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Putting diet-exercise combo to the test for snorers

Putting diet-exercise combo to the test for snorers

Wednesday, February 01, 2023

Our researchers are testing out the twin benefits of diet and exercise as a more effective treatment for obstructive sleep apnea (OSA) compared to dieting alone. 

Weight loss is a proven therapy for night-time snoring and OSA. But scientists at the Woolcock Institute of Medical Research are concerned that the very low energy diets many people use tend to reduce muscle as well as fat, which may negate some of the benefits of weight loss.

"We think that partnering an exercise regimen with the diet may protect against muscle loss and bring greater health benefits to the many Australians living with OSA," says chief investigator Dr Elizabeth Cayanan. "And, importantly, it's a treatment that can be easily accessed in the community without the need for medical equipment."

To test out the benefits of a diet and exercise together, Dr Cayanan and her team are running the weight loss, obstructive sleep apnoea and functional exercise (WOLF) trial. They are enlisting 30 men aged 18 to 55 in the greater Sydney area who have untreated moderate to severe OSA.

All volunteers will follow a commercially available very low energy diet for three months, with half of the recruits randomly assigned to follow a high intensity functional exercise program.

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The workouts will be supervised by a qualified trainer at a gym, and will include both resistance and aerobic exercise with increasing intensity. Measures of body composition, health, OSA severity and general wellbeing will be taken at the start and at the completion of the diet and exercise program.

"We want to see if this combination of diet and exercise will improve OSA severity and preserve muscle mass during weight loss," Dr Cayanan explains. "If this pilot study is successful we can test the approach on more people and develop a safe and easily accessible alternative to continuous positive airway pressure that anyone with OSA can try at home."

Participants need to be overweight or obese men and have an OSA diagnosis but not be using continuous positive airway pressure (CPAP). They will also be required to visit the Woolcock Clinic in Sydney for four short clinical consultations and two overnight sleep studies.

For more details about eligibility and to volunteer, go to the study web page.

About OSA

One in ten middle-aged Australians have OSA, a snoring disorder that disrupts breathing, limits blood oxygen levels and interferes with sound sleep. People with OSA have significantly higher than average rates of stroke, heart disease, high blood pressure, diabetes, and depression, and are more likely to feel excessively tired during the day.

CPAP is currently the 'gold-standard' treatment option for OSA. During CPAP treatment, air is gently pumped into the airways overnight to prevent their collapse. However, non-adherence is an issue and cardiovascular problems are often not corrected.

For details on how to get involved in the WOLF study, email the study coordinator Fraser Lowrie on

Find out more about the study.

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