When you start to work with a client, after you have assessed their health status, current level of physical activity, and symptoms that limit physical activity, its time to evaluate physical function and performance aka TEST! OR ASSESS!
Below is what your new clients should be able to do at a minimum.
6 or 8 m gait speed >0.6 m/s
8 sit-to-stand repetitions in 30s
8 arm curls with 4kg
Climbing 10 steps in under 30s
Chair sit & reach to the toes (0in) on both sides.
Moore, G., Durstine, J. L., Painter, P., & American College of Sports Medicine. (2016). Acsm's exercise management for persons with chronic diseases and disabilities, 4E. Human Kinetics.