Moving Less, Losing Strength: Women, Midlife and GLP-1s

The walk to work disappears when your job moves home. Groceries arrive at the door. A sore knee makes the elevator preferable to the stairs, and by the time the knee feels better, taking the elevator is automatic. You still think of yourself as a reasonably active person. But compared with five years ago, you spend much more of the day sitting.

You might notice it first when you travel. The suitcase you used to put in the overhead bin now needs someone else’s help. At home, you’ve stopped carrying both grocery bags upstairs at once. Each adjustment is small enough to dismiss, especially when work and family leave you tired anyway.

For women in their late thirties and forties, weight often gets far more attention than strength. That becomes a problem when the scale is the only measure of success on a weight-loss medication. Eating less may be getting easier while the activities you used to manage are getting harder.

How doing less becomes normal

Deconditioning is the loss of physical capacity that follows reduced activity. Once the stairs feel harder, you’re less inclined to take them. The occasional weekend workout can obscure how little movement remains during the rest of the week.

There is a name for the energy spent on movement outside deliberate exercise: non-exercise activity thermogenesis, or NEAT. Walking between appointments counts. So does being on your feet doing housework. A commute that once included twenty minutes of walking each way can account for a substantial change in your routine when it disappears, even if your gym attendance stays the same. [1]

Reduced use also changes how muscle responds to food. In an experiment involving ten adults with an average age of 72, cutting daily steps to roughly 1,400 for two weeks reduced leg lean mass. Their muscle-building response to feeding weakened too, a change known as anabolic resistance. The experiment involved a sharp reduction in activity in older people, but it helps explain the biological connection between using muscle and maintaining it. [2]

You may also hear the word sarcopenia. That is a clinical diagnosis involving low muscle strength and reduced muscle quantity or quality, assessed through measurements rather than appearance. Feeling out of shape is a reason to look at what has changed, not a diagnosis in itself. [3]

What changes around menopause

In the Study of Women’s Health Across the Nation, researchers followed body composition in 1,246 women, whose average age at the start of the analysis was 47. Around the menopause transition, they observed faster fat gain and a decline in lean mass. Weight gain did not accelerate in the same way because the changes in fat and lean tissue partly offset each other. [4]

Your weight can therefore conceal a change in body composition. That matters if you’ve been judging your health mainly by whether your clothes fit or whether you’ve gained a few pounds. The menopause transition adds a biological reason to pay attention to muscle alongside the changes in activity that may already have happened.

For a woman approaching menopause, a conversation about weight should include what she can comfortably do. Has she stopped attending a class because she can’t keep up? Is she avoiding a walk she used to enjoy? Those changes can get lost in an appointment focused on the number on the scale.

When weight loss includes lean tissue

Semaglutide and tirzepatide can produce substantial weight loss. Some of that loss is lean tissue, which includes skeletal muscle but also water and other non-fat tissues. A scan showing a kilogram less lean mass does not mean a kilogram of muscle has disappeared. Nor does it tell you how much strength someone has lost. [5,6]

In the manufacturer-sponsored SURMOUNT-1 trial, 160 participants had body-composition scans at the beginning and end of treatment; 73% were women. Over 72 weeks, about three-quarters of the weight lost with tirzepatide was fat and one-quarter was lean mass, on average. The placebo group lost much less weight but had a similar split between fat and lean tissue. [5]

A 2026 review found no consistent deterioration in strength or physical function across the studies it examined, while identifying longer-term muscle outcomes as an area needing more research. Measuring someone’s ability to move and lift gives information that a lean-mass estimate alone cannot provide. [6]

Meanwhile, daily habits can change quickly after starting treatment. Breakfast becomes optional because you aren’t hungry. Lunch is smaller, and nausea makes dinner unappealing. If you were already doing little strength training, reduced food intake adds to the concern. The 2025 joint advisory from four medical societies identifies both factors, along with the extent and speed of weight loss, as reasons to monitor muscle health. [7]

For side effects and what to discuss before starting treatment, see our guide to GLP-1 medications and family care.

