The concept of human performance is used in occupational medicine and occupational science and in many other contexts. Performance is attributable to physical, sensory, cognitive and psychological performance prerequisites. When considering physical performance, interactions with other levels of human performance including resilience must be taken into account. Physical performance prerequisites (also called conditional abilities & x202f;= main motor forms of stress) include endurance, strength, speed, coordination and flexibility. The assessment of a concrete work-related performance with performance diagnostic test methods only reflects partial aspects of real performance; therefore, performance cannot be ultimately measured by the testing of single components. Test procedures are all the more meaningful the more realistic the tests simulate the corresponding workloads. Performance tests predominantly test the maximum achievable performance in each case; however, professional work is usually not carried out at the maximum possible performance limit but at a submaximal level, with the remaining performance reserves varying from individual to individual. Results of tests and standard values for maximum performance (e.g. vita maxima tests, maximum forces, etc.) are to be interpreted accordingly. The evaluation of the test results of performance requires a reference to normal values, which are differentiated according to gender and age. Employees over the age of 50 years should be considered. The concept of "persons with normal capacity to work under pressure" as a generic term for a group of persons for whom living conditions should be acceptable from a health point of view without special regard for the individual person, continues to have a practical significance. Examinations of the physical performance in the sense of aptitude diagnostics are only permissible on the basis of labor law-related legal foundations in the case of special requirements, where the protection of third parties is prioritized.