Alan M Nevill1, Roger Ramsbottom2, Gavin Sandercock3, Carlos Eduardo Bocachica-González4, Robinson Ramírez-Vélez5, Grant Tomkinson6,7. 1. Faculty of Education, Health and Wellbeing, University of Wolverhampton, Walsall Campus, Walsall, UK. a.m.nevill@wlv.ac.uk. 2. Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK. 3. School Sport, Rehabilitation and Exercise Science, University of Essex, Colchester, UK. 4. La Victoria, Institución Educativa Distrital, Secretaria de Educación del Distrito, Bogotá, Colombia. 5. Department of Health Sciences, Public University of Navarra, Navarrabiomed-IdiSNA, Complejo Hospitalario de Navarra (CHN), 31008, Pamplona, Spain. 6. Department of Education, Health and Behavior Studies, University of North Dakota, Grand Forks, ND, USA. 7. Alliance for Research in Exercise, Nutrition and Activity (ARENA), School of Health Sciences, University of South Australia, Adelaide, SA, Australia.
Abstract
BACKGROUND AND OBJECTIVES: Doubts have been raised concerning the validity of the 20-m shuttle-run test (20 mSRT) as a predictor of cardiorespiratory fitness (CRF) in youth based on Léger's equation/model. An alternative allometric model has been published recently that is thought to provide, not only a superior fit (criterion validity) but also a more biologically and physiologically interpretable model (construct validity). The purposes of this study were to explore whether allometry can provide a more valid predictor of CRF using 20 mSRT compared with Léger's equation/model. METHODS: We fitted and compared Léger's original model and an alternative allometric model using two cross-sectional datasets (youth, n = 306; adult n = 105) that contained measurements of CRF ([Formula: see text]/[Formula: see text]) and 20 mSRT performance. Quality-of-fit was assessed using explained variance (R2) and Bland and Altman's limits of agreement. RESULTS: The allometric models provided superior fits for the youth (explained variance R2 = 71.9%) and adult (R2 = 77.7%) datasets compared with Léger's equation using their original fixed (R2 = 35.2%) or re-estimated parameter models (R2 = 65.9%), confirming that the allometric models demonstrate acceptable criterion validity. However, the allometric models also identified a non-linear "J-shaped" increase in energy cost ([Formula: see text]/[Formula: see text]) with faster final shuttle-run speeds (fitted speed exponent = 1.52; 95% CI 1.38-1.65). CONCLUSION: Not only do allometric models provide more accurate predictions of CRF ([Formula: see text]/[Formula: see text]; ml kg-1 min-1) for both youth and adults (evidence of criterion validity), the "J-shaped" rise in energy demand with increasing final shuttle-run speed also provides the evidence of construct validity, resulting in a more plausible, physiologically sound, and interpretable model.
BACKGROUND AND OBJECTIVES: Doubts have been raised concerning the validity of the 20-m shuttle-run test (20 mSRT) as a predictor of cardiorespiratory fitness (CRF) in youth based on Léger's equation/model. An alternative allometric model has been published recently that is thought to provide, not only a superior fit (criterion validity) but also a more biologically and physiologically interpretable model (construct validity). The purposes of this study were to explore whether allometry can provide a more valid predictor of CRF using 20 mSRT compared with Léger's equation/model. METHODS: We fitted and compared Léger's original model and an alternative allometric model using two cross-sectional datasets (youth, n = 306; adult n = 105) that contained measurements of CRF ([Formula: see text]/[Formula: see text]) and 20 mSRT performance. Quality-of-fit was assessed using explained variance (R2) and Bland and Altman's limits of agreement. RESULTS: The allometric models provided superior fits for the youth (explained variance R2 = 71.9%) and adult (R2 = 77.7%) datasets compared with Léger's equation using their original fixed (R2 = 35.2%) or re-estimated parameter models (R2 = 65.9%), confirming that the allometric models demonstrate acceptable criterion validity. However, the allometric models also identified a non-linear "J-shaped" increase in energy cost ([Formula: see text]/[Formula: see text]) with faster final shuttle-run speeds (fitted speed exponent = 1.52; 95% CI 1.38-1.65). CONCLUSION: Not only do allometric models provide more accurate predictions of CRF ([Formula: see text]/[Formula: see text]; ml kg-1 min-1) for both youth and adults (evidence of criterion validity), the "J-shaped" rise in energy demand with increasing final shuttle-run speed also provides the evidence of construct validity, resulting in a more plausible, physiologically sound, and interpretable model.
Authors: Grant R Tomkinson; Justin J Lang; Luc A Léger; Timothy S Olds; Francisco B Ortega; Jonatan R Ruiz; Mark S Tremblay Journal: Br J Sports Med Date: 2019-02-06 Impact factor: 13.800
Authors: Alan M Nevill; Roger Ramsbottom; Gavin Sandercock; Carlos Eduardo Bocachica-González; Robinson Ramírez-Vélez; Grant Tomkinson Journal: Sports Med Date: 2021-05-20 Impact factor: 11.136
Authors: Shawnda A Morrison; Vedrana Sember; Bojan Leskošek; Marjeta Kovač; Gregor Jurak; Gregor Starc Journal: Front Physiol Date: 2021-03-08 Impact factor: 4.566