Keep Muscle on a GLP-1: Strength and Nutrition, Blue Springs

To keep your muscle on a GLP-1 like Ozempic, Wegovy, Zepbound or Mounjaro, lift weights two to three times a week and eat protein first at every meal. Then track your body composition, not just your weight, so you can see that the weight coming off is fat.

At CrossFit Cerberus, 200 NW 11th Street in Blue Springs, we put one-on-one nutrition coaching, InBody scans and coached strength training under one roof, and you can start with a free Nutrition Strategy Session.

Updated November 14, 2026. Written by Carl Neidholdt, Precision Nutrition Level 2.

How much of the weight you lose on a GLP-1 is muscle?

Without structured strength training, a large share of GLP-1 weight loss can be lean tissue. A 2025 joint advisory from four obesity and nutrition societies looked at the STEP 1 trial of semaglutide. Of an average 13.6 kg lost, 8.3 kg (62%) was fat and 5.3 kg (38%) was lean mass. Muscle is about half of lean mass, so the authors put muscle at about 20% of the weight lost.

Cleveland Clinic makes the key point: the muscle loss comes from the weight loss process, not from the drug itself. Lose weight fast while eating very little, and your body gives up some muscle along with the fat.

What the scale measures

The scale is accurate, but it weighs everything at once:

• Muscle
• Fat tissue
• Water, from hydration and inflammation
• Bone mineral
• Glycogen, the carbohydrate stored in your muscles and liver
• Day to day hormonal shifts

When the number drops, most people hope it is fat. A body composition scan replaces that hope with a measurement.

How semaglutide and tirzepatide work, in plain terms

GLP-1 medications copy a gut hormone your body already makes after you eat. That hormone tells your brain you are full, slows how fast your stomach empties, and helps your body handle blood sugar. The result is less hunger and less food noise. Semaglutide is the drug in Ozempic and Wegovy. Tirzepatide is the drug in Mounjaro and Zepbound, and it also acts on a second gut hormone called GIP.

At the dinner table they work the same way: you feel full sooner and stay full longer. That is why they work for weight loss, and it is also the catch. When you are barely hungry, it is easy to go a whole day on a few bites, and protein is usually the first thing to fall short. Low protein plus no lifting is how muscle leaves along with the fat.

Strength training on a GLP-1: what works

How often and what kind

Plan on two to three strength sessions a week. The JAMA Internal Medicine patient page recommends 2 to 3 sessions a week of about 30 minutes, plus walking that builds from 10 minutes a day to 150 minutes a week. The joint advisory sets the bar a little higher: at least 3 strength sessions a week plus at least 150 minutes of moderate cardio. It also warns that “increased protein intake alone is likely inadequate” without structured resistance training.

Cover the basic patterns: squats, hinges (a deadlift or kettlebell swing), pushes, pulls and carries. Then let the load go up over time.

What the newest trial found

The T-REx trial, published in Nature Medicine in November 2026, is the clearest answer yet. Researchers followed 120 adults aged 50 to 70 on tirzepatide for 40 weeks. Half did three supervised group strength sessions a week, and they made 91% of them.

• Weight loss was the same in both groups: 22.61 kg and 22.28 kg.
• Fat loss was about the same too: 17.19 kg and 17.98 kg.
• Lean tissue loss was 4.67 kg without training and 3.57 kg with it. The university news release calls that 25% less lean tissue lost.
• Strength rose 10% to 18% with training. Without it, strength fell 6% to 9% on the bench press, lat pulldown and knee extension.
• Lean loss leveled off after week 24.

In plain words, lifting did not slow the weight loss. It changed what was lost, and it turned a strength loss into a strength gain.

Training through dose increases and low-appetite days

Start light in the first, lowest-dose weeks. Cleveland Clinic suggests 10 to 15 minutes a day of light activity at first, then building weights, reps and sets from about week five. On low-appetite days, eat some protein before you train and keep drinking water, because thirst drops along with hunger. After a dose increase, scale the session instead of skipping it. If you feel dizzy, or you also take diabetes medication, coordinate your training with your prescriber.

