If you're taking Mounjaro or Wegovy, you may have been advised to prioritise resistance training while on GLP-1 medications. This is a sound recommendation. If your muscles aren't getting enough stimuli, you can end up losing a greater proportion of lean muscle mass compared to fat tissue.
The reassuring part is that you don't need years of gym experience to protect your muscle. This guide covers how much resistance training the evidence actually supports, which type of training suits beginners, how to structure your first few weeks, and how to work around common side effects like nausea and fatigue.
Why resistance training matters on GLP-1 medications
Mounjaro (tirzepatide) and Wegovy (semaglutide) work by mimicking gut hormones that signal fullness to the brain and slow the rate at which the stomach empties, which is why appetite and portion sizes drop so noticeably in the first few months of treatment. Eating less inevitably creates a calorie deficit, and in any calorie deficit the body draws energy from both fat stores and muscle tissue unless it's given a reason to hold onto the muscle.
A dual-energy X-ray absorptiometry (DXA) substudy of the SURMOUNT-1 trial found that around 75% of the weight lost on tirzepatide came from fat mass, with roughly 25% from lean mass - a ratio broadly similar to weight lost through diet alone.1 This means there wasn't a significant difference in the proportion of fat lost compared to muscle for people taking GLP-1 medication vs. people losing weight on diet alone. While this is reassuring, the study also showed that resistance training is the most effective way to shift that ratio further in favour of fat loss - by giving your muscles a reason to adapt rather than simply shrink.
There are also longer-term benefits to maintaining as much muscle as possible while losing weight such as keeping your basal metabolic rate (BMR) higher, meaning your body burns more calories while resting. This helps support continued weight loss while you're taking GLP-1 treatments.
We've covered this in more detail in our article on whether Mounjaro or Wegovy causes muscle loss.
How much resistance training do you actually need?
According to the UK Chief Medical Officers' physical activity guidelines, adults should do activities that work all the major muscle groups (legs, hips, back, abdomen, chest, shoulders and arms) on at least 2 days a week.2 The same guidance specifically notes that GLP-1 weight management medicines are licensed for use alongside physical activity, and flags strengthening work as particularly important for maintaining muscle mass during treatment with these medicines.2
The NHS gives the same 2-day target for muscle-strengthening activity, alongside a separate goal of at least 150 minutes of moderate-intensity activity a week, such as brisk walking, spread across 4 to 5 days.3 For most people starting out on Mounjaro or Wegovy, the strengthening target is the one that matters most for protecting muscle, and it's genuinely achievable. Two sessions a week is enough, even for someone who has never lifted a weight before, and each session doesn't need to last more than 30 to 45 minutes.
Which type of resistance training should you choose?
There's no single correct way to strength train, and the best choice is whichever one you'll actually do consistently.
Bodyweight exercises
Squats, push-ups (including wall or knee variations), lunges and glute bridges require no equipment and can be done at home. They're the natural starting point if you're new to resistance training, as they let you learn the movement pattern before adding load.
Resistance bands
Bands are inexpensive, portable and let you adjust resistance easily by changing the band or your grip. They're a good bridge between bodyweight training and free weights, particularly for upper body and shoulder work.
Free weights
Dumbbells and kettlebells allow more precise progression than bands, since you can increase weight in small, specific increments. If you're new to free weights, start light and focus on controlled movement rather than lifting as much as possible.
Gym machines
Machines guide the movement path for you, which can make them a more confidence-inspiring option if you feel unsteady with free weights. Most gyms offer a free induction session, which is worth taking if you've never used resistance machines before.
Getting started as a complete beginner
Start with movements that use your own bodyweight before adding external load. This lets you learn the pattern of a squat, a push and a hinge without worrying about how much weight you're lifting.
A simple beginner structure can look something like this:
- Weeks 1 to 2 - bodyweight squats, wall or knee push-ups, and glute bridges, 2 sets of 8 to 12 repetitions
- Weeks 3 to 4 - add a resistance band or a light pair of dumbbells to the same movements, still 2 to 3 sets
- Weeks 5 onwards - increase the weight gradually once you can complete all sets and repetitions with good form - this is known as "progressive overload"
Rest for at least 48 hours between sessions that target the same muscle group, and don't be discouraged if strength gains feel slow in the first month. Adapting to a new type of exercise while your body is also adjusting to a new medication takes time, and consistency matters far more than intensity in the early weeks.
A short warm-up of 5 minutes of light movement, such as marching on the spot or gentle arm circles, helps prepare your joints and reduces the chance of straining a muscle before it's used to load. Focus on moving through the full range of each exercise with control rather than rushing the repetition, and stop a set if your form starts to break down rather than pushing through to a fixed number. A repetition performed with poor technique doesn't build strength any faster, and it increases the risk of injury.
