by Howard Lewine, M.D.
What would you pay to keep from getting sick as you get older? How about a daily walk or other exercise? A new study suggests that’s exactly the right investment. In the study, people who were the most fit at midlife lived longer and spent less time being sick than middle-aged folks who weren’t fit.
There are many benefits to staying physically active and exercising daily. Exercise strengthens the heart and lungs; makes blood vessels more flexible and responsive, improving circulation; controls blood pressure and cholesterol; helps muscles burn sugar; reduces stress; decreases the risk of diabetes, heart disease, some cancers and other chronic conditions; preserves memory and prolongs life.
Another important effect of exercise, one that doesn’t get enough attention, is that it improves fitness. Fitness is a measure of how well your heart, blood vessels, blood and lungs work together to supply muscles with oxygen during sustained exercise. It also estimates how efficiently the muscles use the oxygen. Fitness also reflects your exercise capacity.
The most accurate fitness gauge requires complicated machinery and sensors to measure the maximum oxygen consumed during exercise. This is called VO2max. It can also be done using the kind of treadmill test that cardiologists commonly use to check for heart disease.
Fitness translates to better health later on
To explore the effect of fitness on health status in old age, researchers with the Cooper Institute in Dallas, Texas, looked at information that had been gathered from more than 18,600 men and women who were part of another long-term health study. When the study began, their median age was 49. Fitness levels were measured using a type of treadmill test. Once a volunteer reached age 65, the researchers tracked his or her health with Medicare claims information.
Those who were the most fit at midlife were less likely over the course of the 26-year study to have died of coronary artery disease, Alzheimer’s, heart failure, diabetes and other chronic conditions, the researchers reported in Archives of Internal Medicine. Just over 2,400 people died during the study. In the last five years of their lives, the people who’d been most fit at midlife spent about 50 percent less time with four or more chronic diseases than the least fit group and 34 percent more time with no or one chronic disease.
Find your fitness
How do you improve your fitness? Increase the amount and the intensity of exercise over time.
Exercise capacity is usually measured in metabolic equivalents (METs). One MET is the amount of oxygen used when sitting still or sleeping. Nonathletic, healthy, middle-aged men and women have peak exercise capacities in the range of 8 to 10 METs. Marathon runners can have values as high as 18 to 24.
But you don’t need an expensive exercise stress test to determine your fitness. Many fitness centers have exercise machines that show METs. Some home treadmills and elliptical trainers also show METs.
If you don’t have access to such a machine, or don’t like exercising on one, you can measure your current fitness with a simple walking test. All it takes is a one-mile track or level terrain that you know is one mile long. You’ll also need a stopwatch or watch with a second hand, paper, and a pen or pencil.
First, get yourself warmed up by walking briskly for a few minutes. Record the time and start walking as fast as you can. Push yourself, but don’t overdo it. When you cross the one-mile mark, record the time again. Calculate how many minutes it took to finish the mile. Don’t be concerned about how low your METs are now or how slow you walked. What’s important is to improve them. You can do this with regular exercise that challenges your body. That means working hard enough to speed up your heartbeat and breathing.
The intensity of exercise and the amount of time spent exercising that are needed to improve fitness differ from person to person. The goal is to increase your METs or decrease the number of minutes it takes you walk one mile. Don’t rush it. Improving fitness starts within weeks but will continue for months.
Howard Lewine M.D., is Chief Medical Editor, Internet Publishing, Harvard Health Publications.