UF researchers: Few adults are reaching recommended intensity during physical activity

August 22, 2001

GAINESVILLE, Fla. --- Many physically unfit adults think they exercise more vigorously than they do, a misperception that may hamper their efforts to prevent heart disease, University of Florida researchers report.

The researchers agree that any physical activity is better than none, but those who exercise at the moderate and high intensity levels see the greatest benefits. Activity levels of 66 sedentary adult men and women were evaluated for one week to assess the frequency, intensity and duration of their physical activities.

Researchers found that study participants accurately reported the amount of daily exercise, but most did not accurately report level of intensity. The researchers hope the findings will lead to a re-evaluation and clarification of traditional exercise protocols that recommend intensity levels.

"There is a clear relationship between the amount of physical activity a person engages in and the risk for heart disease," said Glen E. Duncan, principal investigator of the study published in the July issue of Preventive Medicine. "Most of the sedentary adult population cannot achieve the recommended intensity level of activity." Duncan is a postdoctoral associate in UF's College of Medicine.

Approximately 960,000 Americans die from cardiovascular disease every year, with 250,000 of those deaths attributed to a lack of regular physical activity.

Surveys show that a quarter of Americans do not participate in any physical activity and of those who do, only 46 percent do it regularly and intensely enough to protect their hearts.

The American Heart Association provides specific guidelines for exercise aimed at lowering the risk of heart disease and heart attack, high blood pressure, high cholesterol, obesity and diabetes. Physical benefits also include strengthening of muscles and bones, boosting energy and improving weight control.

The research was conducted as part of UF's ongoing "walking project," sponsored by the National Heart, Lung and Blood Institute and led by clinical and health psychologist Michael G. Perri, a professor in UF's College of Health Professions. Researchers hope to answer the questions of how often and how hard people should exercise to receive the greatest cardiovascular benefits. The four-year study began in fall 1998.

"Seventy-five percent of all Americans are either sedentary or getting less physical activity than seen as appropriate for good health," said Perri, co-principal investigator of the study.

The study participants, volunteers from Gainesville, Fla., and surrounding communities, were adults who had been exercising moderately for less than an hour each week. To make sure the volunteers were able to engage safely in vigorous exercise activities, physical examinations and stress tests were conducted before admittance to the study. Participants were interviewed to recall the amount and level of their daily activity for the previous week. That information was compared with measurements recorded by heart rate monitors and activity logs completed by the participants.

In their activity logs, 47 percent of the volunteers wrote that they participated in moderate activity for at least 10 minutes, but the heart rate monitors showed that only 15 percent reached moderate intensity. While 11 percent reported exercising at the hard intensity level, heart rate monitors revealed that fewer than 2 percent reached that level.

"The results reveal that we must use caution in interpreting what sedentary adults tell us about their exercise habits, since they commonly overestimate the intensity of moderate activity," said Paul M. Ribisl, chairman of the department of health and exercise science at Wake Forest University.

"This could possibly give us misleading information about health benefits from such activity when using self-report data. Health-care professionals need simple methods to track these behaviors if they are to determine effective strategies."

Research suggests that in order to better protect themselves from heart disease, people should maintain a moderate to hard intensity level of activity that increases their metabolism to six times their energy consumption during rest. The exercise should be done three to four times a week for 30 minutes to one hour. Moderate intensity is equivalent to a brisk walk. Hard intensity is defined as a level equivalent to jogging.

"The problem that we found is, for both moderate and hard levels, sedentary people are not accurate in judging how intensely they are exercising," Perri said. In light of these findings, Duncan suggests adults need better guidance when defining their level of activity.
-end-


University of Florida

Related Heart Disease Articles from Brightsurf:

Cellular pathway of genetic heart disease similar to neurodegenerative disease
Research on a genetic heart disease has uncovered a new and unexpected mechanism for heart failure.

Mechanism linking gum disease to heart disease, other inflammatory conditions discovered
The link between periodontal (gum) disease and other inflammatory conditions such as heart disease and diabetes has long been established, but the mechanism behind that association has, until now, remained a mystery.

New 'atlas' of human heart cells first step toward precision treatments for heart disease
Scientists have for the first time documented all of the different cell types and genes expressed in the healthy human heart, in research published in the journal Nature.

With a heavy heart: How men and women develop heart disease differently
A new study by researchers from McGill University has uncovered that minerals causing aortic heart valve blockage in men and women are different, a discovery that could change how heart disease is diagnosed and treated.

Heart-healthy diets are naturally low in dietary cholesterol and can help to reduce the risk of heart disease and stroke
Eating a heart-healthy dietary pattern rich in vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, vegetable oils and nuts, which is also limits salt, red and processed meats, refined-carbohydrates and added sugars, is relatively low in dietary cholesterol and supports healthy levels of artery-clogging LDL cholesterol.

Pacemakers can improve heart function in patients with chemotherapy-induced heart disease
Research has shown that treating chemotherapy-induced cardiomyopathy with commercially available cardiac resynchronization therapy (CRT) delivered through a surgically implanted defibrillator or pacemaker can significantly improve patient outcomes.

Arsenic in drinking water may change heart structure raising risk of heart disease
Drinking water that is contaminated with arsenic may lead to thickening of the heart's main pumping chamber in young adults, according to a new study by researchers at Columbia University Mailman School of Public Health.

New health calculator can help predict heart disease risk, estimate heart age
A new online health calculator can help people determine their risk of heart disease, as well as their heart age, accounting for sociodemographic factors such as ethnicity, sense of belonging and education, as well as health status and lifestyle behaviors.

Wide variation in rate of death between VA hospitals for patients with heart disease, heart failure
Death rates for veterans with ischemic heart disease and chronic heart failure varied widely across the Veterans Affairs (VA) health care system from 2010 to 2014, which could suggest differences in the quality of cardiovascular health care provided by VA medical centers.

Heart failure: The Alzheimer's disease of the heart?
Similar to how protein clumps build up in the brain in people with some neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, protein clumps appear to accumulate in the diseased hearts of mice and people with heart failure, according to a team led by Johns Hopkins University researchers.

Read More: Heart Disease News and Heart Disease Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.