Another HIIT for health: A few minutes of high-intensity exercise can prevent liver disease

SYDNEY, Australia — No matter how you like to exercise, a new study finds that getting in that daily workout can help people dealing with non-alcoholic fatty liver disease. Researchers from Western Sydney University add that not only does moderate-intensity continuous training (MICT) improve liver health, shorter and more intense workouts (high-intensity interval training or HIIT) work just as well.

Non-alcoholic fatty liver disease is one of the most common liver diseases in the world, affecting up to three in 10 people. Patients experience an excess buildup of fat in the liver without drinking much alcohol — a common trigger for liver disease. Developing NAFLD increases the risk of also becoming obese or suffering from other health problems.

With a lack of therapies which treat the disease, most of the current focus is on preventing NAFLD through lifestyle changes — like losing weight and getting fit.

Study authors reviewed over 28,000 previous studies on the link between exercise and liver health, focusing specifically on 19 that involved 745 people. Moreover, these studies examined liver fat levels using the current gold standard in non-invasive measurement techniques, such as proton magnetic resonance spectroscopy (H-MRS) and magnetic resonance imaging (MRI).

Their findings reveal that both regular aerobic exercise and short, high-intensity workouts lead to noticeable fat reduction in the liver. For people engaging in MICT, their liver fat levels dropped by 3.14 percent, while people participating in HIIT saw their fat levels drop by 2.85 percent.

Why is HIIT such a hit?

Researchers note that the results point to people at risk for liver disease being able to improve their health without the need for long and draining workout sessions. HIIT focuses on brief sessions of high-intensity aerobic exercise followed by rest periods. This makes these workouts quicker and generally take less energy to complete.

Previous studies show that HIIT can also improve heart function and accomplishes what normal exercise does in a fraction of the time.

Non-alcoholic fatty liver disease is a predictor of metabolic disorders, closely linked to the development and severity of various diseases such as type 2 diabetes,” says lead author and NICM Health Research Institute Postdoctoral Research Fellow Dr. Angelo Sabag in a university release.

“Our review demonstrates the importance of regular aerobic exercise as an effective therapy in those at risk, with both HIIT and MICT found to improve liver fat to similar degrees. It is useful information to know that by training harder in less time with HIIT, you can achieve the same results as MICT, which is ideal for those with a busy lifestyle and little time,” the researcher concludes.

“Another interesting finding was that even if people didn’t exercise at volumes sufficient to satisfy the recommended physical activity guidelines, they could still achieve clinically significant improvements in liver fat so long as they exercised regularly above a moderate intensity.”

The study is published in the Journal of Clinical Endocrinology and Metabolism.