London, Feb 15 (IANS): Battling hard against depression? Walking or jogging, yoga and strength training seems to be the most effective exercises to ease depression, either alone or alongside established treatments such as psychotherapy and drugs, suggests a study.

The World Health Organisation (WHO) estimates that more than 300 million people worldwide have depression.

Exercise is often recommended alongside psychotherapy and drugs, but treatment guidelines and previous evidence reviews disagree on how to prescribe exercise to treat depression best.

The new evidence, based on a review of 218 trials involving 14,170 participants with depression and published by The BMJ, suggests that the more vigorous the activity, the greater the benefits are likely to be.

Researchers from Spain, Denmark, Australia and Finland noted that these forms of exercise "could be considered alongside psychotherapy and drugs as core treatments for depression."

Compared with active controls, large reductions in depression were found for dance and moderate reductions for walking or jogging, yoga, strength training, mixed aerobic exercises, and tai chi or qigong.

Moderate, clinically meaningful effects were also found when exercise was combined with SSRIs or aerobic exercise was combined with psychotherapy, suggesting that exercise could provide added benefit alongside these established treatments.

Although walking or jogging were effective for both men and women, strength training was more effective for women, and yoga or qigong was more effective for men.

Yoga was also more effective among older adults, while strength training was more effective among younger people.

While light physical activity such as walking and yoga still provided clinically meaningful effects, the benefits were greater for vigorous exercise such as running and interval training.

Exercise appeared equally effective for people with and without other health conditions and with different baseline levels of depression.

Effects were also similar for individual and group exercise. The team acknowledged that the quality of evidence is low, and very few trials monitored participants for one year or more.

Many patients may also have physical, psychological, or social barriers to participation, they noted.

Nevertheless, they suggest a combination of social interaction, mindfulness, and immersion in green spaces that may help explain the positive effects.

"Our findings support the inclusion of exercise as part of clinical practice guidelines for depression, particularly vigorous-intensity exercise," they said.

"Health systems may want to provide these treatments as alternatives or adjuvants to other established interventions while also attenuating risks to physical health associated with depression."