Development of novel calibration model(s) to predict whole-body density in professional football players
Introduction: Questions continue to be raised about the validity that is in existence to estimate Db, in professional male footballer players.
Methods: Phase 1: n = 28 anthropometric variables were used on n = 206 footballers, using regression analyses to determine standard error of estimate and R2. A cut-off correlation coefficient set at r = 0.950 and 90% R2. Phase 2: all variables (z-scores, x¯= 0.0, SD = ±1.0) to help reduce heteroscedasticity, ß, r, t, significance of t and P-values were calculated. Phase 3: a forced stepwise-backwards regression analysis approach with nine predictors which met the acceptance criteria (r = 0.950, R2 = 90% and ß weights) was used to develop a `best fit` and a `practical` calibration model. Phase 4: cross-validation of the two newly developed calibration method using LoA.
Results: The `best fit` model SEM (0.115 g ml-1), the highest R2 (6.6%) (P = 0.005), whereas the `practical` calibration model SEM (0.115 g ml-1), R2 (4.7%) (P = 0.005) with r values = 0.271 and 0.596 and R2 (%) coefficients = 0.3526 for the `best fit` and `practical` calibration models, respectively (P = 0.01).
Conclusions: The two calibration models supported an ecologically and statistically valid contribution and can provide sound judgements about professional footballers` body composition.
© Copyright 2024 Science and Medicine in Football. Taylor & Francis. All rights reserved.
| Subjects: | |
|---|---|
| Notations: | sport games biological and medical sciences |
| Tagging: | Regressionsanalyse |
| Published in: | Science and Medicine in Football |
| Language: | English |
| Published: |
2024
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| Online Access: | https://doi.org/10.1080/24733938.2023.2166680 |
| Volume: | 8 |
| Issue: | 2 |
| Pages: | 170-178 |
| Document types: | article |
| Level: | advanced |