And according to physical therapist, Leada Malek DPT, who recently authored Science of Stretch: Reach Your Flexible Potential, Stay Active, Maximize Mobility, “You can see how mobility plays a role in passing these tests, to a degree,” adding that while there are natural changes in body composition and muscle mass that occur as we age, the good news is, “skeletal muscle retains the ability to adapt, which means you can still build strength, muscle mass, and even train mobility [as you get older].”