Sarcopenia: the silent muscle loss that begins long before retirement
Most people are familiar with osteoporosis. Far fewer are familiar with sarcopenia – even though it affects more people, starts earlier and impacts everyday life more directly. Here's what it's all about, why it occurs and what the research actually says about reversing the trend.
What is sarcopenia?
Sarcopenia is the age-related loss of muscle mass, muscle strength, and muscle function. The word comes from the Greek sarx (flesh) and penia (lack) and was coined in the 1980s. Since 2016, it has been classified as a separate diagnosis in the international diagnostic register ICD-10 – that is, a medical condition, not an inevitable part of getting older.
For a long time, sarcopenia was defined solely based on how much muscle mass a person had. The European expert group EWGSOP changed this in 2018. In today's definition, low muscle strength is the decisive criterion, while low muscle mass confirms the diagnosis and impaired physical function shows how severe it is.
The shift is not academic hair-splitting. Strength declines about three times faster than mass as we age. So you can have seemingly normal muscle volume and yet have lost a significant portion of your ability to use it. It is also strength—not mass—that best predicts falls, hospitalizations, and premature death.
How fast does it go?
Muscle mass peaks somewhere between the ages of 25 and 35. After that, a slow decline begins that accelerates over time. Without exercise, we're talking about three to eight percent per decade from the age of 40, and after 70, the rate increases even further.
Over three decades, that means a significant portion of your muscle mass could be gone before you turn 70 – without you ever noticing a clear threshold moment. That’s why sarcopenia is often called silent. Nothing hurts. You just notice one day that that suitcase has gotten heavier.
The process is also not linear. Two weeks in bed after surgery, the flu, or a foot in a cast can cost more muscle than years of normal aging – and they won't come back on their own when you're back up.
Why do we lose muscle?
Several processes work simultaneously, and they reinforce each other:
The nervous system disconnects. The number of motor neurons that control muscles decreases with age, especially those that control the fast fibers – the ones we use to catch ourselves when we stumble.
The body responds less well to protein. The phenomenon is called anabolic resistance: an older body needs more protein per meal than a younger one to kick-start muscle building.
We move less. Retirement, sore knees and a more comfortable everyday life reduce the load, and muscles that are not used are broken down.
Hormone levels drop and low-grade inflammation increases over the years, both of which are detrimental to muscle building.
Note that only two of these four are outside of your control. Load and protein intake are things you decide on yourself – and they affect the other factors in turn.
Warning signs in everyday life
Sarcopenia rarely announces itself as a health problem. It manifests itself as practical annoyances: that you use your hands to support yourself when getting up from the couch, that you start holding onto the handrail on the stairs, that the screw cap on the jar suddenly requires help, that you walk slower than the group, or that you no longer have the strength to carry both grocery bags home in one go.
Each of these is easily explained away by age. Together, they form a pattern worth taking seriously.
How the diagnosis is made
In healthcare, the assessment often begins with a simple questionnaire, SARC-F, which asks five questions about strength, walking ability, getting up from a chair, climbing stairs, and whether you have fallen in the past year. Strength and function are then measured against fixed thresholds.
European limit values (EWGSOP2)
Test | Limit value men | Limit value women |
Grip strength | under 27 kg | under 16 kg |
Get up from a chair, 5 times | over 15 seconds | over 15 seconds |
Walking speed | 0.8 m/s or lower | 0.8 m/s or lower |
Muscle mass (DEXA) | below 7.0 kg/m² | below 6.0 kg/m² |
The thresholds are set to catch those who already have a problem. So being just above them is not a concession – it is a signal that it is time to act.
You can do two of the tests at home today. Time how long it takes you to get up from a chair five times without using your arms, and measure how long it takes you to walk four meters at your usual pace. Write down the numbers. They are your starting point.
What is at stake?
Sarcopenia is strongly linked to falls and fractures, loss of independence in everyday life, and poorer recovery from surgery and illness. The condition also co-varies with type 2 diabetes, cardiovascular disease, osteoporosis, and an increased risk of premature death.
Muscles are also the body's largest store of blood sugar. Less muscle mass means fewer places to dispose of the sugar – which is part of the explanation for the link to diabetes.
There is also research that suggests a link between preserved strength and better cognitive function and mental well-being. The evidence is thinner there, so consider it a likely bonus rather than a promise.
How to turn the tide
There is currently no approved drug for sarcopenia. The treatment is strength training and sufficient protein – and it works even in people well over 80.
Strength training is the single most important measure.
Expert recommendations are at least two sessions per week that cover the body's major muscle groups, with 1–4 sets of 8–15 repetitions per exercise. Start with a load that you can handle with good technique and increase gradually. Body weight, rubber bands, machines or dumbbells play less of a role – the key is that the resistance increases over time.
Feel free to add speed.
Getting up from a chair or pushing your body up with the intention of doing it quickly trains the explosive fibers, which are the ones you lose first and which determine whether you have time to catch yourself when you stumble. Supplement with balance training a few times a week and cardio training for about half an hour most days.
Protein is the other half.
The recommendation for healthy older adults is around 1.0–1.2 grams per kilogram of body weight per day, or 75–90 grams for a 75-kilogram person – clearly more than the official minimum value for younger adults. In cases of illness or rehabilitation, the need is higher.
The distribution also matters. Many of us eat a low-protein breakfast, a mediocre lunch, and then everything at dinner. Since an older body needs a certain amount of protein at each meal to kick-start muscle building, the first two opportunities are wasted. Aim for a decent source of protein at each meal – eggs, dairy, fish, meat, beans, or lentils.
Finally, make sure you get enough sleep and overall energy intake.
Training hard while eating too little is an effective way to lose muscle instead of building it.
This also applies to you who are 45.
Sarcopenia is often described as a problem for the very oldest. But the process starts in middle age, and that's when the effort pays off the most. The more muscle mass and strength you carry with you into your 70s, the more margin you have when illness, surgery, or a period of inactivity inevitably comes.
There is no age at which the body stops responding to stress.
Studies on people well over 80 show clear improvements in both strength and muscle mass after a few months of training. So it's never too late – but every year you wait is a year of margin you give away.
In conclusion
Sarcopenia is a diagnosis, not a fate. It develops silently over decades, is measured primarily as lost strength rather than lost volume, and the only treatment that works is the one you do yourself: resistance training twice a week and enough protein, spread out throughout the day.
Start by timing five times you stand up from a chair. Write down the number. Retake the test in three months. That's all the evaluation you need to know if you're on the right track.
Want to get started?
In the Bodyweight Diet app, you train with your own body weight – at home, without equipment and at a pace that is adapted to a body over 50. Download the app and try our free 7-day program, and you will get strength training, a diet plan and a plan to follow from day one.
All the best, Kennet Båth
The content is general information and does not replace individual medical advice. Contact your healthcare provider if you suspect that your strength or walking ability has significantly deteriorated.
