A construct validation approach was followed to affirm that 8 physical ability test events were significantly related to two important constructs underlying the job performance of police officers: strength and endurance. A sample of 115 incumbent police officers took 8 physical ability tests and were rated by supervisors on their physical performances in their job. LISREL methods were used to test the model specified, and a reasonable fit was achieved. Portions of the model were tested on an independent sample of 161 applicants; the fit of the model was again acceptable. A nomological network of relationships, in which strength and endurance factors correlated in expected directions with other physiological and demographic variables, was hypothesized and tested. Finally, the data were examined for potential gender differences and bias. Considerable differences were shown between men and women on both test and performance variables, and women would be overpredicted if a common regression line were used for selection purposes.