By analyzing reported physical activity levels over time in more than 11,000 American adults, Johns Hopkins Medicine researchers conclude that increasing physical activity to recommended levels over as few as six years in middle age is associated with a significantly decreased risk of heart failure. This condition affects an estimated five million to six million Americans. The same analysis found that as little as six years without physical activity in middle age was linked to an increased risk of the disorder.
Unlike heart attack, in which heart muscle dies, heart failure is marked by a long-term, chronic inability of the heart to pump enough blood, or pump it hard enough, to bring needed oxygen to the body. The leading cause of hospitalizations in those over 65, the disorders risk factors include high blood pressure, high cholesterol, diabetes, smoking and a family history.
In everyday terms our findings suggest that consistently participating in the recommended 150 minutes of moderate to vigorous activity each week, such as brisk walking or biking, in middle age may be enough to reduce your heart failure risk by 31 percent, saysChiadi Ndumele, M.D., M.H.S.,the Robert E. Meyerhoff Assistant Professor of Medicine at the Johns Hopkins University School of Medicine, and the senior author of a report on the study. Additionally, going from no exercise to recommended activity levels over six years in middle age may reduce heart failure risk by 23 percent.
The researchers caution that their study, described in the journalCirculation, was observational, meaning the results cant and dont show a direct cause-and-effect link between exercise and heart failure. They say the trends observed in data gathered on middle-aged adults suggest that it may never be too late to reduce the risk of heart failure with moderate exercise.
Strategies For Prevention
The population of people with heart failure is growing because people are living longer and surviving heart attacks and other forms of heart disease, says Roberta Florido, M.D., cardiology fellow at the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease. Unlike other heart disease risk factors like high blood pressure or high cholesterol, we dont have specifically effective drugs to prevent heart failure, so we need to identify and verify effective strategies for prevention and emphasize these to the public. There are drugs used to treat heart failure, such as beta blockers and ACE inhibitors, but they are essentially secondary prevention drugs, working to reduce the hearts workload after dysfunction is already there.
Several studies suggest that in general people who are more physically active have lower risks of heart failure than those who are less active, but little was known about the impact of changes in exercise levels over time on heart failure risk. For example, if you are sedentary most of your life but then start exercising in middle age, does that decrease your risk of heart failure? Or, if you are active much of your life but then stop being active at middle age, will that increase your risk?
To address those questions, the researchers used data already gathered from 11,351 participants in the federally-funded, long-term Atherosclerosis Risk in Communities (ARIC) study, recruited from 1987 to 1989 in Forsyth County, North Carolina; Jackson, Mississippi; greater Minneapolis, Minnesota; and Washington County, Maryland. The participants average age was 60. Fifty-seven percent were women and most were either white or African-American. Participants were monitored annually for an average of 19 years for cardiovascular disease events such as heart attack, stroke and heart failure using telephone interviews, hospital records and death certificates. Over the course of the study there were 1,693 hospitalizations and 57 deaths due to heart failure.
In addition to those measures, at the first and third ARIC study visits - six years apart - each participant filled out a questionnaire, which asked them to evaluate their physical activity levels, which were then categorized as poor, intermediate or recommended, in alignment with guidelines issued by the American Heart Association. The recommended amount is at least 75 minutes per week of vigorous intensity or at least 150 minutes per week of moderate intensity exercise. One to 74 minutes per week of vigorous intensity or one to 149 minutes per week of moderate exercise per week counted as intermediate level activity. And physical activity qualified as poor if there was no exercise at all.
After the third visit, 42 percent of participants - 4,733 people - said they performed recommended levels of exercise; 23 percent - 2,594 people - said they performed intermediate levels; and 35 percent - 4,024 people - said they had poor levels of activity. From the first to the third visit over about six years, 24 percent of participants increased their physical activity, 22 percent decreased it and 54 percent stayed in the same category. Those with recommended activity levels at both the first and third visits showed the highest associated heart failure risk decrease - at 31 percent - compared with those with consistently poor activity levels.
Reducing Heart Failure Risk
Heart failure risk decreased by about 12 percent in the 2,702 participants who increased their physical activity category from poor to intermediate or recommended, or from intermediate to recommended, compared with those with consistently poor or intermediate activity ratings. Conversely, heart failure risk increased by 18 percent in the 2,530 participants who reported decreased physical activity from visit one to visit three, compared with those with consistently recommended or intermediate activity levels.
The researchers determined how much of an increase in exercise, among those initially doing no exercise, was needed to reduce the risk of future heart failure. Exercise was calculated as METs (metabolic equivalents), where one MET is 1 kilocalorie per kilogram per hour. Essentially, sitting watching television is 1 MET, fast walking is 3 METs, jogging is 7 METs and jumping rope is 10 METs. The researchers calculated outcomes in METs times the number of minutes of exercise. The researchers found that each 750 MET minutes per week increase in exercise over six years reduced heart failure risk by 16 percent. And each 1,000 MET minutes per week increase in exercise was linked to a reduction in heart failure risk by 21 percent.
