If you’re taking Ozempic, Wegovy, Zepbound, or Mounjaro and the scale is moving, I’m happy for you. That part is working. But here’s the part your prescriber probably didn’t walk you through: a huge percentage of the weight you’re losing might not be fat. It’s muscle. And once you’ve lost it, getting it back is a much harder project than losing it in the first place.
I’m Jonathan Catlett. I own Push Performance Training in Bixby, and over the last two decades and 20,000+ hours on the gym floor I’ve trained hundreds of people through weight loss, the old-fashioned way and now the GLP-1 way. The pattern I’m seeing with GLP-1 clients across Bixby, Broken Arrow, and South Tulsa is clear enough that I wanted to write this down.
What the research actually says
Studies on GLP-1 medications have found that when people lose weight on these drugs without strength training, somewhere between 25% and 40% of the weight lost can come from lean muscle tissue rather than fat. That number is why this matters. A 40-pound loss that’s 30% muscle is 12 pounds of muscle gone, muscle your body uses to stay upright, burn calories at rest, protect your joints, and keep you functional as you age.
The loss happens for three stacked reasons:
You’re eating a lot less. GLP-1s kill appetite. Most of my clients are eating 30-50% less food than before. When calories drop hard and fast, the body burns muscle for fuel unless it has a reason not to.
Protein intake tanks. When you’re not hungry, protein is the first macro that gets cut, because it’s the one that takes effort to prepare and chew. Carbs and small snacks are easier.
Most people don’t add strength training. They might walk more, but walking doesn’t signal to your body “keep this muscle.” Only resistance training does.
What it looks like on the gym floor
When someone comes in three or four months into a GLP-1 and hasn’t been lifting, the signs are consistent. Their grip is weaker than their frame suggests. They get winded on movements that should be easy. Their legs feel wobbly under a light squat. They look smaller but they feel fragile, not lean. That’s not fat loss. That’s body composition going the wrong direction underneath the number on the scale.
The “skinny but soft” problem
This is the outcome nobody on these medications signs up for, and it’s the one I see the most: people hit their goal weight and realize they don’t look or feel the way they imagined. They’re smaller, but they’re soft. Body fat percentage didn’t actually drop much because fat AND muscle both came off. The jeans fit, but the mirror isn’t what they pictured.
This is the “skinny fat” outcome, and it’s a specific side effect of losing weight without resistance training. On a GLP-1, without intentional strength work, it’s the default outcome, not the exception.
Why this matters beyond the mirror
Muscle isn’t just about how you look. It does real work:
Metabolic rate. Muscle is the most metabolically active tissue in your body. Less of it means you burn fewer calories at rest, which means the weight comes back faster when you eventually come off the medication.
Bone density. Resistance training signals your bones to stay strong. Weight loss without resistance training means bone density drops alongside muscle. This is a massive deal for anyone over 40, especially women.
Joint support. Your knees, hips, and low back are held in place by the muscles around them. Losing quad, glute, and core muscle while losing weight is a recipe for the joint pain you were hoping weight loss would fix.
Fall risk and independence. For anyone over 55, muscle loss directly correlates with fall risk and long-term independence. This isn’t a vanity issue.
The early signs you’re losing muscle, not just fat
You don’t have to wait for a DEXA scan to know this is happening. Watch for:
Strength drops. The weights that felt easy six weeks ago now feel heavy.
Energy crashes. Not the appetite-related dip, but actual weakness by mid-afternoon.
Looking “deflated.” Your arms, shoulders, and legs look softer instead of more defined.
Slower recovery. Stairs, grocery bags, kids, things that didn’t used to wipe you out now do.
The scale drops but your clothes fit the same. Classic sign body composition isn’t changing, just shrinking.
What to do about it
The fix isn’t complicated. It’s just non-negotiable.
1. Lift weights 2-3 times per week. Not 30-minute classes. Not just “getting steps in.” Progressive resistance training that challenges your muscles to do something they couldn’t do last month. This is the single biggest lever.
2. Hit your protein target. At minimum, 0.7 grams of protein per pound of goal body weight. For most people on GLP-1s, that means 100-150g of protein daily, which is a lot more than most hit without a plan.
3. Don’t stack endless cardio on top of the caloric deficit. More cardio on an already-low-calorie diet accelerates muscle loss. Walking is fine. Two-hour cardio sessions are not helping you.
4. Track something besides the scale. Strength numbers. Measurements. How clothes fit. Photos. The scale alone will lie to you about what’s happening.
Where Push Performance fits in
This is exactly the gap we built Push Performance to fill. We’re not a generic gym and we’re not trying to sell you the drug. We’re a personal training facility in Bixby where a coach is present for every single session, which matters because people on GLP-1s need programming that’s specifically designed around reduced recovery, lower energy, and the goal of keeping muscle while the drug handles the fat.
If you’re on a GLP-1 and you’re serious about not ending up smaller but weaker, come in. First session is a conversation, not a workout. We’ll look at where you are, what your medication is doing, and build a plan from there.
Book a No-Pressure First Conversation at Push Performance →
Push Performance Training is a personal training gym in Bixby, OK, serving clients across Bixby, Broken Arrow, and South Tulsa. Every session includes a coach on the floor. $280/month, no contracts.
Related Reading
- The #1 Mistake GLP-1 Users Make When They Start Training
- How to Eat Enough Protein on a GLP-1 When You’re Never Hungry
- Strength Training vs. Cardio on a GLP-1
Disclaimer: This post is for educational purposes and reflects the experience of a personal trainer working with GLP-1 clients. It is not medical advice. Talk to your prescribing provider about your specific situation.