I spent the first two months on GLP-1 doing what I always did when I was trying to lose weight: pushing through workouts I didn’t have the energy for, walking every day regardless of how I felt, and wondering why I was wiped out by 3 PM.
The medication was working. The scale was moving. But my energy was lower than I expected, and I couldn’t figure out if that was normal or if I was doing something wrong.
It was mostly normal. And once I understood why, I stopped fighting my body and started working with it.
Here’s what I’ve learned about exercise on GLP-1 after 14 months: what the research shows, what my provider told me, and what actually made a difference.
Why Exercise Matters More on GLP-1 Than Off It
GLP-1 medications work by reducing appetite and slowing digestion. You eat less. You lose weight. That’s the point.
The problem is that when you lose weight quickly, you don’t lose only fat. You also lose some muscle. And muscle is what keeps your metabolism working, your joints stable, and your energy levels consistent as you age.
Research on GLP-1 medications has consistently shown that without intentional resistance training, a meaningful portion of the weight lost on these drugs comes from lean muscle mass. One frequently cited figure is that roughly 25 to 40 percent of total weight lost on GLP-1 may be muscle rather than fat, depending on diet and activity level.
That’s not a reason to avoid GLP-1. It’s a reason to take exercise seriously while you’re on it.
The goal isn’t to burn more calories. The goal is to protect what you already have.
The Fatigue Problem
When you’re eating significantly less — which most people do on GLP-1 — your body has less fuel available. Intense workouts pull from that limited pool. You finish a session and you’re not just tired; you’re depleted in a way that takes days to recover from.
I made this mistake in month two. I was feeling good, the nausea had settled, and I tried to add back the cardio routine I’d done before. Three sessions in, I could barely get through a workday. My provider explained that the combination of reduced caloric intake and the medication’s effect on digestion meant I simply didn’t have the energy reserves to sustain that level of output.
The fix was not to push through. It was to change what I was doing.
What Actually Works: The Order of Priority
1. Walking First
Walking is the single most underrated exercise for people on GLP-1, and it was the first thing my provider recommended. Not because it burns the most calories, but because it’s sustainable at low energy levels, it improves insulin sensitivity, and it keeps the body moving without creating a recovery deficit.
I aim for 7,000 to 10,000 steps a day. On days when I’m tired, I walk 20 minutes after dinner instead of skipping entirely. That counts.
2. Strength Training Two to Three Times a Week
This is the most important thing you can do to protect muscle on GLP-1. You do not need a gym. You do not need heavy weights. Bodyweight exercises, resistance bands, and light dumbbells are enough to send the signal your body needs to hold onto muscle tissue while losing fat.
I do two to three sessions a week, 30 to 40 minutes each. The sessions are not intense by any prior standard. Squats, lunges, rows, pushups, and core work. The consistency matters more than the difficulty.
If you’re looking for a structured program that doesn’t require equipment or a gym, the home workout options I cover here are worth reading — especially if you or your partner are a man over 40 looking for something specifically designed for that stage of life.
3. Creatine
I added creatine three months into GLP-1. My provider suggested it as a way to support muscle retention when protein intake and caloric intake are both reduced. Creatine helps muscles recover, supports strength output, and has a solid safety record for long-term use.
I use Arq8 FullDissolve creatine. It’s a nanoscale creatine that absorbs faster than standard powder and doesn’t require loading. I take it daily regardless of whether I work out that day. You can find what I use here.
Affiliate link — I may earn a commission at no extra cost to you.
4. Cardio as an Add-On, Not the Foundation
Moderate cardio — cycling, swimming, elliptical — is fine to include once you’ve established the walking and strength training habits and your energy has stabilized. It’s not where I’d start, and it’s not what I’d prioritize if energy is limited.
High-intensity cardio (running, HIIT at real intensity) can be added after several months when your body has adapted to the medication and your muscle base is protected. I do some of this now. I didn’t touch it until month eight.
How Much Exercise Is Enough
For muscle retention on GLP-1, the minimum that shows results in research is two strength sessions per week. That’s a very achievable target.
If you’re doing two strength sessions and walking daily, you are doing enough. Adding more is fine if energy allows. Doing less means you’re likely losing more muscle than you need to.
The standard recommendation of 150 minutes of moderate activity per week still applies here — but the composition of that activity matters more on GLP-1 than it does for general health. Prioritize resistance. Let the cardio fill in around it.
What to Eat Around Workouts
Protein is the main lever. GLP-1 reduces appetite, which means most people inadvertently reduce protein intake along with everything else. Protein is what your muscles use to repair and rebuild after training.
My target is 100 to 120 grams of protein per day. On a reduced-appetite diet, that requires intentional planning. I eat protein first at every meal. I use a protein shake after strength sessions when I’m not hungry enough for a full meal.
If you’re not tracking protein, start there before worrying about macros, timing, or supplements.
What Doesn’t Work
Exercising through exhaustion. If you are genuinely fatigued from the medication, more exercise will not help. It will set you back. Rest when you need to rest.
Cardio as the primary strategy. Cardio burns calories. On GLP-1, the medication handles appetite and caloric reduction. You do not need to add a significant cardio load on top of that. What you need is to protect the muscle you’re at risk of losing.
Skipping exercise entirely because you feel sick in the first weeks. The first four weeks on a new dose are the roughest. Walking is almost always manageable even when other exercise isn’t. Start there and come back to the rest when the nausea settles.
The Bottom Line
Exercise on GLP-1 is not optional if you care about what your body looks like and how it functions after you reach your goal weight. The medication does the hard work on appetite. Your job is to make sure what you lose is fat, not muscle.
Two strength sessions a week, daily walking, adequate protein, and creatine. That is the framework. Everything else is detail.
If you haven’t started GLP-1 yet and want to understand your options, the program I use is through ShedRX. They offer GLP-1 microdosing through telehealth at $200 to $400 a month, significantly less than brand-name costs. You can see the details here.
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