Sarcopenia: diagnosis and resistance training in the elderly

A woman in her early seventies comes to a routine visit accompanied by her daughter. The complaint is vague: she walks more slowly, takes a while to get up from the armchair and has started using the handrail on any staircase. The daughter thinks it is "just her age". The patient weighs the same as always, and so nobody thought of muscle loss.

The scene illustrates the central problem of sarcopenia. The disease was long neglected and little treated in clinical practice, partly because of the difficulty of deciding what to measure, how to measure it and which cutoffs to use (Cruz-Jentoft, 2019). Stable weight misleads, because muscle can be replaced by fat without the scale changing.

This text shows how the revised European consensus organized the diagnosis, why grip strength became the first sign to look for and what the evidence says about resistance training, the only treatment with a strong recommendation in international guidelines.

Key points

• The revised European consensus (EWGSOP2) came to treat low muscle strength as the main feature of sarcopenia (Cruz-Jentoft, 2019).
• The proposed sequence is find, assess, confirm and grade severity, in a path called F-A-C-S (Cruz-Jentoft, 2019).
• The EWGSOP2 grip cutoffs are less than 27 kg in men and less than 16 kg in women (Cruz-Jentoft, 2019).
• In a systematic review of cohort studies, sarcopenia was associated with higher mortality, with a pooled odds ratio of 3.6 (Beaudart, 2017).
• The international clinical practice guideline strongly recommends prescribing resistance-based physical activity to treat sarcopenia (Dent, 2018).
• Protein enters as a conditional recommendation, and vitamin D and anabolic hormones were left without a recommendation for lack of evidence (Dent, 2018).

Summary

• What changed in the definition of sarcopenia
• How to make the diagnosis: the F-A-C-S path
• Strength and mass: what each measure says
• Why sarcopenia matters
• Resistance training: the treatment with the strongest evidence
• How to prescribe in practice
• Protein, vitamin D and medications
• How NEXO helps train this reasoning
• Frequently asked questions
• Take-home messages

What changed in the definition of sarcopenia

The first European definition, published in 2010, was widely used around the world and helped identify and care for people with sarcopenia (Cruz-Jentoft, 2019). In 2018, the group met again to incorporate the evidence accumulated over the decade, and the result is the consensus known as EWGSOP2 (Cruz-Jentoft, 2019).

A disease of the muscle, and not only of aging

EWGSOP2 describes sarcopenia as a muscle disease, a "muscle failure", rooted in adverse changes that accumulate over a lifetime (Cruz-Jentoft, 2019). The consensus recalls that it is common in older adults, but it can also appear earlier (Cruz-Jentoft, 2019).

This change in language has a practical consequence. When sarcopenia is seen as a disease, and not as an inevitable part of age, it comes to deserve screening, diagnosis and treatment.

Strength before mass

The main novelty was to put low muscle strength ahead of the other criteria. In EWGSOP2, low strength identifies probable sarcopenia; low muscle quantity or quality confirms the diagnosis; and low physical performance indicates severe sarcopenia (Cruz-Jentoft, 2019).

The logic is clinical. Strength predicts poor outcomes better than mass, and measuring strength is simple and cheap (Cruz-Jentoft, 2019). The American SDOC consortium reached a similar conclusion by another path: lean mass measured by densitometry was not associated with adverse outcomes in community-dwelling older adults, with or without adjustment for body size (Bhasin, 2020).

Primary and secondary

The consensus separates primary sarcopenia, attributed mainly to aging, from secondary sarcopenia, linked to other causes, and considers this division useful in practice (Cruz-Jentoft, 2019). In secondary sarcopenia, looking for the underlying disease is part of the treatment. Inactivity, bed immobility, malnutrition and chronic diseases are on this list, and the patient with cancer-related weight loss, as discussed in the text on malnutrition and cachexia in gastric cancer, is a frequent example.

Prevention throughout life

EWGSOP2 sums up prevention in one sentence: maximize muscle in youth and early adulthood, maintain it in middle age and minimize loss in old age (Cruz-Jentoft, 2019). The sentence is a reminder that muscle in advanced age depends on earlier decades, and that the moment to start strength training is always the present.

How to make the diagnosis: the F-A-C-S path

EWGSOP2 recommends a four-step path, find, assess, confirm and grade severity, for use in clinical practice and in research (Cruz-Jentoft, 2019). The acronym is F-A-C-S, from Find, Assess, Confirm, Severity (Cruz-Jentoft, 2019).

Find: the SARC-F questionnaire

To find cases, the consensus suggests the SARC-F questionnaire, which collects typical signs of sarcopenia from the patient (Cruz-Jentoft, 2019). The ICFSR international guideline suggests screening older adults from age 65 once a year or after major health events, using gait speed or SARC-F (Dent, 2018).

