Power Foods for the Brain (15 page)

Your target zone is between 60 percent and 80 percent of your maximal pulse. When you are starting out, aim for 60 percent of your maximum heart rate (for a sixty-year-old, that would be 96 beats per minute). When you are in better shape, you can push to 70 to 80 percent of your maximum heart rate—for a sixty-year-old, that would be 112 to 128 beats per minute. A highly trained athlete might push to 85 percent, but no one should go beyond that level. The table below will help you find your zone.

The idea of a target pulse zone is a welcome one for people who loathe the notion of jogging down the road for some interminable distance. Instead, you’re just keeping your pulse up for a certain period of time. You can stop whenever you’re uncomfortable and start again when you’re ready.

Again, don’t push it. Be sure to talk about your exercise plans with your doctor and follow his or her recommendations. It is important that you are comfortable as you exercise, can easily breathe and speak, and have no sensation of pain.

If you are in good shape now, a good way to begin is with a thirty-minute brisk walk three times per week. If you are not accustomed to brisk walking, you can start with just a ten-minute walk, and increase by five minutes each week. So during the first week, each walk lasts ten minutes. Feel free to walk more than once a day, but keep each walk within your limits. The second week, each walk lasts fifteen minutes, and so on until you reach forty or forty-five minutes. Then stay at that duration, with walks three or more times a week.

As you walk, you will want to let your pulse speed up,
assuming your doctor has not identified any reason not to do so. Your pulse should be higher than at rest and should be around your target zone. It should never be so fast that you cannot speak, have trouble breathing, or have any chest discomfort.

After a few minutes, check your pulse at your wrist or (gently) at your carotid artery, just to the side of your windpipe. Count the number of beats in fifteen seconds, and multiply by four to get the beats per minute.

Remember, you do not need to peg your workout to any certain distance. Rather, just aim to keep your heartbeat in your target zone for a period of time, as I described above. That means you can run, walk, or stop as much as you need to. The goal is to keep your pulse in the right zone. Before long you will find that you can sense whether your pulse is in the zone without actually checking it manually.

There are three keys to a successful exercise program:

Make it social.
Some people go for the “no pain, no gain” mind-set and sign up for a boot camp experience where they get up at 5:30 in the morning to be yelled at by a former drill sergeant. But you are not one of them. Really, you won’t stick with something unless you honestly enjoy it.

What turns physical activity into genuine fun is companionship. Go for a walk with a friend or family member. Pick a place you enjoy, whether that means natural surroundings, a busy urban avenue, or whatever your tastes call for.

If you join a gym, join with a friend if you can. And sign up for classes where you’ll meet other people. We are much more likely to stick with an exercise plan if it’s fun and if our companions are expecting us!

So take a minute now and think about how this can work for you. Who can you bring into your exercise routine? Where can you go to be with other people who are quickening their pulses, too?

By the way, exercise does not have to mean treadmills and weight lifting. It also means dancing, tennis, and a walk in the park. You can hold hands while you walk (particularly if you know each other).

Schedule it.
To make it work, put it on your schedule—actually write it down. Things that get scheduled get done; things that are left to chance get neglected. Plan out your exercise program for the next three weeks, and treat it like a doctor’s appointment or any other appointment you would be loath to miss.

So take a minute now and schedule it. Yes, actually jot it down on your calendar, and when exercise time comes up, off you go!

Keep it regular.
Once you’re in an exercise groove, it’s easy to stay there. But if your exercise is only intermittent, your motivation really never gets off the couch. So keep it regular. If you set a rule that you’re going for a brisk walk every day after dinner, or whatever schedule works for you, you’ll find that you come to expect it and enjoy it. Don’t let yourself have more than two sedentary days in a row.

Exercise is like an antibiotic. A single dose doesn’t help very much. But if you take it on schedule, it’s exactly the cure you’re looking for.

So keep it social, put it on your schedule, and keep it regular, and everything else will fall into place.

Go for variety. You might try a combination of walking and running. Or if you’re feeling more energetic, go for bicycling, play tennis, go dancing, or whatever is your pleasure.

Don’t disparage golf. Some people think of the sport as Mark Twain did—“a good walk ruined.” I can’t say I blame them. But if you can handle the humiliations of this challenging sport, you’ll get a good walk in. Avoid the carts and especially avoid the foods served in the clubhouse.

Some people like exercise videos. They allow you to get hot and sweaty in the comfort of your own home. You’ll find plenty of them online and at libraries.

You might like to use a pedometer. It’s a little device clipped to your belt that tracks your steps. For some people, it brings in a bit of competitiveness in a good way. If they walked five thousand steps yesterday, they are going for seven thousand today. In our research studies, we use an Omron brand, but there are many others on the market. You can program in the length of your stride to track your mileage and how many calories you’ve burned. To give you a frame of reference, a vigorous day for a healthy, fit person would add up to about 10,000 steps. But stay within your own limits.

