Muscle loss is often associated with old age, but experts warn that a condition known as sarcopenia can begin much earlier, potentially affecting people in their 20s and gradually weakening their ability to carry out everyday activities.
Sarcopenia refers to the age-related loss of muscle mass and strength. Although it may not be immediately noticeable, the condition can eventually make simple tasks such as getting out of a chair, climbing stairs and carrying groceries increasingly difficult.
Clinical Associate Professor Frederick Koh, Deputy Research Director at Sengkang General Hospital, explained that the body’s ability to build and repair muscles becomes less efficient as people age. This is linked to changes in muscle protein synthesis, declining levels of hormones that support muscle growth and reduced physical activity.
Consequently, skeletal muscles gradually lose size and mass as their fibres shrink or disappear. Fat may also accumulate within and around the muscles, reducing their quality.
One challenge is that sarcopenia may not change a person’s physical appearance or body measurements, meaning the condition can go unnoticed until it reaches a more advanced stage.
Although it is commonly regarded as an older person’s problem, Dr Koh said muscle loss begins much earlier. Adults aged 60 and above are estimated to have a one-in-three chance of developing sarcopenia.
People begin losing up to 8% of their muscle mass every decade from the age of 40, while muscle loss of around 3% to 5% per decade can start after 30.
Research findings from Singapore’s PRECISE-SG100K cohort also suggest that approximately 25% of adults below 39 already had sarcopenia. The large-scale Asian population study contains data from around 100,000 residents aged between 21 and 84.
Dr Agnes Siew Ling Tey, a Volwiler associate research fellow in Clinical Science and Nutrition at Abbott Nutrition Research and Development, said some individuals could develop the condition in their 20s.
She explained that younger adults may already have lower-than-optimal muscle levels due to physical inactivity, inadequate nutrition or underlying health conditions.
DIABETES, MENOPAUSE AND JOINT PAIN
Preliminary findings from Project MAGNET, an initiative by Duke-NUS Medical School and SingHealth investigating age-related muscle loss, suggest that men may have higher rates of sarcopenia than women in Singapore.
Dr Koh, who is the project’s clinical lead and principal investigator, said this differs from findings commonly reported internationally, where sarcopenia is generally considered more prevalent among women.
Further research is needed to understand the findings, while the project uses Asia’s largest sarcopenia biobank to investigate ways of improving diagnosis and treatment.
Dr Koh also stressed the importance of developing Asian-specific reference values and diagnostic criteria because Asians generally have different body composition profiles compared with Western populations.
Researchers are also examining the relationship between sarcopenia and Type 2 diabetes, as Asians are more prone to developing the condition than Caucasians.
Insulin normally helps muscles absorb glucose while supporting their growth and repair. However, insulin resistance makes it harder for muscles to use glucose effectively and maintain themselves.
Type 2 diabetes is also associated with chronic inflammation, which can interfere with muscle regeneration and contribute to muscle loss over time. People with the condition therefore face a higher risk of developing sarcopenia.
Menopause may also increase the risk, as declining oestrogen levels have been associated with greater abdominal fat, reduced bone density and losses in muscle mass and strength.
However, Dr Koh said the exact role of oestrogen in the development and progression of sarcopenia remains under investigation. Ageing, physical activity, nutrition and chronic illnesses are also important contributing factors.
Joint problems can further complicate the condition. Although joint degeneration and sarcopenia are different, weaker muscles provide less support and shock absorption around joints, potentially increasing stress and worsening symptoms.
At the same time, joint pain may cause people to reduce their exercise intensity, potentially accelerating further muscle loss.
HOW CAN SARCOPENIA BE DETECTED?
Hospitals and clinics in Singapore use several assessments to identify people who may have sarcopenia.
One commonly used method is the Short Physical Performance Battery (SPPB), which evaluates a person’s ability to maintain balance in different positions, walking speed and ability to repeatedly stand up from a chair.
Tan Tock Seng Hospital also offers body composition assessments, including Dual-energy X-ray Absorptiometry (DEXA) and Bioelectrical Impedance Analysis (BIA), alongside blood tests and handgrip strength assessments.
Dr Daphne Yang, a consultant in Geriatric Medicine at the hospital, said doctors may also examine tongue pressure in patients with oral frailty or swallowing difficulties, as sarcopenia can affect the muscles responsible for chewing and swallowing.
At Alexandra Hospital, the SARC-F questionnaire is used alongside the SPPB to identify people who may be at risk.
Dr Jeremy Teng, an associate consultant with the hospital’s Healthy Ageing Programme, said the five-question screening tool is scored from zero to 10. A score of four or higher indicates a high risk of sarcopenia and the need for further assessment.
WHEN SHOULD YOU GET CHECKED?
Dr Tay Yu Ling, a consultant with Singapore General Hospital’s Department of Geriatric Medicine, said muscle loss accelerates after 60.
Adults aged 65 and above, particularly those with chronic illnesses, repeated falls, malnutrition or declining physical abilities, should be assessed.
Warning signs include weakness and difficulty carrying a load weighing 4.5kg, walking, getting up from a chair or climbing stairs, as well as experiencing falls.
However, Dr Teng said people should consider screening earlier, as skeletal muscle mass declines more rapidly after 50.