Starting over 50, new to lifting, or with achy joints

You can start where you are. At Cerberus, strength work is scaled to you:

• Start Here Workshop: learn the basic lifts step by step.
• Personal Training: one-on-one sessions built around your history and your joints.
• Strong and Steady 60+: strength and balance work for adults 60 and over.
• CrossFit Classes: coached group training, scaled every session.
• At Home Kettlebell and At Home Prehab: part of nutrition coaching, for training at home.

The goal is a body that lets you play with your grandkids, go hiking with friends, and carry what life hands you.

Eating enough protein when you are barely hungry

How much protein

Aim for about 1.0 to 1.6 grams of protein per kilogram of body weight a day. JAMA Internal Medicine suggests 1.0 to 1.5 g/kg if you are moderately active. The joint advisory proposes 1.2 to 1.6 g/kg during weight loss, a simple target of 80 to 120 grams a day, or 1.5 grams per kilogram of lean mass when you have a body composition scan. That last option is where an InBody scan helps, because it gives you the lean mass number.

Worked example. The member on tirzepatide in our results below had 153.7 lb of lean body mass on her November 5, 2026 scan. Divide by 2.2 to get about 69.9 kg. Multiply by 1.5, and her target comes to about 105 grams of protein a day, inside the 80 to 120 gram range.

More on daily targets: protein on a GLP-1 and for active adults.

Protein first, smaller meals, shakes that count

Start each meal with 20 to 30 grams of protein, then eat the rest of the plate. Smaller, more frequent meals are easier than three big ones when you fill up fast. If a drink is all you can manage, use a shake with at least 20 grams of protein. Easy foods on low-appetite days:

• Greek yogurt
• Cottage cheese
• Eggs
• Fish and chicken
• Beans
• Soups and smoothies

Fluids, fiber and side effects

Drink 2 to 3 liters of fluid a day, per JAMA Internal Medicine. Add fiber from vegetables, fruit, beans and whole grains to help with constipation. Smaller portions help with nausea. Talk with your prescriber about supplements and about any side effect that keeps you from eating.

Built around the foods you already eat

Your plan starts with the foods you already eat. Your coach swaps a few items for higher protein versions, scales portions to your appetite, builds simple plates you can repeat, and adjusts every week based on how you are eating, training and feeling. When the dose changes, the plan changes with it.

Measure what you are losing: InBody scans

The way to know you are losing fat and keeping muscle is to measure it. An InBody scan reports skeletal muscle mass, body fat mass and body water, so you can see what the scale cannot. Scan under the same conditions (same time of day, similar food and fluid) about every 4 weeks, and read the trend instead of any single number. Our post on tracking muscle on a GLP-1 with InBody covers how the scan compares with DXA. The member results below come straight from those scans.

How GLP-1 nutrition coaching works at CrossFit Cerberus

Cerberus Nutrition is one-on-one coaching, open to members and non-members. Here is how it runs:

1. Free Nutrition Strategy Session. Thirty minutes with your coach to go over your goals, how you eat now, what has not worked before, and what coaching would look like for you. You leave with a kickoff plan built around your food.
2. Map your starting point. Including an InBody scan of your muscle and fat.
3. Your plan, built around foods you already eat. Protein targets and plate builds that fit your appetite.
4. Weekly check-ins and adjustments. Dose changes and low-appetite weeks get handled as they come.
5. Coached strength training if you want it. In the gym or at home.

You can bring your InBody reports to your prescriber appointments, so everyone working with you sees the same numbers.

At Home Kettlebell and At Home Prehab are part of nutrition coaching

Two at-home programs come with nutrition coaching: At Home Kettlebell and At Home Prehab. They are how you protect muscle while you are on a GLP-1 or coming off one, and how you build confidence before you lift in the gym. Stacy Banwell and Janelle Stahl both use them.

