Variables included for prediction of physical work capacity.

Selection of valid physical tests for prediction of firefighting physical work capacity (n = 36–38) using one laboratory and one field-test model. Before selection, the laboratory model included all laboratory tests and anthropometrics (X = 79); the field model included all field tests and anthropometrics (X = 18). Step 1, Variable Importance for the Projection (VIP): is showing variables included in model after the first selection. Step 2, Correlation: is showing variables included in the model after highly correlated (r ≥ 0.8) variables have been omitted. R2 indicates the overall fit of the model, and Q2 indicates the predictive power of the model. Field-test models were externally validated (EV) on another subject group (prediction-set: n = 90). VO2max: maximal oxygen uptake, J: Joule, NM: Newton meter, % HRmax: percentage of maximal heart rate used, s∙kg−1: time scaled to body mass.* The test was excluded from the EV because the prediction-set did not do the test.Variables included for prediction of physical work capacity.