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Guide · Updated April 2026

The Best Workout Routine for GLP-1 Users Who Want to Keep Muscle

The best workout routine for GLP-1 users centers on heavy resistance training 3 to 4 days per week, 0.8 to 1.0 grams of protein per pound of goal body weight, and limited steady-state cardio. SURMOUNT-1 data showed roughly 34% of tirzepatide weight loss came from lean mass without targeted training.

My first DEXA scan on Mounjaro came back three months after I started 2.5 mg. I had lost 22 pounds. Of those 22, about 7 pounds were lean mass. That is a 32% lean mass share, almost exactly what the published trial data predicts for tirzepatide. The scary part is how little I felt it happen. My clothes fit better. My lifts were the same-ish. The scale was doing what I wanted. The scan told a different story.

This guide is the training protocol I rebuilt after that scan, and what the research says about the best workout routine for GLP-1 users. The drugs in question are tirzepatide (sold as Mounjaro for diabetes and Zepbound for weight loss) and semaglutide (Ozempic for diabetes, Wegovy for weight loss). Both are GLP-1 receptor agonists. They slow gastric emptying, reduce appetite at the hypothalamus, and lower blood glucose. They do not preserve muscle. That job is yours, and training is how you do it.

Why GLP-1 users lose muscle without a plan

The headline numbers from the SURMOUNT-1 trial (NEJM, July 2022) look great. Participants on 15 mg tirzepatide lost 22.5% of body weight over 72 weeks. What the body composition substudy (Neeland, Diabetes Obesity and Metabolism, 2024) added is the split. Fat mass dropped 33.9%. Lean mass dropped 10.9%. Net ratio improved. But 10.9% of your muscle, tendon, organ, and bone mass is a real cost.

Semaglutide looks worse on this metric. In STEP 1 (NEJM, Feb 2021) the lean mass share of total weight lost ran 39 to 45% depending on the subgroup. Tirzepatide is not magic, it just loses more fat alongside, which dilutes the percentage. The absolute lean mass loss is similar or worse on both drugs than standard caloric restriction.

Three things drive the muscle loss:

You control two of those three. That is the whole game.

The 4-pillar framework

The best workout routine for GLP-1 users is not one routine. It is four rules that shape any routine you pick.

  1. Resistance training is the anchor. 3 to 4 sessions per week, hitting every major muscle group twice.
  2. Heavy loads, moderate reps. Most working sets in the 5 to 10 rep range. Train close to failure.
  3. Cardio is a side dish, not the main meal. 1 to 2 short sessions per week. Zone 2 or intervals, not slow-burn hour-long treadmill blocks.
  4. Eat enough protein to justify the training. 0.8 to 1.0 g per pound of goal body weight, every day.

Drop any one of these and the other three will not save you. I tried running 4 days a week and lifting twice during month 2. My next scan showed another 3 pounds of lean mass gone. Cardio on top of a GLP-1 deficit is how you end up skinny-fat.

Training split: the 3-day and 4-day options

Pick one of these. Run it for at least 8 weeks before changing.

3-day full body (for people with less time)

Each session: 5 to 6 exercises, 3 sets of 6 to 10 reps. 45 to 60 minutes total.

4-day upper/lower (my current split)

Each session: 5 to 7 exercises, 3 to 4 sets of 5 to 10 reps. 60 to 75 minutes.

I moved from 3-day full body to 4-day upper/lower at month 4 when my sessions started running long. The 4-day split lets you hit each lift with more volume and fresher. If you are new to lifting, start with 3-day full body. You will progress faster.

More detail on splits and progression is in the GLP-1 Muscle Preservation Protocol, which breaks down the science of why heavy lifting beats circuit training for lean mass retention on these drugs.

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Sample weekly routine (4-day upper/lower)

This is what I run now, month 14 on Mounjaro at 10 mg.

Monday, Lower A

Tuesday, Upper A

Thursday, Lower B

Friday, Upper B

Saturday, optional cardio

That is the whole week. Five to six hours of training. Nothing fancy.