Your nutrition coaches:

• Carl Neidholdt: Precision Nutrition Level 2, CrossFit Level 2
• Jackson Finkeldei: Precision Nutrition Level 1
• Brook Fish: Precision Nutrition Level 1, NASM Nutrition
• Candace Logan: Nutrition Coach
• Bri Clausen: Nutrition Coach

Planning for a lower dose or stopping

Plan for a lower dose or a stop before it comes. The joint advisory reports that up to two-thirds of lost weight is regained within a year of stopping, and that 50% to 67% of people stop within a year. JAMA Internal Medicine gives the guidance for keeping weight off: keep resistance training 2 to 3 times a week, keep protein up, and stay active.

Anxious about life after you stop your GLP-1s? Will the weight just come back? As appetite returns, your coach raises food in steps, keeps protein high, and watches the InBody trend so muscle stays and fat stays off. Your prescriber decides your dose. Coaching builds the habits and the strength that hold your results either way.

Two members below show what that looks like. Stacy Banwell's doctor took her off Mounjaro because she no longer needed it to manage her diabetes. Janelle Stahl came off her GLP-1, raised her protein, and rebuilt muscle with At Home Kettlebell and At Home Prehab.

Results from Cerberus members on GLP-1s

Every number here comes from InBody scans and training logs at Cerberus.

Stacy Banwell: off Mounjaro, fat down, muscle up

Stacy Banwell started Cerberus nutrition coaching while on Mounjaro. Her doctor took her off Mounjaro because she no longer needed it to manage her diabetes. She has been working hard through health challenges, and her InBody scans show it:

• Weight: 269.4 lb to 235.7 lb
• Fat: 139.1 lb to 102.9 lb (down 36.2 lb)
• Skeletal muscle: 71.7 lb to 76.1 lb (up 4.4 lb)
• Body fat: 51.6% to 43.1%

She trains with At Home Kettlebell and At Home Prehab. In her lift log she went from a 15 lb technique bar to a clean and jerk of 40 and a snatch of 25, then a front squat of 5x5 at 45. In her words: “I would have never thought I could carry a 50 pound box downstairs.”

Janelle Stahl: coming off a GLP-1 and rebuilding muscle

Janelle Stahl came off her GLP-1 around September 7, 2026. While she was on it, her protein averaged about 25 to 30 grams a day and her calories about 537 to 544 a day. After she came off, her protein rose to about 120 to 128 grams a day and her calories to about 1,251 to 1,287.

Her skeletal muscle mass went from a low of 59.1 lb to a peak of 64.8 lb, and it is now 61.5 lb, right back at her starting point. She is using At Home Kettlebell and At Home Prehab, part of nutrition coaching, to rebuild muscle and confidence for a return to lifting in the gym.

A member on Ozempic: fat down, muscle up

This member has been on Ozempic, including a full dose in January 2026. InBody scans from July 1, 2025 to September 1, 2026, a window that includes that time on the medication, show:

• Weight: 275.1 lb to 262.7 lb (down 12.4 lb)
• Fat: 114.2 lb to 95.8 lb (down 18.4 lb)
• Skeletal muscle: 90.2 lb to 93.5 lb (up 3.3 lb)
• Body fat: 41.5% to 36.5%

The scale moved 12.4 lb. Fat moved 18.4 lb, because muscle went up. On eating enough while appetite was low, this member said: “I'm stuffing myself anyway, because I need to do the muscle thing.”

A member on tirzepatide: 42 lb down, about 82% of it fat

In a November 20, 2025 session, this member said she had been on “that medicine before” without lifestyle changes, and Carl told her, “I don't see a need for it yet.” On April 23, 2026 she started tirzepatide at 2.5 mg, this time alongside Cerberus coaching. From that start scan to November 5, 2026:

• Weight: 284.1 lb to 242.1 lb (down 42.0 lb)
• Fat: 123.0 lb to 88.5 lb (down 34.5 lb, about 82% of the loss)
• Skeletal muscle: 90.6 lb to 86.4 lb (down 4.2 lb)
• Body fat: 43.2% to 36.5%
• Lean body mass: 161.2 lb to 153.7 lb
• Visceral fat: 23 to 18

On October 8, 2026 she said, “while I do have about the same amount of muscle, like my body is smaller than it was three months ago.” Her scans show skeletal muscle down 4.2 lb over the run, a small share of a 42 lb loss.

