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May 3, 2026
Christine Bürg & Marianne Waldenfels
Many people lose weight quickly with Ozempic, Wegovy or Mounjaro – but also lose muscle. Physiotherapist Nils Stützer explains how to prevent it.
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Weight loss injections like Ozempic, Wegovy or Mounjaro are considered breakthroughs in obesity treatment. But experts warn: without targeted training, there is a risk of muscle loss.
“Muscle loss is most effectively prevented by regular strength training,” explains physiotherapist and personal trainer Nils Stützer. This is precisely where the key lever lies to sustain the positive effects of the therapy in the long term.
The mechanism of GLP-1 medications is as effective as it is profound: they reduce appetite, slow gastric emptying and lead to a significantly lower calorie intake.
What is medically intended, however, comes with a downside. The body receives less energy and — crucially — often less protein. At the same time, many patients become less physically active.
The result: the body not only draws on fat reserves, but also breaks down muscle tissue.
“Nutrition plays a crucial role. Even with optimal training, muscle loss can occur without proper nutrition,” emphasizes Nils Stütze. Insufficient protein intake is particularly critical.
The good news: Muscle loss is not an unavoidable side effect. According to Nils Stützer, one form of training is particularly crucial:
“I recommend classic set training on machines, i.e., hypertrophy training.”
Especially for beginners, he sees great advantages in this. “Computer-assisted machines offer a great advantage because they guide and support the speed of movement, range of motion, and execution.”
This not only reduces the risk of injury but also makes it easier to start—a crucial factor since many patients have little experience with exercise before starting therapy.
Other forms of training can also be beneficial. "I also recommend calisthenics, which is training with one's own body weight, as well as functional training with small equipment like barbells or dumbbells," says Stützer.
However, caution is advised here: "Functional training requires good body awareness because it demands higher movement control. Otherwise, compensatory movements may occur."
One of the most common questions: How much training is necessary to prevent muscle loss? Stützer clearly distinguishes between prevention and active muscle building.
Even a relatively low effort can help maintain muscles. "To prevent muscle loss, I recommend training at least once or twice a week for 20 to 30 minutes," he explains. The intensity is crucial: "The last repetition should be noticeably strenuous."
Anyone who also wants to build muscle specifically should train more frequently. train. “For muscle building, at least two to three sessions per week of 45 to 60 minutes are recommended.”
It's less about rigid training plans and more about the right intensity:
“It's secondary whether you do 12 or 15 repetitions – what matters is getting close to your personal limit in each set.”
As a guideline, he suggests an intensity of around 8 on a scale of 0 to 10. Especially important: “At least twice a week, all major muscle groups should be trained.”
For many patients, structure is crucial. Stützer recommends a combination of strength, movement, and recovery.
A typical weekly schedule might look like this: Two sessions strength training, complemented by one session of mobility, for example yoga, as well as moderate endurance training such as walking, running, or cycling. This mix ensures that the muscles are maintained without overwhelming the body.
The special challenge: The body is in a changed metabolic state while taking Ozempic. "I have experience with patients who use a weight loss injection in parallel," says Stützer. A similar pattern always emerges: Many start from a state with little movement.
"This means that initially, body awareness and training understanding need to be built." Starting too quickly can be counterproductive. "It is important to gradually and structurally introduce the body to loads and consider physiological adaptation processes."
It should also be noted that side effects can play a role. “Initially, fatigue, weakness, or circulatory problems may occur.”
That's why he recommends regularly checking your own condition: “Before each training session, you should ask yourself how resilient you currently are – for example, based on heart rate or general well-being.”
Besides training, nutrition is the second crucial component. “First, the basal metabolic rate should be determined to know the body's minimum energy requirement,” Stützer explains.
Particularly important is the protein intake. For muscle maintenance, he recommends about 1.2 to 1.4 grams of protein per kilogram of body weight daily. Those who actively want to build muscles should even increase to 1.6 to 2.2 grams.
A balanced diet with as little sugar and as few highly processed foods as possible forms the basis. In practice, it can be difficult to achieve these values through diet alone. “Targeted supplementation can be useful,” says Stützer.
Creatine can also play a supportive role: "It improves the energy supply in muscles and can thereby increase training intensity."
In the end, it's about more than just training or nutrition alone. "What matters is a sustainable lifestyle change," emphasizes Stützer. Without this, there is a risk of a yo-yo effect after stopping the medication or the desired results not being achieved.
The weight loss injection can be an effective starting point - long-term success, however, is created through habits.
Weight loss injections like Wegovy enable effective weight reduction. But without targeted countermeasures, part of this success can be lost – in the form of muscle mass.
The solution lies in a clear concept: structured strength trainingsufficient protein intake, and a conscious approach to one's own body.
Or, as Nils Stützer summarizes: "The key is that the body is regularly challenged – only then does it have a reason to maintain muscle."
