Sarcopenia is the muscle you've been losing since 30

Sarcopenia means losing muscle and the strength that goes with it

Two expert groups set the definitions most doctors and researchers use today. The European Working Group on Sarcopenia in Older People met in 2018 and published its update, known as EWGSOP2, in 2019. It puts strength first. Low strength makes sarcopenia probable, low muscle quantity or quality confirms it, and if physical performance is low as well, which means things like how fast you walk, it counts as severe. The group describes it as a kind of muscle failure rooted in changes that build up across a lifetime, and notes it can occur earlier in life too.¹

The Asian Working Group for Sarcopenia updated its own version in 2019, with its own cut-offs for Asia. It uses the same building blocks of muscle mass, strength and physical performance, and adds a category called possible sarcopenia, where only strength or performance is low, so people can start making changes earlier.²

How common it is depends on which definition you use. A 2022 analysis pooled 151 studies covering 692,056 people with an average age of 68.5. Among those aged 60 and over, between 10% and 27% had sarcopenia, so up to about one in four, and 2% to 9% had the severe form.³ The spread is wide because the studies used different definitions and cut-offs, and a prevalence figure only counts people who have crossed a line. It says nothing about the slow loss that happens before anyone gets there.

The loss starts quietly from about 30

A 2004 review in Current Opinion in Clinical Nutrition and Metabolic Care put the loss at roughly 3 to 8% of muscle mass per decade after 30, and faster after 60.⁴ That figure comes from earlier population studies the review draws on, so treat it as a range rather than a measurement of any one person.

A 2012 review pulled together the studies that had measured muscle size and strength across adult life. Where studies compared young adults with people over 65, the typical loss worked out at about 0.47% of muscle a year for men and 0.37% for women. Studies that followed the same people over time found that at around 75, men lost 0.80% to 0.98% a year and women 0.64% to 0.70%.⁵ Half a percent a year does not sound like much. Over two or three decades it adds up.

You feel the strength go before you see the muscle go

The same 2012 review found that strength drops much faster than size. Around 75, men in the long-running studies lost 3% to 4% of their strength a year and women 2.5% to 3%. In studies that measured both in the same people, strength fell two to five times faster than muscle mass.⁵ Part of the reason is muscle quality, which is how much force each bit of muscle can produce. So strength can slip faster than size does.

The review also found that losing strength was more consistently linked to trouble with everyday activities than losing muscle mass.⁵ That is why the European group now leads with strength.¹

In daily life it shows up as the suitcase that feels heavier, the stairs that feel longer and the jar that will not open. In a clinic it shows up in two simple tests. One is grip strength, measured by squeezing a hand-held gauge. The European cut-offs are below 27 kg for men and 16 kg for women, and the Asian ones below 28 kg and 18 kg. The other is the chair stand, standing up from a chair five times. More than 15 seconds is the European flag, and 12 seconds or more is the Asian one.^1,2

Strength training gives your muscle a reason to stay

Strength training, also called resistance exercise, means working your muscles against a load, whether that is weights, bands or your own body. A 2011 analysis pooled 49 studies with 1,328 adults aged 50 and over who took up resistance exercise. On average they gained about 1.1 kg of lean body mass, which is everything in the body that is not fat, mostly muscle but also water and organs.⁶

Programmes with more total work gave bigger gains. The oldest participants gained less than the younger ones, though they still gained. The studies differed a lot in how they were run, and lean mass is not quite the same thing as muscle, so the 1.1 kg is an average across very different programmes.⁶

You do not need a gym to start. Standing up from a chair, step-ups on a sturdy stair and carrying the shopping all count as working against a load.

Protein at every meal gives that training something to build with

Training is the signal and protein is the material. A 2018 analysis pooled 49 trials with 1,863 healthy adults who did strength training for at least six weeks. Those who added protein to their diet gained an extra 0.30 kg of fat-free mass and an extra 2.49 kg on their one-rep max, the heaviest weight they could lift once.⁷ The extra protein made a little less difference in the oldest participants and more in people who already trained.

When you eat it matters too. In a small 2014 study, eight healthy adults ate the same daily protein for a week at a time, once spread evenly at about 30 g a meal and once mostly at dinner. With the even spread, their muscle made about 25% more new protein over 24 hours.⁸ It measured the rebuilding, not the size of the muscle, and it was short, but the authors point out that in many countries protein is skewed towards dinner while breakfast carries very little.

The Asian group sums it up the same way, naming exercise and nutritional support as the main things that help.² Protein leads, and the rest of the plate still counts. The carbs, the fat and the vegetables are all part of a meal that keeps you training.

Sarcopenia starts quietly, and two habits help

Muscle mass falls by roughly 3 to 8% each decade from about 30, and strength slips two to five times faster than size. Sarcopenia is the name for when strength, and then muscle, drop below a set line. The research points to strength training against a load, and protein spread across your meals. Eighty Thirty works out your daily protein and keeps count for you, so the food side of staying strong is taken care of every day. Start with our free macro calculator.