GLP-1 medications such as semaglutide and tirzepatide have changed how many people approach weight loss. Appetite drops, the scale moves, and for many people that is a real win.
But the scale does not tell you what you are losing. When you eat much less, your body can lose fat, and it can also lose muscle. That matters more than most people realize.
Why muscle is worth protecting
Muscle is not just about looks. It supports your joints, your balance, your strength for everyday tasks, and your metabolism. Losing it quickly, especially after 40, can leave you lighter but weaker, with a body that is harder to keep lean once the medication stops.
Research on GLP-1 medications suggests that a meaningful share of the weight lost can be lean mass, not only fat. Body composition scans in the SURMOUNT-1 tirzepatide trial found that some of the weight lost was lean mass.
What resistance training does
Lifting gives your body a reason to hold on to muscle while you are eating less. It also does the following:
Helps keep strength and function while the weight comes down
Supports bone density
Improves how the weight loss looks and feels, so you end up stronger and not only smaller
Builds a habit you can keep after you adjust or stop the medication
What this looks like in practice
Train two to three times a week. Full-body sessions built around the basic patterns: squat, hinge, push, pull and carry.
Lift with enough effort to matter. The signal that protects muscle comes from challenging loads, increased gradually and with good form.
Eat enough protein. When appetite is low, protein is often the first thing to slip. Ask your doctor or a dietitian what target fits you.
Respect low-energy days. Some people feel tired or nauseated on these medications. On those days, shorten the session or lower the intensity instead of skipping it entirely.
Move well before you move heavy. A movement assessment helps find stiff spots and weak links before you load them.
A note on safety
I am a trainer, not a doctor. Your GLP-1 prescription and dosing are decisions for you and your prescriber, so tell them about any new exercise program. Talk to them about dizziness, persistent nausea, or very low food intake.
How I work with clients on a GLP-1
I start with a movement assessment, then build a progressive strength plan that fits your energy and appetite. We combine resistance training, corrective exercise, and ELDOA where it helps, with simple nutrition guidance that focuses on protein. The goal is to lose weight while keeping the strength and shape you want to stay.
If you are on a GLP-1 or thinking about starting one, book a free consultation and we can build a plan around it.
