Turns out, people with existing heart problems or who are at the risk of developing them are ignoring medical advice and are not exercising enough.

Scientists from the University of Adelaide looked at the exercise habits of 3000 people from the general population in South Australia and Southern Brazil. New medical treatments have helped people to live longer despite these health problems, but this is causing an escalating burden on public health systems worldwide. "Previous research has tended to assess the benefits of exercise habits of patients with cardiovascular disease who follow an exercise plan developed by their doctor," said the study's author David A. Gonzalez-Chica.

"There is evidence that more than 70 percent of people who suffer from or who are at risk of developing a heart condition due to diabetes, high blood pressure or high cholesterol, do not follow a proper program of regular moderate or vigorous exercise, which is critical for avoiding further complications and even mortality. "The scale of this critical public health issue is, therefore, being under-reported," said Gonzalez-Chica.

People with heart problems are living longer - especially in high - income countries such as Australia - but their long-term quality of life is being adversely affected because they are avoiding moderate or vigorous exercise. Current guidelines suggested that at least 150 minutes of moderate or vigorous physical activity a week is recommended. "Many people living with cardiovascular disease, or who are at risk of developing the condition due to existing health problems are exercising too little. Light exercise such as taking a walk isn't sufficient. According to our study, walking for at least 150 minutes a week was also beneficial for improving the quality of life, even when the individual had a heart condition."

"Deaths due to heart conditions account for 31% of deaths globally. While most of these deaths occur in low and middle-income countries such as Brazil, the condition accounts for an increasing proportion of non-communicable diseases in high - income countries such as Australia," said Gonzalez-Chica. Worldwide, the burden of cardiovascular disease and its risk factors is a growing public health issue. According to the World Economic Forum, non-communicable diseases will cause a global loss of USD 47 trillion over the following two decades, with cardiovascular disease being the most important contributor. The study appears in the journal PLOS ONE.