Why your muscles start shrinking in midlife and how to stop it
Published on 30 October 2025
Muscle loss can begin in your forties, quietly eroding strength, balance and metabolism. Here’s how to keep them strong for life.
At a glance
- Muscle loss can begin in your forties
- Affects one in three older adults in Singapore
- Strength training and smart protein choices help slow it down
The midlife muscle wake-up call
You might notice it when the stairs feel steeper, the grocery bags heavier or jars harder to open. What’s quietly slipping away is muscle — and it can start in your forties.
Doctors warn that this “midlife muscle loss,” known medically as sarcopenia, is setting in decades before retirement. It weakens strength, slows metabolism and raises the risk of frailty, falls and slower recovery from illness later in life.
The good news: muscle loss is not inevitable.
A mix of regular strength training and smart protein choices can preserve strength, metabolism and independence well into older age.
Why it matters
Nearly one in three older Singaporeans has significant muscle loss. But among adults under 60 with chronic conditions, one in 14 already show early decline.
Muscles do far more than move us. They stabilise balance, regulate metabolism and help the immune system fight infection. As we age, the body becomes less efficient at building and repairing muscle proteins — a process called anabolic resistance.
In men, sarcopenia tends to begin in the mid-forties and fifties. In women, it often accelerates during perimenopause as oestrogen levels fall, making it harder for the body to maintain and rebuild muscle.
“As we age, our muscles become less efficient at repairing and building new proteins, making it harder to maintain strength and muscle mass,” said Assoc Prof Reshma Merchant, Head and Senior Consultant, Division of Geriatric Medicine, Department of Medicine, National University Hospital (NUH).
Eat for strength, not just energy
Forget low-carb diets. The real midlife secret is protein and how you use it.
“Research over the past decade has shown that adequate protein is essential for muscle repair, growth and preservation,” said Assoc Prof Reshma. “It’s critical for healthy ageing and metabolic balance.”
A balanced midlife diet should pair high-quality protein with complex carbohydrates such as whole grains, legumes, fruit and vegetables. Protein preserves lean muscle, while complex carbohydrates provide fibre and energy.
“Without enough carbohydrates, the body may start breaking down muscle protein for energy, accelerating muscle loss,” she added.
Avoid refined carbohydrates, sugars and ultra-processed foods. Try practical pairings like eggs on wholegrain toast or Greek yoghurt with fruit.
Smart protein choices
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After exercise
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How much protein do you need?
As we get older, our bodies become less efficient at using protein to rebuild and maintain muscle. That means we need a little more to get the same benefit as before.
| Guideline | Details | Example |
| Basic requirement | 0.8 g of protein per kg of body weight daily – enough to prevent deficiency but not to guard against age-related muscle loss. | A 70 kg adult needs about 56 g of protein — the minimum needed to prevent deficiency. |
| Optimal for midlife and older adults | 1 to 1.2 g of protein per kg daily helps maintain and rebuild muscle. | For a 70 kg adult, that’s about 70 to 100 g of protein — roughly the amount in two chicken breasts and a serving of lentils. |
| Best timing | Spread protein evenly across meals, about 25–30 g per meal, and pair with resistance training. | Try eggs on wholegrain toast for breakfast, tofu stir-fry for lunch, and fish with vegetables for dinner. |
Note: People with chronic kidney disease (CKD) or gout may need to moderate their protein intake. Before making significant dietary changes, consult your doctor or dietitian to tailor your protein goals to your health and kidney function.
After a workout, have a protein-rich snack within an hour to help the body rebuild muscle. Pair it with some carbohydrate, for example a fruit and whey smoothie, to further boost recovery.
Why protein and exercise work better together
Food and movement go hand in hand. Strength training creates tiny tears in muscle fibres, and protein provides the building blocks to repair them, making muscles stronger and more resilient.
Start small: two or three resistance sessions a week using your own body weight, resistance bands or light weights. Gradually increase resistance or repetitions as your strength improves.
If you eat protein but rarely move, your body will use those amino acids for energy or store them as fat. If you exercise but eat too little protein, your muscles cannot rebuild efficiently.
The message is simple: it’s never too late to start.
“Regular strength training plus enough high-quality protein can slow or even reverse muscle loss,” said Assoc Prof Reshma. “It helps maintain strength, mobility and independence as we age.”
In consultation with Assoc Prof Reshma Merchant, Head and Senior Consultant, Division of Geriatric Medicine, Department of Medicine, NUH.