Asian sarcopenia guidelines have recommended a case-finding approach to detect the condition from the age of 50 onwards.
Dr Siew said muscle health should be monitored alongside other important health indicators, much like blood pressure is checked before hypertension develops and bone health is assessed before fractures occur.
UNDERSTANDING THE DIFFERENT TESTS
DEXA scans can assess bone density and body composition using the same machine, although different scanning modes are required. Dr Yang cautioned that images taken for bone density cannot be used to interpret body composition, and vice versa.
The Asian Working Group for Sarcopenia (AWGS) updated its diagnostic criteria in 2025 to account for height and body mass index (BMI). This is because taller people and those with larger body frames naturally have more absolute muscle mass than shorter or smaller individuals.
According to Dr Teng, DEXA uses a small amount of ionising radiation to produce images of the inside of the body.
The following measurements indicate a higher risk of sarcopenia under the updated criteria:
| DEXA measurement | Age 50–64 | Age 65 and above |
|---|---|---|
| Height-adjusted muscle mass – men | Below 7.2 kg/m² | Below 7.0 kg/m² |
| Height-adjusted muscle mass – women | Below 5.5 kg/m² | Below 5.4 kg/m² |
| BMI-adjusted muscle mass – men | Below 0.80 | Below 0.73 |
| BMI-adjusted muscle mass – women | Below 0.55 | Below 0.52 |
Another option is BIA, which uses a low-intensity alternating electrical current to estimate muscle mass.
Dr Teng cautioned that people with pacemakers or other cardiac devices should avoid using BIA because it involves an electrical current.
BIA machines are available in hospitals, gyms and for home use, but their accuracy varies depending on the equipment. Dr Yang said DEXA provides more accurate muscle mass measurements.
For those using BIA, she recommended choosing a machine with a strong correlation to DEXA measurements and consistently using the same device, as different machines may have different cut-off values.
The AWGS measurements indicating a higher risk of sarcopenia through BIA are:
| BIA measurement | Age 50–64 | Age 65 and above |
|---|---|---|
| Height-adjusted muscle mass – men | Below 7.6 kg/m² | Below 7.0 kg/m² |
| Height-adjusted muscle mass – women | Below 5.7 kg/m² | Below 5.7 kg/m² |
| BMI-adjusted muscle mass – men | Below 0.90 | Below 0.83 |
| BMI-adjusted muscle mass – women | Below 0.63 | Below 0.57 |
Handgrip strength is another important assessment because sarcopenia affects not only muscle mass but also physical strength, potentially leading to fatigue.
Dr Yang said muscle strength has been shown to provide a more consistent indication of poor health outcomes than muscle mass alone.
The test is commonly performed using Jamar or Smedley dynamometers. However, the two devices produce different measurements and should not be compared directly, as Smedley devices consistently record lower readings.
For more reliable predictive results, Dr Yang recommended recording the highest measurement from at least two readings on each hand rather than calculating the average.
The AWGS thresholds indicating a higher risk are:
| Handgrip strength | Age 50–64 | Age 65 and above |
|---|---|---|
| Men | Below 34kg | Below 28kg |
| Women | Below 20kg | Below 18kg |
Gait speed, which measures a person’s usual walking pace, is also used to assess mobility, lower-limb function and overall physical reserves.
A walking speed below 1.2 metres per second indicates a higher risk for both men and women aged 50 to 64. For those aged 65 and above, the threshold is below one metre per second.
Doctors may also measure calf circumference as an initial screening method because it can provide an indication of muscle mass.
Dr Teng said calf measurements are particularly relevant because a person can have obesity and sarcopenia at the same time, making thigh measurements potentially less reliable.
However, she stressed that calf circumference is only a rough screening measure and is less accurate than BIA or DEXA. It cannot be used to diagnose sarcopenia.
A calf circumference below 34cm for men and 33cm for women may indicate a higher risk.
Blood tests can also help identify medical conditions associated with sarcopenia, including diabetes, chronic heart, lung, liver and kidney diseases, osteoporosis and malnutrition.
Dr Yang added that adequate Vitamin D is important for both muscle and bone health. A blood level of 25-hydroxyvitamin D should be at least 30ug/L.
CAN EXERCISE AND NUTRITION REVERSE MUSCLE LOSS?
Strength training can help improve sarcopenia, although the process of building muscle is generally less efficient in people who already have the condition, Dr Koh said.
During the early stages, the body can still activate compensatory mechanisms to preserve muscle health. However, as sarcopenia progresses, its ability to repair and regenerate muscle becomes increasingly impaired due to a decline in the number and function of muscle stem cells.
Fat and scar tissue may also build up within muscles, while muscle fibres that lose their nerve supply can eventually disappear. As a result, people with sarcopenia may experience slower or smaller improvements in muscle mass and strength compared with those without the condition.
Nevertheless, muscle tissue remains responsive to intervention, even after sarcopenia develops.
Dr Koh said resistance exercise and adequate nutrition, particularly sufficient protein intake, can improve muscle strength, physical function and mobility.
Although short-term interventions may not completely restore lost muscle mass, they can help the body use its remaining muscles more effectively and improve resilience during stressful periods, including surgery and illness.
