Oh how I dislike hearing people say "Boy, it sucks getting old!" It doesn't have to suck! I DO NOT believe that aging necessarily means life will get worse. Yes, there are some certainties with aging: graying hair, skin loses elasticity, metabolism slows down. But stooped posture, limited movement and needing a cane or walker are not natural results of aging.
Have you every been told "well, you're not getting any younger" when you are faced with some functional issues, or when you express you wish you could do "X"? (insert name of sport or activity that you used to do).
This is a common thing to hear which is part of this traditional myth that as you get older you start to slow down.
Any weakening or deterioration of our bodies takes place gradually - NOT because of aging but because of what you no longer do as you age.
"Use it or lose it!"
The thing is, we move differently when we are adults vs when we are children. We no longer run, jump, roll, climb or do somersaults. The problem with this is that once you stop doing these things, you lose the ability to do them. This is because your brain, which is a highly responsive organ of adaptation, adjusts to this lack of activity. If certain activities are no longer part of your life, your brain crossed them off the list. In a word, it forgets. This is called Sensory Motor Amnesia.
Regular and varied physical activity is necessary to maintain both the function and structure of the human body. If your bones aren't regularly used to bear significant weights and to support strong forces, they become soft. If your muscles aren't regularly used in challenging and skilled activities, they become weaker and less responsive. If your brain cells aren't regularly involved in a wide variety of voluntary activities, they deteriorate.