The weight-loss journey for a growing number of Australians using “miracle” medications must include exercise or risk long-term health problems, reports KATELYN CATANZARITI.

Doctors are being urged to prescribe exercise alongside “miracle” weight-loss drugs to prevent devastating muscle and bone loss as millions more Australians gain access to the medications.

With GLP-1 drugs such as Ozempic, Wegovy and Mounjaro increasingly used to treat obesity and metabolic disease, Australia’s peak physical activity body warns exercise isn’t optional but essential to prevent long-term harm.

AUSactive chief executive Ken Griffin says rapid weight loss without structured physical activity can strip muscle and bone, increasing frailty, falls and hospitalisations.

“If taxpayers are funding GLP-1s, exercise must be built into prescriptions,” he says.

“For GLP-1 users, a fitness professional should be as familiar as their GP or pharmacist.”

A new Deakin University study has found people using GLP-1s without exercise risk losing lean muscle mass, strength and bone density – factors linked to falls, fractures and chronic health complications.

The warning comes as the federal government prepares to expand Pharmaceutical Benefits Scheme (PBS) access to weight-loss drugs, potentially opening the door for millions more Australians to use them.

About one in three Australians are overweight or obese, while health system costs linked to preventable lifestyle conditions run into the tens of billions of dollars annually.

Mr Griffin says exercise must be formally embedded into GLP-1 prescribing and referral pathways.

“Exercise isn’t optional, it’s the safety net that protects muscle, protects bones, supports metabolism and prevents future hospitalisations,” he says.

“The gym, studio or trainer isn’t a luxury add-on – they’re a crucial part of a safe weight-loss plan.”

Fitness educator Mish Wright, who upskills exercise professionals nationwide on working with GLP-1 clients, says the drugs don’t exclusively target fat.

“GLP-1s don’t selectively remove fat. You lose muscle as well and we need to be building that up,” she says.

“The researchers have all come out and said GLP-1s will work best in conjunction with an exercise program and in particular a strength-based training program.”

Ms Wright says women face particular risks, especially during midlife and perimenopause.

“Osteopenia and osteoporosis are major issues for women in particular.

“A lot of women don’t even know they have osteopenia until they fall and break a hip.”

She says resistance and weight-bearing exercise must be central but messaging around strength training often alienates people.

“There is one message when it comes to weight training and it’s a message that happens in the gym, with big weights and a bit of grunting – and for a lot of people that is incredibly off-putting.

“There are more ways to strength train than the weight section at the gym.”

For Andrea, a 44-year-old small business owner from regional Victoria, GLP-1 medication was not a cosmetic choice but a medical intervention.

“I was pre-diabetic starting in 2019. That’s when we first saw it in the blood tests,” she says.

“I had seen a dietician, was still doing my regular exercises and I just could not shift the weight.”

Andrea says medication for bipolar disorder compounded the problem.

“The medications that I have to take for bipolar disorder increase my appetite and decrease my metabolism, so I was fighting a losing battle,” she says.

When she raised GLP-1s with her GP in 2024, the decision was blunt.

“For you it’s not a matter of if, it’s a matter of when you will end up on these,” she recalls being told.

“Do you want full-blown diabetes in order to have it covered by the PBS or do you want to go on them now?”

Andrea started on Ozempic before switching to Wegovy due to supply shortages.

“If you weren’t on the PBS, they just weren’t dispensing it,” she says.

“She switched me over to Wegovy, which cost about a hundred dollars more a month. It was just what I had to do.”

The early months were difficult.

“It was tricky at first – you’re having to relearn how to eat, basically,” she says.

“There was nowhere for the food to go.”

Eating out often triggered severe discomfort.

“That’s when it would create the most pain in my stomach and it would lead me to vomit,” Andrea says.

Despite the side effects, the health benefits were dramatic.

“Before I was on the GLP-1, I was 7.8. About seven months later I was down to 5.6,” she says of her blood sugar levels.

“She said, ‘I’ve never seen it drop this quickly.'”

As weight came off, Andrea says movement became possible again after years of pain from plantar fasciitis.

“Losing all the weight gave me the confidence to get back into physical activity,” she says.

She now attends Pilates twice a week and exercises at home.

Experts say Andrea’s experience highlights why exercise must begin alongside medication, not after weight loss has occurred.

“Having an exercise program in place is of the utmost importance, of which strength training is going to be a part of it,” Ms Wright says.

Mr Griffin says AUSactive is calling for a National Physical Activity Strategy to ensure exercise is routinely prescribed with GLP-1 drugs.

“Exercise must sit alongside medication – not come after it,” he says.

For Andrea, the message for GLP-1 users is simple.

“I don’t regret being on them whatsoever,” she says.

“But it isn’t as simple as injecting once a week and nothing changes.”