Middle aged people who regularly exercise and are physically fit have a much lower risk of developing chronic health conditions associated with old age, researchers from the Cooper Institute, Dallas, USA reported in Archives of Internal Medicine. The authors added that even a moderate increase in fitness during midlife can help reduce the risk of developing several chronic conditions twenty years later.

Several studies have looked into how physical fitness might impact on elderly health and longevity. A report published in the British Journal of Sports Medicine in 2008 showed that midlife aerobic fitness can delay biological aging by up to 12 years, as well as securing an independent lifestyle during old age.

Dr. Benjamin L. Willis and team gathered data from Medicare claims with information on participants from the Cooper Center Longitudinal Study, involving 14,726 men and 3,944 women. The data spanned from 1970 to 2008. All the participants were healthy and had an overall median age of 49 years at baseline.

The researchers were looking out for incidence of eight chronic conditions after the age of 65: Alzheimer’s disease, colon or lung cancers, chronic kidney disease, COPD (chronic obstructive pulmonary disease), stroke, ischemic heart disease, diabetes, and congestive heart failure.

The authors wrote:

“In the present study, higher fitness measured in midlife was strongly associated with a lower incidence of CCs decades later.”

The participants were followed up on average for 26 years. Those in the top quintile for fitness had a considerably lower incidence of chronic conditions later in life compared to the people in the bottom quintile (1.5 vs 28.2 per 100 person years in males, and 11.4 vs. 20.1 in females). Participants’ fitness levels were measured by getting them to do certain tasks on a treadmill.

The authors wrote:

“For example, a 1- to 2-MET [metabolic equivalent] improvement in fitness resulting in promotion from the first to the second fitness quintile at age 50 years was associated with a 20 percent reduction in the incidence of CCs at ages 65 and older.”

Midlife fitness appears to be more closely linked with a lower incidence of chronic diseases later on than improved survival, which also benefits, but less so, the researchers noted. Dr. Willis explained that “Compared with participants with lower midlife fitness, those with higher midlife fitness appeared to spend a greater proportion of their final five years of life with a lower burden of chronic conditions.”

In other words, midlife fitness increases your chances of living more healthily during old age and having a lower risk of developing chronic conditions. Your lifespan may benefit slightly too. Your last years of life are more likely to be free of chronic diseases, or at least affected by fewer of them, compared to unfit middle-aged people.

Dr. Diane Bild, of the National Heart, Lung and Blood Institute, Bethesda, Md., said that Dr. Willis and team have provided further compelling evidence about the importance of physical fitness during middle age as a contributor to better health later on in life.

Dr. Bild added:

“Fitness may be a key to healthy aging, but the interpretation and translation of the findings of this article require some caution. …Yet, fitness is a function of both exercise and genetics. Because genetics likely plays a role in longevity and certainly plays a role in disease avoidance, if some of the same genes are involved in longevity and fitness, they may serve as major confounders in the attractive interpretation that exercise leads to fitness, which leads to healthy aging.

“Research on healthy aging is important for its insights into living longer, healthier and more active lives and, potentially, reducing health care costs. In addition to observational studies such as the present one, clinical trials are needed to establish definitively the benefits and risks of approaches that have been shown in observational studies to be associated with extending health and life.”

Researchers from the University of Kansas School of Medicine in Kansas City, in 2009 found that even when somebody has a chronic disease, such as Alzheimer’s, fitness (cardiorespiratory fitness) has been shown to reduce brain atrophy in patients in the early stages of the disease.

Being physically fit during midlife is becoming more scarce. Researchers fom the University of Houston, Texas, published a study in Archives of Internal Medicine in 2009 which showed that we all gradually become less fit as we age, with declines speeding up after 45. They added that the US population is aging, but becoming more sedentary and obese at the same time. Unless fitness levels of middle-aged and elderly Americans improve, the incidence of chronic diseases among seniors will rise considerably.

Written by Christian Nordqvist