At What Age Do You Start Losing Muscle?

Updated November 2, 2026 · By the DEXASCAN.COM Team

Key takeaways

• Muscle loss can start around age 30, at about 3–5% per decade, though it often isn't noticeable until around 60.
• A 47-year study of 427 Swedish adults found physical capacity started falling in the mid-30s and was 30–48% below peak by age 63.
• Men and women may lose muscle on different timelines, a 2026 Age and Ageing study suggests.
• Exercise can't stop the decline, but it slows it, and starting later in life still helps.
• DEXA, VO2 Max and RMR testing start at $89 on DEXASCAN.COM.

In October, ScienceDaily ran the headline "A 47-year study reveals the age when your body starts losing strength," and days later mindbodygreen covered new research on when women start losing muscle. The takeaway from both: this is a midlife conversation, not a retirement one. Here's what the research shows and how to find out where you stand.

At what age do you start losing muscle?

For most people, muscle loss begins quietly around age 30, and strength and fitness start to slide by the mid-30s.

According to womenshealth.gov, the body naturally loses about 3–5% of its muscle mass per decade starting around age 30, with changes tending to become more noticeable around age 60.

A rare long-term picture comes from the Swedish Physical Activity and Fitness study. Karolinska Institutet researchers followed 427 randomly selected men and women born in 1958 from age 16 to 63, publishing in the Journal of Cachexia, Sarcopenia and Muscle in 2025. They found:

• Aerobic fitness and muscular endurance generally peaked between ages 26 and 36, and explosive power peaked even earlier.
• Decline started around the mid-30s, modestly at first, then sped up.
• By age 63, average performance was about 30–48% below peak.

Keep in mind that the study measured physical performance, not muscle mass directly. Muscle also matters for calorie burn, which is why it comes up in the question of whether metabolism slows down with age.

Do men and women lose muscle differently?

They may. New research suggests men's losses speed up with age, while women's may show up earlier.

A 2026 paper in Age and Ageing looked at 895 adults in the Study of Muscle, Mobility and Ageing, using D3-creatine dilution, a method that estimates total skeletal muscle. In men, the estimated rate of loss rose from about 0.5% per year in younger adults to about 1.4% per year in the oldest group. In women, muscle mass was declining at about 0.6% per year in younger adulthood and then stayed relatively stable.

One caution: only 69 participants were under 70, so the findings for younger adults rest on a small group. As mindbodygreen reported, women's age-related differences in strength and fitness generally exceeded those in muscle mass, so muscle numbers alone may not tell the full story.

What is sarcopenia, and how do you know if you have it?

Sarcopenia is the gradual loss of muscle mass and strength that can occur with aging, especially in less active people. It may be a concern when that loss interferes with walking, standing up or carrying groceries.

The European EWGSOP2 criteria, summarized in a 2019 review in Polish Archives of Internal Medicine, use these cutoffs:

• Low grip strength: under 27 kg for men, under 16 kg for women
• Low muscle mass (limb muscle adjusted for height): under 7.0 kg/m² for men, under 5.5 kg/m² for women

On a DEXA report, the closest number is ALMI (appendicular lean mass index), the lean mass in your arms and legs divided by your height squared. Our ALMI explainer and visceral fat and ALMI guide cover how to read it. Only a clinician can diagnose sarcopenia.

How can you tell if you're losing muscle?

You usually can't tell from a bathroom scale, because your weight can stay the same while muscle drops and fat rises.

A DEXA scan (dual-energy X-ray absorptiometry) takes about 10 minutes on a padded table and shows:

• Body fat percentage, total and by region
• Lean muscle by region, including each arm and leg
• Visceral fat, the deep belly fat surrounding your organs
• Bone density

Because DEXA counts water and stored carbohydrate as lean tissue, one lower reading doesn't always mean lost muscle. Our guide to why a DEXA scan can show muscle loss explains what to check. The Big 3 testing page shows how DEXA pairs with VO2 max (the most oxygen your body can use during exercise) and RMR (the calories you burn at rest).

Can you rebuild muscle after 40, 50 or 60?

Research suggests yes. Training can't stop aging, but it can slow the decline and build strength.

• In the Swedish study, people who became active in adulthood improved physical capacity by about 5–10%. "It is never too late to start moving," lead author Maria Westerståhl said.
• A 2026 meta-analysis in European Review of Aging and Physical Activity pooled 25 randomized trials and 1,302 older adults with sarcopenia. Resistance training improved strength, walking ability and lean mass, though certainty was low to very low for function and performance.
• A small 2026 study in The American Journal of Medicine found 49 men aged 60 to 82 who began weekly resistance training improved upper and lower body strength over four years.

The CDC recommends at least 2 days of muscle-strengthening activity each week, working all major muscle groups. The meta-analysis authors suggested 2–3 sessions per week for older adults with sarcopenia. These tips for working out after 50 are a good start; pair training with enough protein to keep muscle.

What to do next

1. Lift at least twice a week, covering all major muscle groups.
2. Eat protein at each meal and talk with your provider before big changes.
3. Notice function, like how easily you climb stairs.
4. Get a baseline DEXA scan, then rescan every 8–12 weeks at the same location while you follow your plan.

If your waist is growing while your strength fades, read what sarcopenic obesity is and why the combination matters.

Frequently asked questions

How much muscle do you lose per decade?

According to womenshealth.gov, the body naturally loses about 3–5% of its muscle mass per decade, starting around age 30. Rates vary from person to person and with activity level.

What is a low ALMI on a DEXA scan?

Under the European EWGSOP2 sarcopenia criteria, low muscle mass is below 7.0 kg/m² for men and below 5.5 kg/m² for women. Strength is assessed too, so review your number with your healthcare provider.

Can you rebuild muscle after 50 or 60?

Research suggests you can. A 2026 meta-analysis of 25 randomized trials with 1,302 older adults with sarcopenia found resistance training improved strength and lean mass, though the evidence for some outcomes was low certainty.

How much does a DEXA scan cost?

Prices vary by location and provider. On DEXASCAN.COM, DEXA, VO2 Max and RMR testing start at $89, with prices shown upfront before you buy.

How often should I get a DEXA scan to track muscle?

Every 8 to 12 weeks is a practical interval while you follow a training or nutrition plan. Use the same location and keep conditions like hydration and timing consistent so your results are comparable.

Related reading

• How to Read Your DEXA Scan Report, Every Number Explained
• Want to Live Longer? Start by Tracking These Numbers
• How DEXA and VO₂ Max Work Together to Optimize Your Health

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Sources: ScienceDaily (Oct. 14, 2026); Karolinska Institutet (Dec. 2025); Hetherington-Rauth et al., Age and Ageing (2026); mindbodygreen (Oct. 2026); womenshealth.gov, "Sarcopenia"; Polish Archives of Internal Medicine (2019); European Review of Aging and Physical Activity (2026); CDC, Adult Activity: An Overview.

This article is for educational purposes and is not medical advice. Talk with your healthcare provider before starting or changing any medication, diet or exercise program.