SARC-F has a known limitation. In a meta-analysis of 20 studies, pooled sensitivity ranged from 27 to 77 per 100 people with the disease, depending on the diagnostic criterion used, and specificity ranged from 63 to 91 per 100 (Lu, 2021). The authors concluded that, given its practicality and high specificity, the questionnaire remains useful for screening (Lu, 2021).

In practice, a negative SARC-F lets some cases slip through. When clinical suspicion is strong, as in the patient at the opening, it is worth going straight to the strength measurement.

Assess: grip strength or chair stand test

The second step is to measure strength. The consensus recommends handgrip, measured with a dynamometer, or the five-times chair stand test without using the arms, which serves as an indirect measure of thigh strength (Cruz-Jentoft, 2019). When the hand does not allow the measurement, as in advanced arthritis or after a stroke, isometric torque methods of the lower limb are an alternative (Cruz-Jentoft, 2019).

Low strength alone is enough to speak of probable sarcopenia and to start intervening (Cruz-Jentoft, 2019). The consensus also recalls other causes of weakness to consider, such as depression, stroke, balance disorders and peripheral vascular disease (Cruz-Jentoft, 2019).

Confirm: quantity or quality of muscle

Confirmation requires showing low muscle quantity or quality. EWGSOP2 lists dual-energy X-ray absorptiometry (DXA) and bioimpedance in clinical practice, and MRI and CT in research (Cruz-Jentoft, 2019). Calf circumference, with a cutoff below 31 cm, can serve as a substitute when no other method is available (Cruz-Jentoft, 2019).

Grade severity: physical performance

The last step measures performance. A gait speed of up to 0.8 m/s indicates severe sarcopenia by EWGSOP2 (Cruz-Jentoft, 2019). The consensus also accepts the SPPB battery, the Timed Up and Go test and the 400-meter walk (Cruz-Jentoft, 2019).

The table sums up the EWGSOP2 cutoffs.

Test	Cutoff	Source
Grip strength	Less than 27 kg in men and less than 16 kg in women (Cruz-Jentoft, 2019)	EWGSOP2 (Cruz-Jentoft, 2019)
Chair stand	More than 15 s for five repetitions (Cruz-Jentoft, 2019)	EWGSOP2 (Cruz-Jentoft, 2019)
Appendicular skeletal muscle mass (ASM)	Less than 20 kg in men and less than 15 kg in women (Cruz-Jentoft, 2019)	EWGSOP2 (Cruz-Jentoft, 2019)
ASM divided by height squared	Less than 7.0 kg/m² in men and less than 5.5 kg/m² in women (Cruz-Jentoft, 2019)	EWGSOP2 (Cruz-Jentoft, 2019)
Gait speed	Up to 0.8 m/s (Cruz-Jentoft, 2019)	EWGSOP2 (Cruz-Jentoft, 2019)
SPPB	Up to 8 points (Cruz-Jentoft, 2019)	EWGSOP2 (Cruz-Jentoft, 2019)
Timed Up and Go	20 s or more (Cruz-Jentoft, 2019)	EWGSOP2 (Cruz-Jentoft, 2019)
400 m walk	Test abandonment, or 6 min or more (Cruz-Jentoft, 2019)	EWGSOP2 (Cruz-Jentoft, 2019)

Strength and mass: what each measure says

Handgrip is the exam that delivers the most information for the least effort. EWGSOP2 describes low grip strength as a strong predictor of longer hospital stays, more functional limitation, worse quality of life and death (Cruz-Jentoft, 2019).

Grip as a vital sign

Population data reinforce this idea. In the UK Biobank, with 502,293 participants aged 40 to 69, each 5 kg less of grip strength was associated with higher all-cause mortality, with a hazard ratio of 1.16 in men and 1.20 in women (Celis-Morales, 2018). The same analysis found an association with cardiovascular, respiratory and cancer mortality (Celis-Morales, 2018).

These numbers come from an observational study and show association, without proving that increasing grip strength prolongs life. Even so, they help explain why strength became the starting point of the diagnosis.

Cutoff points change according to the consensus

The reference value depends on who defines it. EWGSOP2 uses less than 27 kg in men and less than 16 kg in women, values based on normative data from the United Kingdom (Cruz-Jentoft, 2019). The SDOC consortium, with another methodology, arrived at less than 35.5 kg in men and less than 20 kg in women as discriminators of slow gait speed (Bhasin, 2020).

The European consensus recognizes that its recommendations focus on European populations and use references from healthy young adults (Cruz-Jentoft, 2019). The global prevalence review lists at least six classifications in use, including the European, Asian and international groups, each with its own cutoffs (Petermann-Rocha, 2022). SDOC warns that the performance of a grip cutoff can vary with age, ethnicity and underlying disease (Bhasin, 2020).

For those who provide care, the consequence is simple. It is worth using the consensus adopted in the service, recording which one was used and interpreting the result in the context of the patient, without treating the cutoff as an absolute boundary.

