The 20 m shuttle run is not a valid test of cardiorespiratory fitness in boys aged 11–14 years. Issue 1 (22nd December 2019)

• Record Type: Journal Article
• Authors: Welsman, Jo; Armstrong, Neil
• Is Part Of: BMJ open sport & exercise medicine. Volume 5:Issue 1(2019)
• Publication Date: 2019-12-22
• Subjects: children -- exercise testing -- fitness testing; Sports medicine -- Periodicals; Exercise therapy -- Periodicals; 617.102705
• DOI: 10.1136/bmjsem-2019-000627
• Languages: English
• ISSNs: 2055-7647

Abstract

Abstract : Objectives: The 20 m shuttle run test (20mSRT) is used to estimate cardiorespiratory fitness (CRF) through the prediction of peak oxygen uptake (V ˙ O 2 ), but its validity as a measure of CRF during childhood and adolescence is questionable. This study examined the validity of the 20mSRT to predict peak V ˙ O 2 . Methods: Peak V ˙ O 2 was measured during treadmill running. Log-linear regression was used to correct peak V ˙ O 2 for body mass and sum of skinfolds plus age. Boys completed the 20mSRT under standardised conditions. Maximum speed (km/h) was used with age to predict peak V ˙ O 2 using the equation developed by Léger et al . Validity was examined from linear regression methods and limits of agreement (LoA). Relationships between 20mSRT performance and allometrically adjusted peak V ˙ O 2, and predicted per cent fat were examined. Results: The sample comprised 76 boys aged 11–14 years. Predicted and measured mass-related peak V ˙ O 2 (mL/kg/min) shared common variance of 32%. LoA revealed that measured peak V ˙ O 2 ranged from 15% below to 25% above predicted peak V ˙ O 2 . There were no significant relationships (p>0.05) between predicted peak V ˙ O 2 and measured peak V ˙ O 2 adjusted for mass, age and skinfold thicknesses. Adjusted for body mass and age, peak V ˙ O 2 was not significantly related (p>0.05) to 20mSRT final speed but a weak, statistically significant (r=0.24, p<0.05) relationship was found with peak V ˙ O 2 adjusted for mass and fatness. Predicted per cent fat was negatively correlated with 20mSRT speed (r=−0.61, p<0.001). Conclusions: The 20mSRT reflects fatness rather than CRF and has poor validity grounded in its flawed estimation and interpretation of peak V ˙ O 2 in mL/kg/min.