Why Muscle Matters During Weight Loss for Women

Category: Women's Health

When you're working on your weight, it's easy for the number on the scales to become the main event. But there's a quieter, equally important question running alongside it: what's happening to your strength?

This is particularly relevant for women — especially those navigating perimenopause and beyond — where muscle mass naturally declines with age, a process called sarcopenia. Understanding why muscle deserves attention during weight loss isn't about adding pressure to an already full plate. It's about making sure the effort you're putting in works harder for you.

What the Evidence Actually Shows

Weight loss doesn't happen in a vacuum. When the body sheds kilograms, it loses a combination of fat tissue and lean tissue — and lean tissue includes muscle. This matters more than many people realise.

A 2025 systematic review published in BMJ Open Sport and Exercise Medicine examined 25 randomised controlled trials involving adults aged 18 to 65 with overweight or obesity. The researchers found that adding resistance exercise to dietary weight loss helped preserve fat-free mass and increased fat loss compared with dietary changes alone. Strength also improved, though the certainty of that evidence was rated as lower. Notably, total weight lost was not significantly different between groups.

That last point is worth sitting with. The scales may tell a similar story whether or not you include strength work — but what's happening inside your body can be quite different.

One important clarification: "fat-free mass" is not the same as muscle mass. It includes bone, water, connective tissue, and organs. So while the findings are encouraging, they shouldn't be read as a precise muscle-preservation guarantee. What they do suggest is that resistance exercise offers meaningful benefits that a weight reading alone won't capture.

Source: Binmahfoz et al., BMJ Open Sport and Exercise Medicine, 2025.

Why Strength Matters Beyond the Gym

Think about the physical tasks that make up a normal day:

Carrying groceries from the car
Getting up from the floor after playing with a child or grandchild
Taking the stairs without thinking twice
Lifting a suitcase into the overhead locker

These are functional strength tasks — and they're a useful lens for setting goals. Rather than framing exercise purely around weight loss, consider what you want your body to keep doing with ease and confidence. Functional capacity and independence are legitimate health goals in their own right, supported by strong evidence across the lifespan.

For women in midlife particularly, maintaining muscle mass is associated with:

Better metabolic health and improved insulin sensitivity
Reduced risk of falls and fractures
Better long-term weight maintenance

The Australian Institute of Health and Welfare recognises musculoskeletal health as a national health priority area, and the evidence base for resistance training in women's health continues to grow.

What Counts as Resistance Exercise?

Resistance exercise simply means asking your muscles to work against a load. That load doesn't have to come from a gym. It can be your own body weight, a resistance band, a set of dumbbells, or gym-based equipment — whatever suits your current ability, access, and confidence.

Practical starting points include:

Chair stands (sitting to standing without using your hands)
Wall push-ups
Resistance band rows or bicep curls
Step-ups onto a low step
Glute bridges on the floor

The guiding principle is progressive overload — gradually increasing the challenge as movements become easier, whether that means more repetitions, more resistance, or a more complex variation.

Current physical activity guidelines from the World Health Organization and Australia's national guidelines recommend that adults engage in muscle-strengthening activities targeting all major muscle groups on at least two days per week, in addition to regular aerobic activity such as brisk walking. Even a short session is a valid starting point.

Sources: WHO Global Guidelines on Physical Activity and Sedentary Behaviour, 2020; Australian Government Department of Health Physical Activity Guidelines.

Making It Realistic When Life Is Already Full

Adding a structured exercise programme to a busy life can feel like one more commitment to fall behind on. That pressure isn't helpful — and it isn't necessary.

A more sustainable approach is to identify two short windows in your week where strength work is genuinely possible. Decide in advance on the time, the place, and two or three movements you'll do. Ten minutes is enough to begin building a habit. At this stage, the goal is consistency, not intensity.

If you're dealing with pain, a previous injury, pelvic floor symptoms, or simply don't know where to start, an accredited exercise physiologist or physiotherapist can design a programme appropriate to your specific circumstances. These professionals are trained to work with people at all fitness levels, including those managing chronic health conditions.

You can also raise this directly at your next Downscale Health appointment. A useful question to bring is:

"How can we support my muscle health while I'm working on my weight?"

Your care team can help integrate strength goals into your overall plan, taking your health history and current medications into account.

Putting It Together This Week

If you've been working on your protein intake, keep that habit in place. Adequate protein — the RACGP and international obesity guidelines generally support a target of around 1.2 to 1.6 grams per kilogram of body weight for adults in active weight management — works alongside resistance exercise to support muscle tissue during a calorie deficit.

This week, the focus is simple: identify two realistic opportunities to do some form of strength work. Start where you are. Build from there.

The scales are one data point. Your strength, your energy, and what your body can do are others — and they deserve a place in the conversation.

This content is for general education only. Nutrition and exercise recommendations should always be tailored to your individual health, medical history, and circumstances. Speak with your GP or treating clinician before beginning a new exercise programme.