She held her strength through the loss. Her April 25 powerlifting total was squat 250, bench 165 and deadlift 345. Her July 27 CrossFit total was back squat 255, strict press 105 and deadlift 320. Her current maxes are back squat 255 and deadlift 325. Her squat held and her deadlift came down a little while she lost 42 lb.

Same pattern as T-REx: lift and eat enough protein, and most of what comes off is fat.

Questions

How do I keep my muscle on Ozempic, Wegovy, Zepbound or Mounjaro?

Lift weights two to three times a week and eat protein first at every meal. In the T-REx trial published in Nature Medicine in November 2026, adults aged 50 to 70 on tirzepatide who did three supervised strength sessions a week lost the same weight as those who did not train, lost less lean tissue (3.57 kg vs 4.67 kg), and got 10% to 18% stronger, while the group that did not train got 6% to 9% weaker. At CrossFit Cerberus in Blue Springs, a member on Ozempic lost 18.4 lb of fat and added 3.3 lb of skeletal muscle between July 1, 2025 and September 1, 2026, and a member on tirzepatide lost 42 lb, about 82% of it fat, after starting the medication at 2.5 mg on April 23, 2026 alongside coaching. She kept her back squat at 255 while skeletal muscle dipped 4.2 lb. Stacy Banwell has been working hard through health challenges. She started nutrition coaching while on Mounjaro, and her doctor took her off Mounjaro because she no longer needed it to manage her diabetes. Her InBody scans show weight from 269.4 lb to 235.7 lb, fat down 36.2 lb, and skeletal muscle up 4.4 lb. We pair coached strength training and one-on-one nutrition coaching, including At Home Kettlebell and At Home Prehab, with InBody scans so you can see that the weight coming off is fat.

How much of the weight I lose on a GLP-1 is muscle?

Without structured strength training, a large share of the loss can be lean tissue. In the STEP 1 trial, as reported in the 2025 joint advisory, 38% of the weight lost was lean mass, and the authors put muscle at about 20% of the loss. That split is not fixed. A Cerberus member on tirzepatide lost 42 lb from April 23, 2026 to November 5, 2026, and about 82% of that loss was fat (34.5 lb of fat). Skeletal muscle dipped 4.2 lb, from 90.6 lb to 86.4 lb. An InBody scan is how you check your own numbers.

How much protein do I need on a GLP-1?

Guidance for people on a GLP-1 runs from about 1.0 to 1.6 grams of protein per kilogram of body weight a day, and JAMA Internal Medicine suggests starting each meal with 20 to 30 grams. A 2025 joint advisory from four obesity and nutrition societies also offers a simple target of 80 to 120 grams a day, or 1.5 grams per kilogram of lean mass if you have a body composition scan. Your InBody scan at CrossFit Cerberus gives us that lean mass number, and your coach builds the target around foods you already eat. Janelle Stahl is one example of why the target matters: while she was on a GLP-1, her protein averaged about 25 to 30 grams a day. After she came off, it rose to about 120 to 128 grams a day, and her skeletal muscle mass went from a low of 59.1 lb to a peak of 64.8 lb. It is now 61.5 lb.

How often should I strength train on a GLP-1, and what kind?

Plan on two to three coached strength sessions a week. JAMA Internal Medicine recommends 2 to 3 sessions a week for about 30 minutes, and the 2025 joint advisory recommends at least 3, plus at least 150 minutes of walking or other moderate cardio. Cover squats, hinges, pushes, pulls and carries, and let the load go up over time. At Cerberus that can happen in the gym or at home. Stacy Banwell uses At Home Kettlebell and At Home Prehab, which are part of nutrition coaching, and her lift log shows a 15 lb technique bar, a clean and jerk of 40 and a snatch of 25, and a front squat of 5x5 at 45.

