Heart failure patients may exercise more when they have support from family and friends, a U.S. study suggests.

Heart failure causes the heart to pump too little blood through the body and leads to shortness of breath, so physical activity can often be a struggle for these patients.

Yet "heart failure patients benefit from exercise for the same reasons that everyone does, to reduce their risk of further cardiovascular disease and improve their aerobic capacity," said Ann Knocke, a physical therapist in cardiac rehabilitation at Newton-Wellesley Hospital in Massachusetts who wasn't involved in the new study.

Dr. Lauren Cooper of Duke University in Durham, North Carolina, who led the research, told Reuters Health that her team "looked at psychosocial reasons that may impact participation in an exercise program, and found that patients with higher levels of social support and fewer barriers to exercise exercised more than patients with lower levels of social support and more barriers to exercise."

"This is important because patients who exercised less had a higher risk of death from cardiac causes or hospitalization due to heart failure compared to patients who exercised more," Cooper added by email.

Cooper and colleagues analyzed data from more than 2,200 people with heart failure. All of them received standard care, including education on how to get more exercise, and half of them also got 36 supervised workouts over three months.

After one year, patients who reported the highest levels of social support - such as family members who help or friends who listen - exercised an average of 118 minutes each week, while people who said they got little support logged only about 92 minutes a week.

By the end of the year, patients with fewer barriers to exercise - such as lack of transportation or childcare, limited finances or bad weather - also got moving more often. With fewer obstacles, patients got an average of 169 minutes of exercise, compared to 86 minutes for people who encountered the most barriers.

Only one-third of the patients assigned to supervised workouts were fully compliant with their exercise programs.

Exercising more minutes per week, however, was associated with a reduced risk of death from cardiovascular causes or hospitalizations for heart failure.

In their report, published in the journal Circulation: Heart Failure, the authors admit that only patients deemed able to exercise were included in the study. Also, they acknowledge, men and younger patients were overrepresented.

It's particularly challenging to encourage heart failure patients to exercise because they are generally older and frailer with multiple diseases and medical problems, noted Dr. Massimo Piepoli, chairman of the committee on exercise training and physiology for the Heart Failure Association of the European Society of Cardiology.

"Increased awareness is crucial -being physically more active and independent are crucial for everybody but in particular for the frailer patients," Piepoli, who wasn't involved in the study, said by email.

Knocke, the cardiac rehab physical therapist, said by email that improving exercise rates among heart failure patients may depend on more doctors referring people to cardiac rehabilitation programs as well as more supervision and support to help patients stick with the program.