Benefits Of Physical Activity Vs. Impact Of Obesity
The benefits of physical activity may outweigh the impact of overweight and obesity on cardiovascular disease in middle-aged and elderly people, according to research published in theEuropean Journal of Preventive Cardiology. The observational study was conducted in more than 5,000 people aged 55 years and older who were followed-up for 15 years. "Obesity is associated with a higher risk of cardiovascular disease and it is recommended to lose weight," said author Dr. Klodian Dhana, a postdoctoral researcher in the Department of Epidemiology, Erasmus University Medical Centre, Rotterdam, the Netherlands. "But in the elderly this is slightly different because weight loss, especially unintentional, is associated with muscle loss and death. Physical activity is associated with a lower risk of cardiovascular disease regardless of age. We investigated the combined impact of body mass index (BMI) and physical activity on cardiovascular disease in the middle age to elderly population."
The study included 5,344 individuals aged 55 to 97 years of age - average 70 years - who participated in the Rotterdam Study and were free of cardiovascular disease at baseline. Information about BMI, physical activity, smoking, alcohol use, diet, education, and family history of premature heart attack was collected during the enrollment period from 1997 to 2001. Participants were categorized by BMI: normal weight, overweight, and obese; and physical activity, which was below and above the median in the study population. The group was followed from 1997 to 2012 for cardiovascular events - heart attack and stroke.
During the 15-year follow-up, 16% of participants had a cardiovascular event. When analyzed alone, physical activity was associated with a decreased risk of cardiovascular disease regardless of BMI category. There was no association between BMI alone and cardiovascular disease. "In the overall population we found that physical activity was protective for cardiovascular risk," Dhana said. "Overweight and obese participants were not at increased cardiovascular risk compared to those of normal weight. We do not refute the risk associated with obesity in the general population even though we did not find it in this older group. BMI may not be the best way to measure adiposity risk in the elderly."
The Impact Of BMI
The researchers analyzed the joint effect of physical activity and BMI. Compared to normal weight people with high physical activity levels, overweight or obese individuals with high levels of physical activity were not at increased risk of cardiovascular disease, but overweight or obese people with low levels of physical activity had 1.33 and 1.35 times higher risk for developing cardiovascular disease, respectively. "Our results show that physical activity plays a crucial role in the health of middle age to elderly people," Dhana said. "Those who are overweight and obese without adequate physical activity are at higher risk of developing cardiovascular disease."
Those overweight or obese exert harmful effects through adipose tissue which accelerates the atherosclerotic process and increases cardiovascular risk. Physical activity lowers the harmful effects of atherosclerosis by reducing the stabilization of plaques on blood vessels and reducing the heart's oxygen demand. "People who engage in high levels of physical activity are protected from the harmful effects of adipose tissue on cardiovascular disease," Dhana said. "This may be why we found that the beneficial impact of physical activity on cardiovascular disease outweighs the negative impact of BMI."
The Rotterdam Study was an active population, with the low and high groups doing two and four hours of daily activity. This included biking, walking and housework. The important point was that the study compared the two groups and found that more activity was better for health. "Any physical activity is positive for cardiovascular health and in elderly people of all weights walking, biking and housework are good ways to keep moving," Dhana added. "European guidelines recommend 150 minutes a week of moderate intensity physical activity to decrease the risk of cardiovascular disease."
Mindful Motivation To Move
A meditation and stress reduction program may be as effective at getting people to move more as structured exercise programs, according to a new study led by an Iowa State University researcher. The study compared two intervention programs mindfulness-based stress reduction and aerobic exercise training with a control group and measured changes in exercise, general physical activity and sedentary time. People assigned to the two interventions were more active than those in the control group, logging roughly an extra 75 minutes a week of moderate-to-vigorous physical activity following the eight-week interventions. Theresultsare published in the journalMedicine & Science in Sports & Exercise.
Jacob Meyer, an ISU assistant professor ofkinesiology, and his colleagues at the University of Wisconsin-Madison and University of Mississippi Medical Center, say helping sedentary adults get those 75 minutes of exercise can extend life expectancy by nearly two years. Researchers expected the exercise intervention to increase physical activity more than the meditation training. Meyer says to see similar results from the mindfulness intervention was somewhat surprising. Structured exercise training is something as a field we have used for decades to improve physical activity and physical health, Meyer said. To see a similar effect on physical activity from an intervention that focuses on the way someone thinks or perceives the world, was completely unexpected.
The researchers used a mindfulness-based stress reduction program developed by Jon Kabat-Zinn, which aims to reduce stress through meditation, self-awareness and being present in the moment. People in the mindfulness intervention spent two-and-a-half hours a week in class learning how to be mindful. They practiced mindful stretching and movement as well as breathing exercises to incorporate into their daily activities. Similarly, those in the exercise group attended two-and-a-half hour weekly sessions learning various exercise techniques and discussing strategies to change behavior. An hour of each class was dedicated to a group activity such as walking or jogging. Both groups were encouraged to do the intervention at home for 20 to 45 minutes each day.
