International Journal of Medical and Health Research

International Journal of Medical and Health Research


International Journal of Medical and Health Research
International Journal of Medical and Health Research
Vol. 6, Issue 12 (2020)

Using multilevel linear growth models to examine participant performance on different cardiorespiratory fitness assessments


Peter D Hart

Background: The ability of a cardiorespiratory fitness (CRF) assessment to differentiate individuals is a valuable characteristic. Little research exists, however, regarding the extent to which individual variation in CRF differs in the same magnitude across different CRF tests. Purpose: The purpose of this study was to use multilevel linear growth models to examine the inter-individual variation of within-individual variation of CRF field test scores. Methods: Data for this research came from N=131 college students attending a rural public university. Four (4) CRF field assessments were administered to each participant in random order with each yielding estimated maximal oxygen consumption (VO2max, ml/kg/min). Random intercept and random slope multilevel growth models were evaluated with CRF tests (level 1) nested within participants (level 2). CRF tests were coded 0 = treadmill, 1 = step, 2 = non-exercise, and 3 = beep and sex was coded 1 = male and 0 = female. Results: Results from the unconditional means model justified the multilevel analysis of the CRF data (ICC = .19, p < .001). A fixed slope for CRF test (b = -4.95, p < .001) was significantly related to CRF scores but did not show significant random variation. A final random intercept model was selected with significant level 2 predictors of age (b = -0.33, p < .001) and sex (b = 12.59, p < .001), significant level 1 predictor of CRF test (b = -3.41, p < .001), and significant cross-level interaction predictor of sex-by-test (b = -2.32, p < .001). The final model explained 42% and 70% of level 1 and level 2 variance, respectively. Conclusion: Results from this study show that CRF field assessments suffer from considerable variation. Sex-specific inter-individual variation showed consistent within-person variation, with males displaying a slightly steeper linear trajectory across CRF tests.
Pages : 47-50 | 202 Views | 46 Downloads