Dear Doctor: Can you give me some ideas on how to lose weight while using a wheelchair? I'm 66 and need a wheelchair to get around. When the distance is short enough, I use crutches. I'm on a tight budget, but try to work out as much as I can, with very little results. I'm getting depressed because nothing seems to work.

Dear Reader: One look at the multibillion-dollar weight-loss industry, and it's clear that staying fit is difficult for many of us. And while limited mobility certainly adds to the challenge, with creativity and determination, you can win this battle.

When you use a wheelchair, it's particularly important to get fit and to maintain a healthy weight. Even a few excess pounds can make it more difficult to get into and out of a wheelchair. In that same vein, you need your shoulders, arms and abs to remain strong so you can easily move into and out of the chair, and to prevent injury as you do so.

Let's start with what you eat. Focus on a diet made up of a variety of fresh fruits and vegetables, lean proteins, dairy products, healthy fats, legumes, whole grains and leafy greens. Limit added sugars, and cut out empty calories like sodas and processed snack foods. The key here is to adjust your diet to your level of physical activity.

One tool that really works (and takes a bit of courage to do honestly) is keeping a food diary. Even if just for one week, write down everything that passes your lips. The details will jolt you into awareness and, quite possibly, motivate you to make some changes.

As for exercise, the days of the sedentary wheelchair-user are over. There are several exercises you can do from your chair.

With a pair of hand weights, you can keep your biceps, triceps, pectorals and even your abs strong and toned. Resistance bands are another way to maintain strength and range of motion.

An exercise ball is an excellent workout tool. Hold it above your head and, as you engage your stomach muscles, slowly rotate from left to right and back again. Lift the ball above your head and slowly lower it, again engaging your abdominals. Hold the ball above your head, once again engaging your abs, and perform slight tilts to the points of the compass.

With all of these, the idea is to start slow and gradually build up repetitions. Stop if you feel any pain. And be sure to drink water and stay hydrated.

Is there a senior citizen center in your area? Many of them have exercise and yoga classes that can be adapted for someone using a wheelchair. Some even have sports teams that will make room for a rolling athlete.

A challenge for all of us as we get older is social isolation. A group activity can help you feel connected, which will raise your spirits and keep you motivated.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Which pain reliever is safer -- acetaminophen, ibuprofen, celecoxib or naproxen? It seems as if they all carry some risks.

Dear Reader: Pain is a symptom to which we can all relate. It's also an important indicator of possible injury within the body and should be acknowledged, not simply by taking medication, but also by understanding the cause of the pain. That said, one person's pain is different than another's, with some people needing greater pain relief.

So, if you need a medication for pain, what should you use? Let's look first at acetaminophen (Tylenol). Acetaminophen has been used since 1955; it is available in multiple products, works well for pain, and is for the most part safe. However, at high doses -- specifically, above 4,000 milligrams a day, or eight tablets of Extra Strength Tylenol -- the medication can cause liver damage, or even death, especially in those who are malnourished, drink alcohol in excess or consistently take more than 4,000 mg per day. Age is also a factor, as those over 40 have a greater risk of liver failure and death after over-dosage.

Ibuprofen (Advil, Motrin) has been used for pain since 1974. It is one of many medications classified as non-steroidal anti-inflammatory drugs (NSAID). NSAIDs work by inhibiting formation of mediators of pain and inflammation, and they're notably effective at decreasing inflammation in swollen joints related to arthritis.

Naproxen (Aleve) was first marketed in 1976 and works similarly to ibuprofen. But it has a longer half-life, giving it a longer-lasting effect. Both ibuprofen and naproxen decrease the formation of prostaglandins in the stomach. These chemicals produced by the body have hormonelike effects, protecting the stomach lining from acidity. The decrease of prostaglandins can injure the stomach lining, leading to stomach inflammation, ulcers and possibly severe bleeding.

Celecoxib (Celebrex) is a more selective NSAID and does not decrease prostaglandins in the stomach. This translates into significantly less likelihood of creating ulcerations.

All NSAIDs also reduce prostaglandins in the kidneys, which can lead to kidney injury. This injury becomes worse in people who have a history of chronic kidney disease, who are older, or who have congestive heart failure or cirrhosis.

Lastly, the chronic use of high-dose NSAIDs has been linked to an increased risk of heart attacks. Celecoxib may have a slightly greater risk of this than ibuprofen and naproxen, but a recent New England Journal of Medicine study looking at those who used NSAIDs chronically for arthritis found no difference in cardiovascular events between celecoxib and either ibuprofen or naproxen.

Of the drugs you listed, my feeling is that acetaminophen is the safest when used regularly. However, I would use acetaminophen at no higher doses than 4,000 mg per day and, if you were to use it regularly, I would recommend decreasing this amount to 2,000 to 3,000 mg per day.

The NSAIDs -- ibuprofen, naproxen and celecoxib -- are needed by some who have inflammatory arthritis, and they are good medications in the short-term. I would caution against consistent long-term use, especially at high doses and especially if you have any history of heart disease.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My memory is terrible. To be honest, it always has been. I seem to spend half my time searching for my keys or wondering whether I forgot to turn off the stove and lights. Could memory training help?

Dear Reader: Ready for a short answer that you're not likely to forget?

Yes.

As long as problems with recall do not arise from either medical or physiological issues, it is indeed possible to improve one's memory. And it's not just a matter of mastering complex systems or relying on clever tricks. An intriguing study published in the scientific journal Neuron shows that a certain type of memory training has a measurable and lasting effect on networks that connect different regions of our brains.

Researchers compared the brain activity of 23 top memory athletes with 23 people with no memory training at all. After just six weeks of training, scans of the brains of the amateurs began to resemble those of the memory athletes.

The training focused on a strategy known as "method of loci," also sometimes called the memory palace. The idea is that you mentally "place" things you want to remember -- a person's name, where you put the phone bill, what your spouse asked you to pick up at the store -- into a landscape you know really well. Then when you picture yourself moving through that landscape, you'll encounter the items you wanted to remember.

What was striking about the study wasn't just that the amateurs significantly improved their memories. In the months after learning and adopting the method of loci technique, the new pathways created in their brains were still there.

That's all pretty high-octane stuff. But science shows that maintaining a good memory is a whole-body endeavor, and that simple lifestyle changes can make a difference.

Here at UCLA, we have a memory program for adults with known risk factors for cognitive decline. These risk factors include being sedentary, being overweight, having diabetes or having a family history of Alzheimer's or dementia. Studies show that stress and depression can also have a hand in memory issues.

Participants in the UCLA program improve their diets and are asked to exercise regularly and work on stress reduction. They also do brain training, some of it quite similar to the regimens reported in the Neuron study. They make a point of memorizing the kind of information that we now relegate to our electronic devices, such as a shopping list, frequently called phone numbers, birthdays of family and friends, addresses, and one or two credit card numbers.

At the end of 12 weeks, participants reported improvements not only to their memories, but also to their moods and general sense of well-being. They enjoyed the challenges of shopping without a list and skipping the autodial feature on their phones to make calls themselves.

Perhaps a similar memory program is available in your area. And even if not, an improved diet, more exercise and basic memory practice are changes that you can incorporate into your own life.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)