Exercise on GLP-1 Medication: A Practical Guide

Exercise is not an optional extra on Mounjaro (tirzepatide), Wegovy (semaglutide) or other GLP-1 medicines. These medicines are licensed for use alongside a reduced-calorie diet and increased physical activity, and regular movement helps protect muscle, supports heart health and mood, and builds habits that matter if you later reduce or stop treatment. For most adults, the target is the UK guideline of 150 minutes of moderate activity a week plus strength work on at least two days. If that sounds a long way off, start small: this guide explains how to begin, what to prioritise, and how to work around low energy and side effects.

Why exercise matters on GLP-1 treatment

It is part of the licence

Both Mounjaro and Wegovy are authorised in the UK for weight management as an adjunct to a reduced-calorie diet and increased physical activity. NICE guidance on overweight and obesity management (NG246) similarly frames medicines as part of a wider approach that includes diet, physical activity and behavioural support. Medication is not meant to work in isolation.

Protecting muscle

When you lose weight, you lose some lean tissue as well as fat. In a body composition substudy of the SURMOUNT-1 trial of tirzepatide, roughly a quarter of weight lost was lean mass. With semaglutide in the STEP 1 trial, the share was higher, closer to two-fifths. That is broadly similar to other forms of calorie restriction, but because GLP-1 medicines can produce large weight losses, the absolute amount can be meaningful.

Strength training, together with adequate protein, is the main tool for limiting muscle loss. We cover the evidence in detail in our guide to preserving muscle mass on GLP-1 treatment.

Benefits beyond the scales

Regular activity has benefits that are independent of weight loss, including:

• better heart and lung fitness
• improved blood pressure, cholesterol and blood sugar control
• stronger bones, which can be affected by significant weight loss
• better mood, sleep and energy levels
• improved balance and mobility, reducing the risk of falls, particularly in older adults
• reduced risk of many long-term conditions

These benefits are a good reason to track more than just your weight. Our guide to measuring progress beyond the scales suggests other markers to watch.

Long-term weight management

Weight regain after stopping GLP-1 medicines is common. A Danish randomised trial published in the New England Journal of Medicine in 2021 looked at adults who had lost weight on a low-calorie diet and were then assigned to exercise, liraglutide, both, or placebo for a year. The combination of exercise and liraglutide maintained the most weight loss and produced the largest improvements in body composition. While this trial used an older GLP-1 medicine, it supports the idea that exercise and medication work well together. See our guide to weight regain after stopping GLP-1 medication.

How much exercise is recommended?

UK guidelines

The UK Chief Medical Officers' Physical Activity Guidelines (2019) recommend that adults:

• do at least 150 minutes of moderate-intensity activity a week (such as brisk walking or cycling), or 75 minutes of vigorous activity (such as running), or a combination
• do muscle-strengthening activities on at least two days a week, working all the major muscle groups
• reduce time spent sitting for long periods
• for older adults, include activities that improve balance and flexibility on at least two days a week

Moderate activity means you are breathing faster and feel warmer, but can still talk. Vigorous activity means you are breathing hard and can only say a few words without pausing.

The 2025 GLP-1 joint advisory

The 2025 joint advisory from four US obesity and nutrition societies recommended regular strength training at least three times weekly plus at least 150 minutes of moderate-intensity aerobic exercise weekly to help preserve muscle and bone during GLP-1 therapy.

If you are starting from very little

These numbers can feel daunting, especially if you have joint pain, low fitness or limited time. The UK guidelines are clear that some activity is better than none, and that even small increases bring benefits. Ten-minute walks, standing up regularly, and a few simple strength exercises at home are all valid starting points.

What type of exercise?

Aerobic (cardiovascular) activity

Activities that raise your heart rate and breathing, done for a sustained period. Good options for people at the start of GLP-1 treatment include:

• walking, gradually increasing pace and distance
• swimming or aqua aerobics, which are gentle on the joints
• cycling, outdoors or on a static bike
• dancing
• using a cross-trainer or rowing machine
• gardening and active housework

Strength (resistance) training

Exercises that make your muscles work against resistance. This could be your body weight, resistance bands, free weights or gym machines. Examples include squats or sit-to-stands, wall or knee press-ups, lunges, step-ups, rows with a band, and carrying shopping. Our step-by-step guide to strength training for beginners on weight loss medication explains how to get started safely.

Balance and flexibility

Yoga, Pilates, tai chi and simple balance exercises improve stability and mobility. They are particularly valuable for older adults and anyone who has lost a lot of weight quickly, as changes in body shape can affect balance.

A sample weekly plan for beginners

The table below shows one way to build up over the first few months. It is a general example, not a personalised programme. Progress at your own pace and repeat a stage if you need to.

Managing energy, side effects and fuelling

Low energy

Many people feel more tired than usual on GLP-1 treatment, especially in the early weeks and after dose increases. Fatigue is often related to eating much less, drinking less and gastrointestinal side effects rather than the medicine directly. Practical tips:

• Eat something before exercise. A small snack an hour or two beforehand, such as a banana with yoghurt, a slice of toast with peanut butter, or a glass of milk, can make a real difference.
• Exercise at the time of day you feel strongest. For some people this is morning; for others, later in the day.
• Keep intensity moderate at first. You can increase it as your body adjusts.
• Plan around your injection. If you feel worse in the day or two after your weekly dose, schedule lighter sessions then.