Pairing your training with enough protein gives your muscles the raw material they need to respond to the stimulus, so you should consider both together rather than focusing on exercise alone.
How does resistance training fit alongside cardio?
Resistance training and aerobic activity, such as walking, cycling or swimming, do different jobs. Aerobic exercise burns calories during the activity itself and supports heart and lung health, while resistance training is what signals to your body that muscle is worth keeping even as you lose weight. Neither replaces the other, and the NHS guidance covers both because they work best together.3
If you're new to exercise altogether, it's reasonable to introduce them gradually rather than trying to meet both targets in your first week. Many people find it easier to build a walking habit first, since it requires no equipment or technique, and then layer in 2 resistance sessions once that feels manageable. There's no strict order you have to follow. What matters is that both are in place within your first month or two of starting a GLP-1 medication, since this is when the risk of losing muscle alongside fat is highest.
Managing training around side effects
The most commonly reported side effects of GLP-1 medications are gastrointestinal, and they can make a session feel harder than it should:
- Nausea - very common, especially in the first few weeks after a dose increase. Training earlier in the day, before symptoms build, and keeping sessions shorter until it settles can help.4
- Fatigue - common, particularly around dose titration. Lower the intensity rather than skipping the session altogether where possible.
- Reduced appetite before training - a small, easily digested snack such as a banana or plain toast 30 to 60 minutes beforehand can help if training on an empty stomach leaves you lightheaded.
- Dehydration - reduced fluid intake alongside gastrointestinal side effects can affect performance and recovery. Sip water throughout the session rather than drinking a large amount at once.
- Injection site soreness - if you inject into your thigh or abdomen, a session that heavily loads that area on the same day can feel uncomfortable. Either train a different muscle group that day or rotate your injection site away from the area you plan to train.
If nausea or fatigue is severe enough to stop you training altogether, this is worth raising with your prescriber. It may point to a dose that needs more time to settle, or a titration schedule moving faster than your body can adapt to.
When should you seek medical advice?
Speak to your prescriber or GP if:
- You feel persistently weak or unusually breathless during light activity
- You experience dizziness or fainting during or after exercise
- Nausea, vomiting or diarrhoea are severe enough to affect your ability to eat or drink normally
- You notice a rapid or unexplained drop in strength alongside your weight loss
Frequently Asked Questions
How many days a week should you do resistance training on Mounjaro or Wegovy?
NHS general guidance recommends muscle-strengthening activity at least 2 days a week for all adults. A 2025 clinical advisory on GLP-1 nutrition support suggests building towards 3 sessions a week specifically to help protect muscle during rapid weight loss. Starting with 2 sessions and adding a third once that feels manageable is a sensible approach.
Can beginners do resistance training without a gym?
Yes. Bodyweight exercises such as squats, push-ups, and planks, combined with resistance bands, can build meaningful strength without any gym equipment. A gym or free weights become more useful once bodyweight exercises start to feel too easy.
Is it safe to start resistance training if you feel nauseous on Mounjaro or Wegovy?
Light to moderate activity is usually fine, but it's sensible to lower intensity or shorten sessions in the days following a dose increase, when nausea and fatigue tend to be strongest. If symptoms are severe or last more than a week or two, speak to your prescriber.
How long before you see results from resistance training on GLP-1 medication?
Early strength gains often come from improved coordination and nervous system adaptation rather than visible muscle change, so noticeable results can take several weeks to a few months. Consistency matters more than the intensity of any single session.
Do you need to lift heavy weights to protect muscle on Wegovy or Mounjaro?
No. Bodyweight and light to moderate resistance, done consistently and taken close to muscular fatigue, is enough to signal to your body that muscle is still needed. Heavier lifting can help once you've built a foundation, but it isn't a requirement for beginners.
What happens if you only do cardio and skip resistance training on GLP-1 medication?
You'll likely still lose weight, since Mounjaro and Wegovy work mainly by reducing appetite. Without resistance training, though, a larger share of that weight loss is likely to come from muscle rather than fat.
References
- Look M, et al. Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study of adults with obesity or overweight. Diabetes, Obesity and Metabolism. 2025. dom-pubs.onlinelibrary.wiley.com
- UK Chief Medical Officers. Physical activity guidelines. GOV.UK; 2019. gov.uk
- NHS. Physical activity guidelines for adults aged 19 to 64. NHS; 2021. nhs.uk
- Electronic Medicines Compendium. Mounjaro SmPC; Wegovy SmPC. eMC. medicines.org.uk/emc
This article is intended for informational purposes only and does not replace professional medical advice. Always read the patient information leaflet supplied with your medication and speak to a healthcare professional if you have specific concerns.