HOW TO MAINTAIN MUSCLE MASS WHEN YOU’RE ON A GLP-1
If you’re trying to lose weight, it’s important to go about it the right way. It’s also important to lose the right kind of weight. So as your weight goes down, it’s good to assess whether you’re losing too much muscle in the process. And if you are taking a GLP-1 receptor agonist semaglutide — an FDA-approved drug for managing diabetes and, for some, obesity — maintaining and building muscle should be a priority alongside other healthful lifestyle choices.
Here’s what to know about how weight loss drugs such as Ozempic, Wegovy, and Mounjaro impact your body and how to best eat and exercise while taking them.
How Does GLP-1 Affect Muscle?
The downside to any weight loss is that muscle is also lost if we are not mindful to maintain it. Although much has been made of muscle loss while taking GLP-1 medications, “all weight loss can lead to muscle loss,” says Alina Elperin, MD, an internist and obesity medicine specialist, a clinical assistant professor of medicine at University of Chicago Pritzker School of Medicine, and a member of the outreach committee of the Obesity Medicine Association.
However, if someone is losing weight rapidly, which can happen on a GLP-1 medication, it’s essential to prevent that from happening. “The GLP-1 medications are so effective for weight loss [compared to] prior medication or non-medication attempts, but with more weight loss, more muscle is lost,” explains Dr. Elperin. “When you lose weight rapidly, you lose more muscle compared to gradual weight loss.”
Why You Need Muscle Mass to Support Weight Loss
Elperin notes that many patients lose about 15 percent or more of their body weight while on a GLP-1 medication. Whether you’re on a weight loss drug or losing weight due to other lifestyle changes you’re making, building muscle is the best way to keep that weight off or lose additional weight.
“[Losing muscle] slows down our metabolism quite a bit,” says Elperin. “A slower metabolism means weight loss will likely plateau despite a consistently healthy diet or we might see some weight regain. In addition, losing muscle mass can increase frailty and cause a worsening of joint, bone, and balance problems. This is why it is so important to maintain muscle mass while on a GLP-1 medication.”
So if you’re on a GLP-1, building and maintaining muscle is one of the best goals you can set for yourself.
Why Our Muscles Are So Important
For both weight loss and weight maintenance, the research is pretty clear: Building strength is one of the best health goals you can set for yourself. Muscle is the key to a higher metabolic rate, not to mention better longevity and quality of life.
Maintaining muscle is something that should be top of mind at any age, but it takes on even more importance in middle age and beyond as it impacts mobility and prevents injuries, explains Suzanne Ferree, MD, founder of Vine Medical Associates and the Cellular Medicine Institute, and author of Counterclockwise: Using Peptides to Renew, Rejuvenate, and Rediscover.
“Maintenance of muscle mass is so important over the age of 40, whether on a GLP-1 or not,” Dr. Ferree says. “Muscle helps you to stay mobile and active as you age, and strong muscle is associated with strong bones to prevent age-related fractures and associated debility. Plus, muscle is pretty. Without it, our skin hangs over our fat and bones rather than defining our body shape.”
Exercising muscle also secretes myokines — signaling chemicals that help our bodies stay youthful, Ferree adds.
How Do You Keep Muscle on a Semaglutide?
If weight loss and muscle loss can happen so quickly on a GLP-1, how can you hold onto that muscle? And hopefully increase it?
It won’t come as a surprise that for any weight loss journey, exercise is a must. But for those looking to up their muscle mass, resistance exercise is the golden ticket.
“Resistance exercise is powerful exercise if you want to improve muscle health, manage weight, and improve glycemic control,” says Vivian Yu, RDN, a fitness expert and founder of Gym Near Me. “But starting with any exercise should be slow and steady, as a heavy lift or move could adversely affect your health.”
For adults, the current guideline provided by the American College of Sports Medicine is to engage in muscle-strengthening exercises on two or more days each week, says Yu.
She suggests two sessions of 20 to 30 minutes each per week, which can involve any combination of resistance exercises like lunges and squats or using resistance bands and dumbbells. (Note: Before starting any exercise regimen, it is always best to consult with your primary care physician.)
One study suggests you can start seeing muscle mass improvement in just 10 weeks. Those who participated in 20 minutes of aerobic activity three days per week plus resistance exercises twice a week — consisting of one set (8 to 12 repetitions) of 8 to 10 resistance exercises — increased their lean weight by 1.4 kg (about 3 pounds), reduced fat weight by 1.7 kg (about 4 pounds), and reduced body fat by about 2 percent after 10 weeks.
Maintaining muscle is great for your heart and longevity of life, too. According to a scientific statement, adults who participate in 30 to 60 minutes of weekly resistance training have a 15 percent lower risk of all causes of mortality and 17 percent lower risk of cardiovascular disease, compared to those who report no resistance training.
As you begin resistance training, pay attention to your body and how it responds, says Yu. Feeling a bit of fatigue is normal, but if it gets too intense, don’t be afraid to scale down and slowly work your way up to higher weights or more repetitions.
Correct form is also very important to make sure you can sustain resistance training for the long haul and that your hard work won’t get derailed by an injury.
Both Yu and Ferree recommend investing in a personal trainer for a few sessions, or a strength-training class led by an instructor, so you can ensure you’re doing the exercises correctly and aren’t tapping into the wrong muscle groups.
If joint pain or mobility prevents you from using dumbbells or weights, an alternative is to use a cardio machine with a high resistance load that allows you to either stand or sit.
“A stationary bike with some resistance turned up or an elliptical or treadmill with some incline also works well,” says Elperin. “For patients who struggle with balance and mobility or joint pain, seated resistance training exercises can go a long way.”
Eating to Maintain Muscle
While strength training is essential, it’s important not to overlook another vital component of muscle maintenance: protein consumption.
Elperin suggests aiming for 1 gram of protein consumed per kilogram of your body weight. However, if you are experiencing rapid weight loss — especially for those on a GLP-1 — you may want to increase that protein consumption to 1.2 grams of protein per kilogram of body weight.
Good protein sources include eggs, seafood and fish, lean meats, dairy (such as nonfat plain Greek yogurt or cottage cheese), beans, legumes, and nuts, suggests Elperin.
The Bottom Line
Convinced that weight training is beneficial not only for your weight, but also for your overall health and well-being? That’s great! As with any new exercise, consult with your primary care physician first and then incorporate it into your routine, starting slowly and then working your way up to the recommendation of twice a week or more.
Editorial Sources and Fact-Checking
- Westcott WL et al. Prescribing Physical Activity: Applying the ACSM Protocols for Exercise Type, Intensity, and Duration Across 3 Training Frequencies. The Physician and Sportsmedicine. March 13, 2015.
- Paluch A et al. Resistance Exercise Training in Individuals With and Without Cardiovascular Disease: 2023 Update: A Scientific Statement from the American Heart Association. Circulation. December 7, 2023.