Can I start lifting if I have never trained, am over 50, or have achy joints?

Yes. Cerberus scales the work through the Start Here Workshop, Personal Training, Strong and Steady 60+, CrossFit Classes, and, as part of nutrition coaching, At Home Kettlebell and At Home Prehab. Janelle Stahl is using those at-home programs to rebuild muscle and confidence for a return to lifting in the gym. Stacy Banwell started with a 15 lb technique bar and progressed to a front squat of 5x5 at 45.

Is nutrition coaching worth it if I am already on a GLP-1?

Yes, because the medication lowers your appetite but does not plan your meals, protect your muscle, or build the habits that hold your results when the dose changes. The 2025 joint advisory reports that up to two-thirds of lost weight is regained within a year of stopping, and it calls for nutrition support alongside the medication. Stacy Banwell started nutrition coaching while on Mounjaro. Her doctor took her off Mounjaro because she no longer needed it to manage her diabetes. She has been working hard through health challenges, and her InBody scans show weight from 269.4 lb to 235.7 lb, fat down 36.2 lb, and skeletal muscle up 4.4 lb. Janelle Stahl came off her GLP-1 around September 7, 2026, raised her protein from about 25 to 30 grams a day to about 120 to 128 grams, and rebuilt muscle. Coaching is open to members and non-members. Start with a free Nutrition Strategy Session at (816) 441-4426.

How do I know I am losing fat and not muscle?

Use a body composition scan, not just the scale. At CrossFit Cerberus that is an InBody scan, taken under similar conditions and read as a trend. A member on Ozempic showed fat down 18.4 lb and skeletal muscle up 3.3 lb from July 1, 2025 to September 1, 2026. A member on tirzepatide lost 42 lb from April 23, 2026 to November 5, 2026, with about 82% of that loss from fat, while skeletal muscle dipped 4.2 lb. On October 8, 2026 she said, “while I do have about the same amount of muscle, like my body is smaller than it was three months ago.” Stacy Banwell's scans show fat down 36.2 lb (139.1 lb to 102.9 lb) and skeletal muscle up 4.4 lb (71.7 lb to 76.1 lb).

What happens if I lower my dose or stop, and how do I keep the weight off?

The 2025 joint advisory reports that up to two-thirds of lost weight is regained within a year of stopping. JAMA Internal Medicine's guidance is to keep resistance training two to three times a week, keep protein up, and stay active. Stacy Banwell's doctor took her off Mounjaro because she no longer needed it to manage her diabetes, and she continues At Home Kettlebell and At Home Prehab. Janelle Stahl came off her GLP-1 in September 2026 and used higher protein plus those same at-home programs to rebuild muscle and get ready to lift in the gym again.

Do I have to be a gym member to get nutrition coaching?

No. Cerberus Nutrition is open to members and non-members. At Home Kettlebell and At Home Prehab are part of nutrition coaching, so you can protect muscle while you are on a GLP-1, or coming off one, and build confidence before you lift in the gym. Start with a free Nutrition Strategy Session.

Book your free Nutrition Strategy Session

Thirty minutes with your coach, at no cost. You leave with a kickoff plan built around your food.

Book your free Nutrition Strategy Session or call (816) 441-4426.

CrossFit Cerberus, 200 NW 11th Street, Blue Springs, MO 64015, across from City Hall in the old post office building. Location and directions. Contact us.

Sources

• Joint advisory on nutrition and GLP-1 therapy (2025), PMC12612741
• JAMA Internal Medicine Patient Page: I Am Taking a GLP-1 Weight-Loss Medication: What Should I Know?
• Nature Medicine (2026): Resistance exercise to attenuate lean mass loss during tirzepatide therapy for obesity (T-REx)
• University of Western Australia news release on the T-REx trial (November 2026)
• Cleveland Clinic: Can Ozempic Cause You To Lose Muscle?
• Cleveland Clinic: Taking GLP-1s? Make Sure You Exercise