand.
authors.forename: Meegan
authors.initials: M
authors.lastname: Fraser
authors.affiliation: Department of Social Science, Parks, Recreation, Tourism and Sport, Lincoln University, Christchurch, New Zealand.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Lizamore
authors.affiliation: School of Sciences and Physical Education, University of Canterbury, Christchurch, New Zealand.
authors.forename: Nick
authors.initials: N
authors.lastname: Draper
authors.affiliation: School of Applied Sciences and Allied Health, Christchurch Polytechnic Institute of Technology, Christchurch, New Zealand.
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Shearman
authors.affiliation: School of Applied Sciences and Allied Health, Christchurch Polytechnic Institute of Technology, Christchurch, New Zealand.
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Kimber
keywords: VO2max; aerobic performance; cardiorespiratory fitness; children; endurance