On Nutrition by Ed Blonz

STAYING -- OR BECOMING -- ACTIVE LATER IN LIFE

DEAR DR. BLONZ: I have been active most of my life and have always eaten well. As time has passed, my abilities have decreased (as expected), and now that I have just turned 70, I am wondering whether there need to be changes in what I eat and drink. My partner and I take a fitness class that is promoted to improve flexibility, balance and strength. -- O.M., Chicago

DEAR O.M.: Nutritional requirements for active older people are not much different from those who are sedentary, with two exceptions: water and calories. Both require a varied diet that focuses on nutrient-dense fruits, vegetables, grains, nuts, seeds and dairy products, along with high-protein foods such as fish, poultry and meats. As an active person, you will simply require more total calories than a sedentary peer.

Our metabolisms go through changes as we progress through midlife to our senior years. Most of us become less active, and muscle mass shrinks following the dictates of the body's "use it or lose it" mandate. Smaller, less active muscles require fewer calories; think of the analogy of the gas used by an eight-cylinder versus a four-cylinder engine.

Over time, some aspects of the digestive system become less efficient, and our ability to sense thirst diminishes, which can result in dehydration. Mineral loss in our bones can begin to become apparent at about age 40. We tend to get a bit shorter (although most tend to think their height is the same as it was in their youth), and this means an increased risk of osteoporosis. There is less range of motion in the joints due, in part, to fewer demands on the way we move. This is the script for a sedentary lifestyle, but more active types, especially those who include flexibility and movement exercises, will experience fewer of these negatives.

Though you say you have long been active, I would like to spend some time addressing any readers who want to start becoming more active in their later years.

First of all, start slowly. Touching base with your health professional makes sense if there are any health issues. While muscles don't respond as they did in your youth, you will slowly adapt to your new routines. I encourage all to consult with credentialed trainers who can map out a reasonable course. An important benefit is that muscular work helps you hold on to your bone strength, and as long as you go slowly and don't overdo it, the joints will regain and retain more flexibility to help support the physical activity. This will also help improve your balance. The circulatory system also improves, providing fuel and removing waste materials from the working muscles. You may also find improvements in your sleep habits.

A word on water: Drink some before, during and after exercise because it helps keep the body cool through perspiration. In addition, water facilitates the shuttling of waste products from energy production out of the body through the urine. Dehydration, even when mild, impairs performance and can cause the body to overheat and malfunction. This can be especially dangerous in the older athlete, because the kidneys do not operate as efficiently. Because one's awareness of thirst can be lost during exercise, it's best to make drinking water a part of any exercise routine.

You might want to take a complete set of body measurements before you start. Finding that your clothes begin to fit differently is great feedback. Hunger may increase, but try to focus on fruits, vegetables and other nutrient-dense foods, all eaten slowly. Keep track of your weight weekly, but be less concerned with the numbers than with the knowledge that you are doing things for yourself that nobody else can do.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.