Shifting From Structured Exercise To Overall Movement
While the interventions did not significantly increase time spent exercising or decrease sedentary time, participants generally maintained activity levels. This is important given the timeframe for the study. Researchers collected data during the fall and early winter months as part of a larger study focused on the cold and flu season. Seasonal variation in weather likely contributed to the sharp decline in activity for the control group, but the intervention groups did not experience the same drop-off. The study focused on exercise in bouts that lasted at least 10 minutes, but also tracked general physical activity, such as walking from the parking lot to the office or working in the yard. Both intervention groups saw smaller drop-offs in general activity levels than the control group.
Researchers used the 10-minute threshold to be consistent with guidelines of 150 minutes of moderate-to-vigorous exercise weekly, in bouts of at least 10 minutes. However, the recommendations only focus on a small percentage - 1.5 percent - of minutes in the week. That is one reason why updated federal guidelines emphasize overall activity regardless of length of time. There are clinical and cardiovascular health benefits to exercise training, but there are also important general health benefits from a more active lifestyle, Meyer said. Shifting from thinking we need to be in a gym for an hour at a time to thinking about being more active throughout the day helps people understand how physical activity could play a role in helping improve their health.
Resistance Training And Depression
A primary focus of Meyers research examines the benefits of exercise for people with depression. As part of a separate study, Meyer worked with researchers at the University of Limerick in Ireland and Karolinska Institutet in Sweden to test the effects of resistance training on symptoms of depression. The results, published inJAMA Psychiatry, found weightlifting and muscle-strengthening exercises significantly reduced depressive symptoms.
The meta-analysis, led by Brett Gordon at the University of Limerick, included 33 randomized controlled trials with more than 1,800 participants. Resistance training reduced symptoms for adults regardless of health status, the volume of training and whether or not strength improved. The results appear similar to the benefits from aerobic exercise found in other studies. Depression affects more than 300 million people, according to the World Health Organization. Meyer says resistance training could provide a treatment option with benefits that extend beyond mental health. In the paper, researchers explain the economic costs as well as other health risks associated with depression. Resistance training also gives patients an alternative to medication.
For general feelings of depression and the beginning phases of major depression, antidepressants and medications may not be very effective, Meyer said. There also is a shift toward finding options that do not require someone to start a drug regimen they may be on for the rest of their lives. Understanding that resistance training appears to have similar benefits to aerobic exercise may help those wading through daunting traditional medication treatment options. Future research is needed to know if aerobic exercise and resistance training work through similar channels to reduce depressive symptoms or work independently.
Stairs For Stimulation
A midday jolt of caffeine isn't as powerful as walking up and down some stairs, according to research from the University of Georgia. In a study published in the journalPhysiology and Behavior, researchers in the UGA College of Education found that 10 minutes of walking up and down stairs at a regular pace was more likely to make participants feel energized than ingesting 50 milligrams of caffeine - about the equivalent to the amount in a can of soda.
"We found, in both the caffeine and the placebo conditions, that there was not much change in how they felt," said Patrick J. O'Connor, a professor in the department of kinesiology who co-authored the study with former graduate student Derek Randolph. "But with exercise they did feel more energetic and vigorous. It was a temporary feeling, felt immediately after the exercise, but with the 50 milligrams of caffeine, we didn't get as big an effect."
The study aimed to simulate the hurdles faced in a typical office setting, where workers spend hours sitting and staring at computer screens and don't have time for a longer bout of exercise during the day. For the study, participants on separate days either ingested capsules containing caffeine or a placebo, or spent 10 minutes walking up and down stairs - about 30 floors total - at a low-intensity pace. O'Connor wanted to compare an exercise that could be achieved by people in an office setting, where they have access to stairs and a little time to be active, but not enough time to change into workout gear, shower and change back into work clothes.
"Office workers can go outside and walk, but weather can be less than ideal. It has never rained on me while walking the stairs," said O'Connor. "And a lot of people working in office buildings have access to stairs, so it's an option to keep some fitness while taking a short break from work." Study participants were female college students who described themselves as chronically sleep deprived - getting less than six-and-a-half hours per night. To test the effects of caffeine versus the exercise, each group took some verbal and computer-based tests to gauge how they felt and how well they performed certain cognitive tasks. Neither caffeine nor exercise caused large improvements in attention or memory, but stair walking was associated with a small increase in motivation for work.
There is still much research to be done on the specific benefits of exercising on the stairs, especially for just 10 minutes. But even a brief bout of stair walking can enhance feelings of energy without reducing cognitive function. "You may not have time to go for a swim, but you might have 10 minutes to walk up and down the stairs," OConnor added.