Protein needs a place in the day

“Eat more protein” is frustrating advice when half a meal leaves you full. Start by logging a few typical days in a food-tracking app. Check the portions and entries so you have a reasonable estimate of what you’re eating. You may find that breakfast and lunch contribute very little, leaving dinner to supply most of the day’s protein. A dietitian can help if making changes proves difficult or you have dietary needs that require individual advice. [7]

Choose foods you can comfortably eat in those smaller meals. Yogurt at breakfast or beans added to lunch may fit more easily than trying to finish a large serving at dinner. A protein-containing meal replacement is another option when ordinary meals are difficult. Your protein target should account for your health and body size. [8]

Protein alone is unlikely to preserve muscle adequately without resistance exercise. The joint advisory explicitly pairs the two. [7]

If you regularly cannot finish enough food, tell the prescriber, especially if the problem began after a dose increase. Persistent nausea or fullness may call for changes to the treatment plan. Expert recommendations include managing these symptoms and adjusting dose progression to the individual. [9]

Start with two strength sessions

Canadian movement guidelines recommend strengthening the major muscle groups at least twice a week for adults aged 18–64, alongside aerobic activity and less prolonged sitting. [10] Put two sessions in the calendar and decide where they will happen. A class near work may be easier to attend than a gym that requires another trip across the city.

You can also train at home with resistance bands or weights. Begin at a level you can manage, then increase the challenge as you get stronger. If an old injury makes you unsure where to start, a physiotherapist or qualified exercise professional can help adapt the exercises. GLP-1 supportive-care recommendations call for a program that changes with your capacity. [9]

Between sessions, look at where walking used to fit into your day. If working from home removed the commute, a walk before you open the laptop can restore some of that time on your feet. Our article on walking and diabetes prevention covers the evidence for activity built into daily routines.

What to check at the next appointment

A follow-up should get specific about a change in strength. If you’ve started using your arms to push yourself out of a chair, say so. Your doctor can assess whether pain is limiting the movement and, when appropriate, time five chair rises without arm support or measure grip strength with a handheld device. Repeating the same assessment later helps track the change. [3]

Bring the food log if you’ve kept one. Describe what happened after your last dose increase, including whether you stopped exercising because you felt unwell. These details help the prescriber decide whether to address food intake or medication tolerance, and whether the weakness needs a separate assessment. [9]

Persistent weakness also needs attention if you aren’t taking a weight-loss medication. Be clear about when it started and whether it is getting worse. “I used to carry the groceries upstairs in one trip; now I need help” tells the doctor more than “I think I’m getting older.”

Before you leave, agree on what to follow up. If getting back to your exercise class is the goal, the next appointment should include whether you’ve managed to return and what is still making it difficult.

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References

1. Levine JA. Non-exercise activity thermogenesis (NEAT). Best Practice & Research Clinical Endocrinology & Metabolism, 2002;16(4):679–702. DOI: 10.1053/beem.2002.0227.

2. Breen L, et al. Two weeks of reduced activity decreases leg lean mass and induces “anabolic resistance” of myofibrillar protein synthesis in healthy elderly. Journal of Clinical Endocrinology & Metabolism, 2013;98(6):2604–2612. DOI: 10.1210/jc.2013-1502.

3. Cruz-Jentoft AJ, et al. Sarcopenia: revised European consensus on definition and diagnosis. Age and Ageing, 2019;48(1):16–31. DOI: 10.1093/ageing/afy169.

4. Greendale GA, et al. Changes in body composition and weight during the menopause transition. JCI Insight, 2019;4(5):e124865. DOI: 10.1172/jci.insight.124865.

5. 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;27(5):2720–2729. DOI: 10.1111/dom.16275.

6. De Girolamo G, et al. Muscle health in the modern era of incretin-based therapies. European Journal of Clinical Investigation, 2026;56(1):e70155. DOI: 10.1111/eci.70155.

7. Mozaffarian D, et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and the Obesity Society. American Journal of Lifestyle Medicine, 2025. DOI: 10.1177/15598276251344827.

8. American Association of Clinical Endocrinology. Nutritional considerations for patients on obesity medications. Clinical educational resource. Accessed September 2026.

9. Sievenpiper JL, et al. Nutritional and lifestyle supportive care recommendations for management of obesity with GLP-1-based therapies: an expert consensus statement using a modified Delphi approach. Obesity Pillars, 2026;17:100228. Published online November 2025. DOI: 10.1016/j.obpill.2025.100228.

10. Canadian Society for Exercise Physiology. Canadian 24-hour movement guidelines for adults aged 18–64 years: an integration of physical activity, sedentary behaviour, and sleep. 2020.