Aging and Earth Gravity

As I've been taking care of the elderly patients day in day out for years,
one of the routine lectures to them is as follows.

"We are all earthlings, earth-bound, earth gravity bound creatures.
We don't feel earth gravity when we are young and active.
However, sooner or later aging process or long illness would conspire
with earth gravity to make us feel the earth gravity 24 hours a day.

The definition of physical fitness by doing aerobic exercise is basically
an effort to free ourselves from the earth gravity.
Certainly you will feel much freer and energetic if you are on the moon
which has less than one third of earth gravity.

As we enter 50's, our body needs 3 or 4 good exercise sessions a week
to maintain a reasonable freedom from the earth gravity.
In 60's perhaps we need to do it 5 or 6 times a week.
In 70's we need to do exercise once or twice a day depending
on our endurance.
In 80's we probably need to do it two to 4 times a day again depending
on our endurance.
In 90's we need to get up to move around every 15 min to 30 min
during waking hours with or without a cane or a walker.

If we stop fighting the earth gravity conspiring with the aging process,
the earth will certainly make sure that it will bury us sooner.
Besides walking or biking at various speed and strain, swimming
or water aerobic exercise does help us fighting the earth gravity
by partially neutralizing it so that we don't tax or strain our joints
and spines as much, which gives us less aches and pains and help us
saving the invaluable vanishing joint cartiliges and spine discs."

The above is the essence of my lecture to each elderly patient
I encounter in the office.
Now I have to eat every word I've been saying to the patients
as I became one of them.