HIIT preserved muscle in six-month trial of older adults
A study of healthy adults in their 70s found high-intensity intervals reduced fat while maintaining lean muscle, researchers said.
By Lucas Ferreira · Science & Environment Writer
3 min read
High-intensity interval training was the only exercise approach in a six-month study that helped healthy older adults lose body fat without losing lean muscle, according to researchers at the University of the Sunshine Coast. The finding matters for aging adults because body composition changes are tied to the development and progression of many chronic diseases later in life, lead author Dr. Grace Rose said.
The study compared high-, moderate- and low-intensity exercise among more than 120 adults from the Greater Brisbane region. Participants completed three supervised gym sessions each week for six months, according to the university.
Participants were 72 years old on average and had an average body mass index of 26 kg/m2, which the researchers described as normal for adults over 65. The findings were published in the journal Maturitas.
What the study found
Rose, an exercise physiologist at the University of the Sunshine Coast, said high-, medium- and low-intensity exercise all produced modest fat loss. Only the high-intensity interval training group maintained lean muscle, she said.
Moderate-intensity training also reduced fat mass, according to Rose, but the researchers saw a small drop in lean muscle in that group. Rose said both high- and moderate-intensity exercise improved the composition of weight carried around the middle, while further analysis is needed for the low-intensity results.
Lean muscle is an important measure in older adults because muscle tends to become harder to maintain with age. The university said the study focused on body composition rather than weight alone, a distinction that can matter when fat and muscle change in different directions.
How the HIIT sessions worked
Associate Professor Mia Schaumberg, a physiology researcher at the University of the Sunshine Coast and a co-author of the study, said the high-intensity sessions used short repeated intervals of very demanding exercise followed by easier recovery periods.
In practical terms, Schaumberg said the hard intervals were intense enough that breathing became heavy and conversation was difficult. She said HIIT may have performed better because the muscle stress gave the body a stronger signal to retain muscle tissue.
The project included researchers from the University of the Sunshine Coast’s Healthy Ageing Research Cluster and The University of Queensland. The journal paper lists Grace Rose, Emily Hume, Daniel Blackmore, Jules Mitchell, Samuel Belford, Tina Skinner, Maryam Ziaei, Stephan Riek, Perry Bartlett and Mia Schaumberg as authors.
The study does not mean every older adult should start high-intensity training without considering personal health status. The reported trial involved healthy older adults taking part in supervised gym-based sessions, and the researchers framed the results as evidence that exercise intensity can affect body composition in later life.
This story draws on original reporting from ScienceDaily.