Comparison: workout styles for GLP-1 users

StyleMuscle retentionCalorie burnGLP-1 fitNotes
Heavy resistance (5-10 reps)ExcellentModerateStrong fitBest for lean mass. Manageable fatigue.
High-rep circuit trainingPoorHighWeak fitFeels hard, spares little muscle.
CrossFit / metconsFairHighMixedFun, but high fatigue on a deficit.
Pilates / yogaPoor for muscle retentionLowSupplement onlyGreat mobility work. Not enough stimulus.
Long steady-state cardio (60+ min)PoorHighWeak fitAccelerates lean mass loss on a deficit.
Zone 2 cardio (30-40 min, 1-2x/wk)NeutralModerateStrong fitSupports recovery and heart health.
HIIT (15-20 min, 1x/wk)NeutralHigh per minuteStrong fitShort, sharp, low lean mass cost.

The takeaway is that heavy resistance training is the only style that actively defends lean mass. Everything else either supports it or competes with it for recovery.

Progressive overload on reduced calories

Here is where GLP-1 training differs from a normal cutting phase. Your calories are low. Your recovery is slower. Progress looks different.

What progressive overload means now:

What it does not mean:

I kept a training log from day one. Month 1, my squat was 245 for 5. Month 14, it is 265 for 5. That is a 20-pound gain on a 22% body weight cut. On paper it looks like stagnation. For someone in a deep caloric deficit, it is a win. My DEXA shows I held lean mass from month 6 forward. The numbers move slower, but they move.

Cardio rules for GLP-1 users

Cardio on a GLP-1 is a trap. It feels productive. The scale rewards it. Your DEXA will not.

Do:

Do not:

The GLP-1 and Exercise: Build Muscle on GLP-1s guide goes deeper on the cardio trade-off and why most GLP-1 influencers get this wrong. The short version is that every hour of cardio on a deep deficit is an hour your body spends pulling amino acids out of muscle tissue to keep you moving.

Nutrition that actually supports the training

Training without eating enough is decorative. You will feel like you did something. Your body will still cut muscle. The non-negotiables:

Protein target: 0.8 to 1.0 grams per pound of goal body weight. If your goal weight is 170, that is 136 to 170 g of protein per day. This is hard on a GLP-1. Appetite is flat. Meat feels heavy. The fix is front-loading protein at breakfast and using whey isolate shakes as a tool, not a treat. Full breakdown in How Much Protein You Need on a GLP-1.

Calories: Do not voluntarily stack deeper deficits on top of what the drug already creates. If you are losing more than 1% of body weight per week, eat more. Faster loss means more muscle loss, full stop.

Creatine: 3 to 5 g per day, every day. Cheapest and most-researched muscle retention tool you have. I cover the GLP-1 specifics in Creatine on Ozempic and Mounjaro.

Timing: Get 30 to 40 g of protein within 90 minutes of your training session. This is not bro-science. In a deficit, the anabolic signal is weaker, and you want to stack every advantage.

My typical training-day food log is in What I Eat in a Day on Mounjaro. Appetite suppression is real and it is what makes protein the hardest nutrient to hit.

Recovery: the underrated variable

A GLP-1 deficit shortens your recovery budget. A session that would have felt like a 6 off the drug feels like an 8 on it. That is not weakness. That is reduced glycogen, reduced calorie input, and sometimes reduced sleep from side effects.

Signs you are under-recovering:

The fix is usually simple. Take an extra rest day. Eat 200 more calories, mostly carbs, on training days. Sleep 30 more minutes. Cut a cardio session. Do not add more training volume to fix a recovery problem.

The mistakes I see most often

These are the patterns I see on Reddit and in DMs that wreck GLP-1 body composition outcomes.

Mistake 1: Treating GLP-1s as a substitute for training. The drug drops weight. It does not build or protect muscle. A scale dropping fast is not progress if 40% of it is lean mass.

Mistake 2: Switching to high-rep “toning” workouts. Light weights for 15 to 20 reps feel appropriate for the lower energy of a GLP-1, but they do not preserve lean mass well. Heavy and short beats light and long.

