Just one hour of physical activity per week could prevent depression

*Sticking plaster that exercises heart failure patients’ legs without them having to move

New research suggests that a little weekly exercise could lower the risk of depression.A new study that examined data from almost 34,000 people has found that as little as 1 hour of exercise each week, regardless of intensity, can help to prevent depression. Depression is a very common disorder, the World Health Organization (WHO) calculate that more than 300 million people live with the disorder.

Treatments for depression usually involve medication, psychotherapy, or cognitive behavioral therapy, or a combination of these approaches.Recently, Australia-based not-for-profit group Black Dog Institute, who offer support to people with mood disorders, launched a one-month campaign encouraging people to exercise. They suggest on their website that regular physical activity can help to prevent and treat depression.

This is supported by research conducted by scientists from the Black Dog Institute in collaboration with colleagues from other institutions worldwide, including universities and health institutes from the United Kingdom, Australia, and Norway.

The results were published in the American Journal of Psychiatry.Also, people with heart failure may soon be able to exercise without actually having to move — by applying stick-on devices to their legs that effectively give their muscles a workout.

The effect is similar to physical exercise, according to a recent study published in the European Journal of Preventive Cardiology.It tends to affect older people and can occur as a result of numerous conditions, such as high blood pressure or a heart attack, which makes the heart’s pumping action weaker.

Heart failure causes symptoms such as severe tiredness, shortness of breath and chest pain. There is no cure — most treatments are aimed at trying to control symptoms or slowing the condition’s progression.Exercise is important, as it can help reduce symptoms, but patients can find it tiring because their heart is not strong enough to pump sufficient blood to their muscles.

The new approach — which scientists call functional electrical stimulation — uses low-energy electrical pulses to trigger muscles to move.It consists of small fabric patches that contain electrodes, which are attached to the skin around the muscles of the upper and lower legs. The electrodes are connected to a small, battery-powered generator.

In a recent trial, researchers at the Catharina Hospital in the Netherlands and Attikon University Hospital in Greece monitored 120 patients with heart failure.They found that those who used the patches daily were 60 per cent less likely to have needed hospital treatment during the one-year follow-up period, compared to those using a placebo device.

Exactly how this kind of electrical stimulation works is unclear, but one theory is that it triggers muscle contractions similar to those seen as a result of physical exercise. It may also improve blood flow.

Meanwhile, the first study – led by Prof. Samuel Harvey, from the Black Dog Institute – analyzed data collected from 33,908 Norwegian adults who were followed over a period of 11 years.

As Harvey explains, “We’ve known for some time that exercise has a role to play in treating symptoms of depression, but this is the first time we have been able to quantify the preventive potential of physical activity in terms of reducing future levels of depression.”

“These findings,” he adds, “are exciting because they show that even relatively small amounts of exercise – from 1 hour per week – can deliver significant protection against depression.”

The researchers analyzed data collected through the Nord-Trøndelag Health Study (HUNT), which is one of the largest population studies to date. The data collection and participant follow-up for HUNT took place between 1984 and 1997.

First, healthy participants were recruited and required to self-assess their physical activity status, including how often they exercise, and how intensely.Three different levels of intensity were reported: mild intensity exercise that was not followed by breathlessness or sweatiness, moderate intensity activity that produced breathlessness and sweatiness, and most intense exercise followed by physical exhaustion.

Later, the participants were given a self-assessment questionnaire – the Hospital Anxiety and Depression Scale – and asked to report any developing states of depression or anxiety.Confounding variables – including the participants’ socioeconomic status, alcohol and substance use, body mass index (BMI), new physical illnesses, and how well supported they felt on a social level – were also adjusted for to ensure the consistency of the results.

It was found that those who did not engage in any physical exercise to begin with were 44 percent more likely than their peers who exercised for 1 to 2 hours each week to develop depression.The protective effect of exercise was also observed, regardless of its intensity. “Most of the mental health benefits of exercise are realised within the first hour undertaken each week,” explains Prof. Harvey.

“With sedentary lifestyles becoming the norm worldwide, and rates of depression growing, these results are particularly pertinent as they highlight that even small lifestyle changes can reap significant mental health benefits,” he adds.

At the same time, however, the researchers did not note any benefits in the case of anxiety, as they found no link between physical exercise and whether or not participants developed this condition.The authors conclude that around 12 percent of depression cases might have been prevented if the participants had done at least 1 hour of physical exercise per week.

“We are still trying to determine exactly why exercise can have this protective effect, but we believe it is from the combined impact of the various physical and social benefits of physical activity,” says Harvey.He also emphasizes the importance of this study’s results in forming better health policies in the future, saying that only small adjustments to people’s lifestyles would be needed, enough to include a manageable amount of exercise.

“If we can find ways to increase the population’s level of physical activity even by a small amount,” he concludes, “then this is likely to bring substantial physical and mental health benefits.A consultant cardiologist at the Hammersmith Hospital in London, Dr. Punit Ramrakha, said: “Physical exercise has beneficial effects on the workings of the blood vessels in these patients and leads to a relative risk reduction of 23 per cent for death or hospitalization.

“However, compliance with fitness training programmes is unsatisfactory, due to limitations resulting from the advanced heart failure or coexisting conditions. “Functional electrical stimulation of leg muscles offers an alternative and represents an attractive option for heart failure patients who are unable or unwilling to exercise.”He adds: “There is now good evidence that this type of treatment improves wellbeing and clinical measures, which, in turn, translate to a significant reduction in hospitalisation.

“This new study should prompt heart failure teams across the country to review the provision of such treatments.”Meanwhile, a single jab of stem cells is being used to treat patients with heart failure. Doctors are harvesting stem cells from patients and then injecting them back into their coronary arteries to ‘rejuvenate’ them.

The researchers, at the Royan Institute in Tehran, believe the stem cells will help to do that: in an 18-month study with 60 patients, half will have the treatment and the others will have a dummy jab.