A recent study led by researchers at the University of the Sunshine Coast (UniSC) suggests that high-intensity interval training (HIIT) could be one of the most effective ways for older adults to reduce body fat while maintaining muscle mass.
The research compared different exercise intensities in healthy older adults and found that all levels of exercise produced some fat loss. However, only HIIT helped participants preserve lean muscle mass.
“We found that high, medium and low intensity exercises led to modest fat loss, but only HIIT retained lean muscle,” said lead author and exercise physiologist Dr Grace Rose from the University of the Sunshine Coast.
Exercise intensity and body composition
The study explored how exercise intensity affects body composition, an important factor in overall health as people age.
According to Dr. Rose, moderate-intensity exercise also helped reduce body fat, but it had its downsides.
“While moderate training reduced fat mass, it also caused a small decrease in lean muscle,” he said.
“Both high and moderate intensity improved the composition of weight carried around the abdomen. Further analysis of the low intensity results is needed.”
Dr. Rose noted that the findings are particularly important because changes in body composition are linked to the development and progression of many chronic diseases later in life.
Six months of supervised exercise
The study included more than 120 healthy older adults from the Greater Brisbane region. Participants completed three exercise sessions at the gym each week over a six-month period.
On average, participants were 72 years old and had an average body mass index of 26 kg/m.2what is considered normal for adults over 65 years of age.
The findings were published in the journal. Maturitas. Researchers from UniSC’s Healthy Aging Research Group, as well as the University of Queensland, participated in the project.
Why HIIT can protect muscles
UniSC Associate Professor of Physiology and study co-author Mia Schaumberg said the research comes at a useful time, as many people focus on health and fitness goals at the start of a new year.
“Now that the holiday season is behind us for most of us and New Year’s resolutions are in full swing, this research can help inform people’s plans for healthy aging in 2026,” he said.
In the study, HIIT consisted of repeated short intervals of very challenging exercise followed by easier recovery periods.
“The high-intensity training in this study involved repeated bursts or short intervals of very intense exercise (in which breathing is heavy and talking is difficult) alternating with easier recovery periods.
“HIIT probably works better because it puts more pressure on the muscles, giving the body a stronger signal to preserve muscle tissue rather than lose it.”