Taking a GLP-1? This is the ‘essential’ habit to maintain in your routine to stay healthy

The use of weight loss injections in the UK is showing no signs of slowing down, but research into the short and long-term impact of taking these drugs is still emerging. While we know that GLP-1 medication (aka a weight loss jab) is effective at speeding up fat loss, new evidence is revealing the impact it can have on other parts of the body - namely, our muscles.

A new report by Les Mills, in collaboration with the ukactive Research Institute, found that when people use medications such as Ozempic, Wegovy and Mounjaro, 20 to 50% of the weight they lose is lean body mass – that's everything in your body apart from fat, including muscle.

With muscle loss comes a loss of strength and function, increasing the risk of falling over (and not just when we're older) and making everyday tasks (like climbing the stairs) feel a lot harder. The report's authors say that the magnitude of lean body mass loss is similar to that resulting from bariatric surgery, cancer treatment, or 10 years of ageing, stating: “The loss of lean body mass (muscle and bone) associated with GLP-1 receptor agonists can have a significant negative impact on long-term health.”

The rate of muscle loss is so high because these medications suppress users' appetites, meaning weight loss can be dramatic. Some people lose 15 to 20% of their body weight in six months.

The solution? A good exercise routine. We need strong muscles to maintain bone mass density, help our posture and joint strength, and protect long-term health.

What exercise should you do on a GLP-1?

The review's studies concluded that resistance training, combined with a healthy diet, is essential to prevent muscle loss. Bryce Hastings, head of research at Les Mills, says: “Regular strength training is vital to our health at all stages of life, but the research suggests this is especially true for people taking weight loss medications.

"In addition to strength training two to three times a week, it's recommended that people taking weight loss medications accumulate 150 minutes of moderate to vigorous physical activity per week. Studies have shown this helps continue fat mass loss in the weight maintenance phase of treatment and lessen weight regain after treatment has stopped," he says.

Strength training can include anything that uses resistance to put pressure on the muscles, bones, and joints. For example, you could do a dumbbell workout at home, join the gym (and speak to a personal trainer for advice on creating a routine), or practice callisthenics, using your own body weight as resistance.

Moderate-intensity exercise includes cardio activities like walking, swimming, and cycling workouts, where you'll be working up a sweat but still be able to hold a conversation. Vigorous-intensity exercise is harder on the body and includes running, treadmill workouts, HIIT, and others that lead you to sweat and feel out of breath.

The report’s authors are calling for the Government and nutrition and fitness industries to improve the support and care for those using weight loss drugs, to make sure they’re aware of how their strength and overall health can be maintained.