In the same issue of Mayo Clinic Proceedings,
another related artice appears, its title being
"Perioperative Cognitive Decline in the Aging Population"

This article basically summarizes all the scientific evidences
in regard to how major surgeries and anesthetics for general and regional anesthesia
promotes, contributes to and causes the cognitive declines in seniors.
For examples, they have clear evidence that modern day anesthetics are
producing toxic proteins to the brain cells, etc, which indeed is disturbing.
Basically. seniors are better off by avoiding major surgergies if they want
to protect their brains, if possible.
Indeed, that's what I've been doing many years as an internist in order to protect
my patients from unnecessary surgeries.

I am glad to see this article as I try to do as much excercises as I can.

Among all excercises, I think the following kinds may be even better than others.

1. Hiking - Not like walking the street, it requires constant attention where your feet go next.
This uses up a lot of brain activities. It also requires constant balance control using our lower brains.
You can not just automatically and mechanically walk here.
I am pretty sure that hiking will increase the blood circulation in the legs as well as in the brain.

2. Golf - Just think about the frustration of not being able to hit the shot you want,
not to mention the stress of losing a few bucks for stupid mistakes.
This thing is more mental excercise than physical excercise.
Your philosophy of life changes up and down many times during a round. There's nothing like it.

3. Snow Skiing and boarding - Constant balance and body control are required while you are moving.
Then comes the pleasure that will surely turn the clock of age backward
and you will get younger each time and every time you ski.

4. Bycycling: Constant balance control and paying attention where you are going.

5. Rock Climbing - Though I do not recommend this to senior citizens,
this will demand most intensive brain excercise that no other sports can.
First of all, you have to be very smart (or idiotic ?) to do this. If you are dumb, forget it.

6. Tennis - This may be too tough for your knees, hips, elbows, and back.
But if you are able, this is a wonderful sport and brain excercise.

7. Wind Surfing for the same reasons.

8. I am sure there are many more but I am stopping here.
The main thing is you must use your mind as much as your muscles.

I am not sure about plain street walking or swimming where you hardly use your brain.
Anything you do in the fitness program in the Gym may be just waste of money and time.
(Please don't get mad at me. It's just my opinion !!)
Those things tend to be just excercises (like a caged squirrel running a wheel inside of it) only
and there's hardly any mental components.

Your hypothesis of combining aerobic exercises and brain exercise, perhaps being
more beneficial, is an interesting proposition.
As far as I know, there has been no study done to prove your theory, I believe.
All the studies mentioned in this articel dealt with the objective evidences of
benefits of aerobic exercise for brain.
Aerobic exercise by definition is exercise that is sufficient to increase the heart rate
and the need for oxygen, which can be measured by peak oxygen consumption
per unit time(VO2).

American Heart Association recommends,
"moderate-intensity aerobic physical activity for a minimum of 30 minutes on five days
each week or vigorous-intensity aerobic activity for a minimum of 20 minutes on
three days each week and resistance exercise for a minimum of two days each week."
Choice of exercise routines needs to be guided by patients' capabilities.

There was really no need to study (above article) about the plain excercises.
You simply turn around and look at the hard physical laborers.
They are doing a lot of excercises !! We just don't call it "excercise" but it is a legitimate excercise !!
Just study these people and compare with white-color workers. QED.
Why even bother to pick a few people as samples and watching them excercise?

For example, coal miners, farmers, day laborers, movers, strawberry pickers...
These mudane excercises have no intellectual, mental, psychological aspects in them.
Do they get older faster or slower than the general population?

To be a good study, you have to divide the subject in at least three categories.
1. Physical non-skilled laborer (automated and forced excercises with no self-entertainment or motivation)
2. Plain excercise such as running treadmills, simple walking, or any gym trainings with some self-motiation.
3. Excercise with skill and mental and intellectual elements with a lot of self-satisfaction.

Actually, we don't even have to study. We know the conclusion already, don't we?
My theory ends with "Excercises that make you happy" are the ones
that keep us from getting older.
Even though they are same excercises, playing golf is far better than picking strawberries
in keeping the senility from conquering us.
The sad thing in reality is, "can he afford to choose?"

To counter your point, farmers in Okinawa, Japan,
who do physical labors through their 80's and 90's
are well studied group of men and women who are reported to be
the longest livining people on Earth as a group.

As you know, exercise is only one determinant.
Diet is another, and life style such as smoking and drinking is another.
This study deals with one factor, i.e. aerobic exercise, relative to brain cognitive funtion,
 and all the other factors are equal and matched when compared with control group,
specifically, randomized controlled trials, that they reviewed.
You may certainly go to the article and read the entire text and see
if you would see their points more clearly.

Doc, I am not against the article at all.
What I am trying to say is :
If someone wants to improve or retain the cognitive brain function,
he should choose an exercise in which he runs the brain at the same time.

The authors are trying to say that there's some possibility
that it may be a good thing to do some aerobic excercise to stay in better mental and physical health.

So, I agree with them 100% but just added certain excercises that "may" improve the outcome better.
My theory (actually it's not even a theory) has not even been proven
and I have no intention (or resource) to prove it in scientific manner.
It's just a "raw" groundless speculation of mine.
My guess is that if we are going to spend money, time, and effort, we might as well pick the one
that may give us better results.
Instead of waiting for completed studies (by then we may be dead already),
let's do it right now (!!) and choose an excercise that might bring us a better result.
If my speculation turns out to be wrong, no harm is done because it is still an aerobic excercise.