Nausea and digestive symptoms

Vigorous exercise on a full stomach, or very soon after eating, can worsen nausea or reflux. Leave time after a meal before exercising, and choose lower-impact activities, such as walking or cycling rather than running or jumping, on days when your stomach feels unsettled. If you have vomiting or diarrhoea, rest until you have recovered and rehydrated. Our guide to managing nausea on GLP-1 medication has more tips.

Hydration

Exercise increases fluid loss, and dehydration is already a risk on GLP-1 treatment because of side effects and reduced drinking. Drink before, during and after activity, particularly in hot weather. See our guide to hydration on GLP-1 medication.

Protein and recovery

Muscles need protein to repair and adapt after strength training. Including a source of protein in the meal or snack after exercise, and spreading protein across the day, supports recovery. See our guide to protein intake on weight loss injections.

Dizziness

Dizziness and low blood pressure-related events are listed as common in the Mounjaro product information for weight management. Standing up quickly after floor exercises, exercising when dehydrated, or exercising after eating very little can all bring on light-headedness. Rise slowly, keep fluids up, and stop if you feel faint.

What 150 minutes a week can look like

Meeting the UK guideline does not require long gym sessions. The table below shows a few different ways people might build a week of activity, once they have built up to it.

All of these are valid. The right plan for you is the one you can keep doing.

Common exercise myths on GLP-1 treatment

"The medicine does the work, so exercise doesn't matter"

GLP-1 medicines are licensed to be used alongside physical activity. Exercise contributes to protecting muscle, improving fitness and heart health, and supporting long-term weight management, none of which the medicine can fully provide on its own.

"You need to burn lots of calories for exercise to be worthwhile"

The main benefits of exercise on GLP-1 treatment are not about burning calories. They are about muscle, bone, heart and lung fitness, blood sugar, mood and building sustainable habits. Gentle, regular activity is worthwhile.

"Fasted exercise is better for fat loss"

Exercising on an empty stomach is not necessary, and on GLP-1 treatment, when food intake is already low, it may leave you light-headed or weak. A small snack beforehand is usually more sensible.

"Strength training is only for young people"

Strength training benefits adults of all ages and is arguably most important for older adults, who lose muscle more easily. Exercises can be adapted for any fitness level, including seated options.

"If it doesn't hurt, it doesn't count"

Exercise should feel like effort, but it should not cause sharp pain. Mild muscle soreness a day or two after a new activity is normal; joint pain, chest pain or dizziness are signals to stop.

Exercise and weight-loss plateaus

It is common for weight loss to slow or stall at some point on GLP-1 treatment. Increasing activity, particularly strength work, can help with body composition even when the scales do not move much. Muscle is denser than fat, so you may lose inches without losing weight. Our guide to weight loss plateaus on GLP-1 medication explains what is normal and what to discuss with your prescriber.

Exercise for specific groups

Older adults

Muscle and bone loss with age make strength and balance work especially important for older people on GLP-1 treatment. The UK guidelines recommend balance and flexibility activities at least twice a week for older adults. Start gently and consider a supervised class. Our guide to GLP-1 medicines over 65 covers this.

People with joint pain or arthritis

Weight loss often reduces joint pain over time, but starting can be hard. Low-impact options, such as swimming, aqua aerobics, cycling and chair-based exercises, are kinder to joints. A physiotherapist can advise on suitable exercises. Many areas offer exercise referral schemes through GP practices.

People with heart or lung conditions

If you have heart disease, heart failure, angina, uncontrolled high blood pressure or significant lung disease, speak to your GP or specialist before starting a new programme. Cardiac rehabilitation and pulmonary rehabilitation services can offer supervised exercise.

People with a very high starting weight

Walking can be uncomfortable at first. Seated exercises, water-based activity and short, frequent bouts of movement are good starting points. Progress is progress, however small.

Staying motivated

• Set realistic, specific goals, such as walking for 15 minutes after lunch on five days this week, rather than vague ones.
• Track activity, not just weight. A step count, a log of sessions or noticing that stairs feel easier are all signs of progress.
• Find something you enjoy. You are more likely to keep going with activities you like.
• Exercise with others. Walking groups, parkrun (which welcomes walkers), classes and exercise referral schemes provide structure and company.
• Expect setbacks. Illness, side effects and busy weeks happen. Restart gently rather than giving up.

What support can you expect?

NHS weight management services and regulated online providers vary in the support they offer alongside medication. Some include access to physical activity advice, coaching or apps; others provide little beyond the prescription. If exercise support is important to you, ask about it before you start. Our guide to choosing an online pharmacy for weight loss and our provider comparison can help you compare services. For background on the medicines, start at our weight loss injections hub.

When to speak to a professional

Speak to your GP or prescriber before starting a new exercise programme if you:

• have heart disease, angina, heart failure, or have had a heart attack or stroke
• have uncontrolled high blood pressure
• have diabetes and take insulin or a sulphonylurea
• have significant joint, back or mobility problems
• have been very inactive for a long time and have other health conditions
• are pregnant or have recently given birth

Stop exercising and seek urgent help (call 999) if you experience:

• chest pain, pressure or tightness, especially if it spreads to your arm, jaw or back
• severe breathlessness that does not settle with rest
• fainting or collapse
• a sudden, severe headache, or weakness or numbness on one side of the body

Stop and contact your GP, prescriber or NHS 111 if you have:

• dizziness or light-headedness that keeps recurring
• symptoms of low blood sugar (shaking, sweating, confusion) if you have diabetes
• severe abdominal pain, with or without vomiting
• signs of dehydration, such as very dark urine, confusion or feeling faint

Decisions about your medication belong to your prescriber. This guide offers general information and is not a substitute for individual advice from a doctor, physiotherapist or qualified exercise professional.