Mistake 3: Running marathons on 1,200 calories. I watched a friend do exactly this. She lost 60 pounds on Wegovy in 10 months. She also lost most of her glutes and hamstrings. Her follow-up DEXA was brutal.

Mistake 4: Ignoring the scale entirely. The opposite trap. If you are losing more than 1.5 to 2 pounds per week consistently, you are losing muscle you did not have to lose. A DEXA every 3 to 6 months catches this. My process for reading one is in DEXA Scan After 6 Months on Mounjaro.

Mistake 5: Training hungover on side effects. First 2 to 3 days after a dose is often the worst for nausea. If you train those days, scale intensity back 20 to 30%. Do not try to hit a PR on a day you can barely keep water down. More on managing this in How to Manage Nausea on Mounjaro.

What changes in maintenance

When you hit goal weight or move to a maintenance dose, training shifts. Calories come up. Recovery gets easier. You can add volume, not just hold it.

In maintenance I added a 5th session (arms and accessories). I also added a second cardio day. The reason you could not do this during active loss is the same reason you can now: calorie availability. More fuel, more training. My current split and maintenance adjustments are in the GLP-1 Maintenance Guide.

Equipment and gym choices

You do not need a fancy gym. You do need:

A Planet Fitness membership will work for most of this. The one exception is squatting, where the Smith machines are a poor substitute. If you can only go one direction, get access to a real squat rack somewhere. Garage gyms, small commercial gyms, and YMCAs usually have them.

Bottom line

The best workout routine for GLP-1 users is 3 to 4 days of heavy resistance training, 1 to 2 short cardio sessions, and a hard daily floor of 0.8 to 1.0 g of protein per pound of goal body weight. Lift heavy, eat enough protein, keep cardio modest, and do not chase the scale faster than 1% per week. That is the protocol that held my lean mass flat from month 6 through month 14 on Mounjaro. It will not optimize for the fastest scale drop. It will optimize for the body you actually want at the end.

If you want to model your own lean mass trajectory, the Body Composition Calculator estimates fat vs lean mass changes based on your weight loss rate. Pair it with the GLP-1 Body Composition Guide for the full framework.

FAQ

Can I keep all my muscle on a GLP-1?

Probably not all of it, but you can get close. Published trial data shows untrained GLP-1 users lose 10 to 15% of their lean mass on average. With heavy resistance training, adequate protein, and moderate cardio, I held my lean mass roughly flat from month 6 to month 14. My total lean mass is about 4 pounds below where I started, against 68 pounds of weight loss.

How many days per week should I lift on Ozempic or Mounjaro?

Three days per week is the minimum to see real lean mass retention, and four is the sweet spot for most people. Five or more days usually backfires because recovery is compromised on a GLP-1 deficit. Pick a split you can run consistently for 8 weeks without missing more than one session.

Should I do cardio or lift first?

If you do them on the same day, lift first. Cardio before lifting blunts strength output by 10 to 20% and makes muscle retention harder. Better solution: put cardio on a different day or at the opposite end of the day from your lifting session.

Is HIIT bad on a GLP-1?

No. One short HIIT session per week (15 to 20 minutes) is a reasonable addition for heart health and calorie flexibility. The issue is not HIIT itself, it is stacking 3 to 4 HIIT sessions on top of lifting and a deep caloric deficit. Your recovery budget cannot cover that.

What if I have never lifted weights before?

Start with the 3-day full body split at the weights you can control with good form. Do not load until you can complete every set with clean reps. A month of light sets beats a week of heavy sets with a back tweak that sidelines you. If you can afford it, 4 to 6 sessions with a trainer to learn the squat, deadlift, bench, and overhead press pays back forever.

Do I need supplements beyond protein?

Creatine (3 to 5 g per day), vitamin D (1,000 to 2,000 IU per day if you are deficient), and possibly magnesium for sleep. That is it for muscle retention. Everything else is marginal. The full list of what is actually worth taking is in Best Supplements on GLP-1s (DEXA Tested).

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