Whatever you do, don’t let guilt invade your exercise life. Sometimes people scold themselves if they have not found the time to exercise. But it’s really just a question of biology: Physical activity is good for us, and you can start when you’re ready. And if you’ve drifted away from an exercise program, don’t worry. It happens to everyone. Just dust yourself off and get back on when you can. Have fun with it.

You’ll want to tailor your exercise plan to your goals, thinking about the three different kinds of exercise, each of which has its own benefits:

Aerobic exercise
means running, brisk walking, bicycling, an organized step-aerobic class, tennis, dancing, or any other continuous activity that gets your heart pumping. That’s what we’ve focused on so far because, for brain protection, aerobic exercise is what really counts. This is the kind of exercise that boosts brain size and has been shown to noticeably improve working memory, planning, multitasking, and other cognitive functions.
¹²
It also improves your cardiac fitness, lowers your blood sugar and triglycerides, and reduces cancer risk. But there are two more kinds of exercise that will round out your benefits.

Resistance exercise
builds muscular strength. Weight lifting, push-ups, and deep knee bends strengthen your skeleton, too. If your bone strength has been weakened by osteopenia or osteoporosis, working your muscles will, in turn, gradually strengthen your bones.

A typical regimen for resistance training works all major muscle groups three times a week. The workout would include three sets of eight to ten repetitions at a weight that cannot be lifted more than eight to ten times.

Flexibility exercises
improve your joint range of motion, keep you limber, and help eliminate chronic pain. Yoga and Pilates are two excellent forms of flexibility exercises.

For resistance and flexibility training, I highly recommend having at least one session with a personal trainer. Everyone’s needs and vulnerabilities differ so much that it really pays to have someone design a program that fits you.

Ever wonder why some people just love to exercise, while others find it daunting? It’s not a question of character. It’s biology.

Some people are born with muscles that have a great many “type I” cells—special muscle cells that have a rich supply of capillaries to bring in oxygen, remove waste products, and prevent fatigue. These cells also have a large quantity of an enzyme called lipoprotein lipase, which breaks fats apart to be used as fuel. If your muscles are loaded with type I cells, you’ll feel like running long after your friends have collapsed from exhaustion.

Type II cells are different. They are fine for a short sprint, but they run out of gas before you’ve gone very far.

So when people love exercise or loathe it, it’s mostly a question of biology—the kind of muscle cells they were born with.

But here’s what counts:
You can change the makeup of your muscles
. With vigorous exercise, type II cells start to get a better and better blood supply, eventually making them very much like type I cells.

Exercise aptitude is largely genetic, but exercise itself can compensate for what nature might have forgotten.

So exercise counters brain shrinking and helps everything work better. It also has some important “side effects.” First, the physical ones:

• Exercise helps you lose weight. It adds to your overall calorie burn, and is also calorie-free. You just can’t dip shrimp into tartar sauce while you’re playing tennis, and it’s hard to scarf down a burger on your bicycle.
  
• For your heart, exercise improves cardiac fitness, reduces blood pressure, boosts HDL (“good”) cholesterol, and trims triglycerides.
  
• Women who exercise have less risk of developing breast cancer and better survival if cancer strikes.
  

There are some big psychological benefits, too:

• Physical activity helps you sleep better. It’s not hard to see why: As your muscles become tired, they demand sleep. And when you’ve slept well, you feel like sticking to a
  healthier lifestyle. Moreover, sleep might even help you prevent Alzheimer’s disease, as we will see in the next chapter.
  
• Exercise is a natural antidepressant. In some studies, it is about as effective as antidepressant medications.
  

Let me repeat a key point:
It is essential to exercise along with a healthy diet, not in place of it.
So many people imagine that because they have exercised, they can dig into unhealthy foods. But exercise cannot “burn off” cholesterol, and it is a lot to ask for exercise to undo the effects of a bad diet.

Think of physical exercise as an important tool in your toolbox. Start with a healthy diet, add mental and physical exercises, and you’re taking real power into your hands.

B
y now you’ve learned a great deal about how nutrients protect your brain and how exercises—physical and mental—strengthen your neural connections and reverse age-related brain shrinkage. But, as important as they are, these steps can be defeated if you do not avert certain common memory threats.

Sleep is when memories are consolidated, like files being neatly stored in a filing cabinet. If your sleep is disturbed, your memory “files” remain in a jumble, and you’ll have trouble coming up with names and words you need.

In addition, certain medications and health conditions can wreak havoc with your brain cells. Many people have no idea that their memory problems can be solved simply by changing a prescription or correcting an underlying medical condition.