What does each test measures in physical fitness?

Answer 1

Pacer measures speed/endurance, trunk lift measures flexibility, the mile run measures primarily endurance, but speed as well, curl ups test muscular endurance (in your abdominal area to be exact), the flex arm hang tests muscular endurance in your biceps, and push ups test muscular endurance in your arms as well.

Answer 2

physical activity that the body partakes in has a scientific basis.