Why mass alone misleads

Muscle mass is the hardest part to measure. Devices, methods and equations vary, and anthropometry alone is a poor measure of muscle, despite being used to assess nutritional status (Cruz-Jentoft, 2019).

In the SDOC analysis, lean mass by DXA did not independently predict adverse outcomes, unlike grip strength and gait speed (Bhasin, 2020). The panel concluded that weakness and slowness should be part of the definition of sarcopenia (Bhasin, 2020).

Physical performance at the bedside

Performance tests are simple, but they require care. EWGSOP2 notes that it is not always possible to apply them, for example when dementia, gait or balance disturbance interfere with the test (Cruz-Jentoft, 2019). Gait speed, on the other hand, is considered quick, safe and very reliable (Cruz-Jentoft, 2019).

Why sarcopenia matters

Sarcopenia is linked to outcomes that weigh on the patient and the family. In a systematic review of cohort studies, 11 of 12 studies assessed mortality, and mortality was higher among people with sarcopenia, with a pooled odds ratio of 3.596 (Beaudart, 2017).

Function, falls and hospitalizations

The same review showed an association with functional decline, with a pooled odds ratio of 3.03 in six studies (Beaudart, 2017). Falls and hospitalizations were also more frequent in the studies that assessed them, although the number of studies was small (Beaudart, 2017). The effect on fractures and length of stay was less clear (Beaudart, 2017).

Falls are the point where sarcopenia meets the emergency department. A frail older adult who falls from standing height can have a serious injury with few signs, as shown in the text about falls from standing height in older adults.

How many people have sarcopenia

Prevalence depends on the criterion. In a meta-analysis with 151 studies and 692,056 people, prevalence ranged from 10 to 27 per 100, depending on the classification and the cutoff (Petermann-Rocha, 2022). Severe sarcopenia ranged from 2 to 9 per 100 (Petermann-Rocha, 2022).

The difference between criteria even appears between the sexes. With EWGSOP2, prevalence was higher in men, 11 versus 2 per 100, while with the international group criterion it was higher in women, 17 versus 12 per 100 (Petermann-Rocha, 2022). The authors concluded that the lack of a single criterion makes it hard to compare studies (Petermann-Rocha, 2022).

Hospitalization as an accelerator

Muscle loss speeds up in situations of rest. Days in bed during a hospitalization reduce the stimulus the muscle receives. Mobilization in the ward also helps prevent delirium, as discussed in the text on what to do at the bedside in hypoactive delirium.

The same reasoning appears in an extreme scenario. In orbit, without the load of body weight, astronauts lose bone and muscle, and countermeasures include exercise, as the text on space medicine shows. Muscle responds to load, on Earth and beyond it.

Resistance training: the treatment with the strongest evidence

The international clinical practice guideline for sarcopenia, from ICFSR, strongly recommends prescribing resistance-based physical activity as treatment (Dent, 2018). A strong recommendation, by the GRADE method, indicates that the benefits clearly outweigh the risks (Dent, 2018).

What the reviews in older adults show

The Cochrane review on progressive resistance training in older adults included 121 trials with 6700 participants (Liu, 2009). In most, training was done two to three times a week at high intensity (Liu, 2009). The effect on muscle strength was large, with a standardized mean difference of 0.84 in 73 trials (Liu, 2009).

The gains reached function. There was a modest improvement in gait speed, of 0.08 m/s in 24 trials, and a moderate to large effect on the time to rise from a chair, in 11 trials (Liu, 2009). The improvement in overall physical capacity was small but significant (Liu, 2009).

What the studies in people who already have sarcopenia show

A 2023 network meta-analysis gathered 42 trials with 3728 people with sarcopenia, with a median age of 72.9 years and median follow-up of 12 weeks (Shen, 2023). With high or moderate certainty, resistance training, with or without nutrition, and the combination of resistance with aerobic and balance training were the most effective interventions for quality of life (Shen, 2023).

For grip strength, the combination of resistance and balance training with nutrition was the most effective, with a mean gain of 4.19 kg (Shen, 2023). For gait speed, resistance and balance, with or without nutrition, yielded 0.16 m/s, above the minimum important difference of 0.1 m/s (Shen, 2023).

Safety

Safety is often the patient's and family's doubt. In the Cochrane review, serious adverse events were rare, and no serious event was directly attributed to exercise (Liu, 2009). The authors call for caution because adverse events were poorly recorded in many trials (Liu, 2009).

Musculoskeletal complaints, such as joint pain and muscle pain, appeared in several studies that monitored them prospectively (Liu, 2009). In practice, these complaints are often a reason to review the load and technique with the patient.

Why intensity matters

The ICFSR exercise guideline states that sarcopenia requires high-intensity resistance training for the best adaptation (Izquierdo, 2021). The same document describes resistance training as the central treatment for sarcopenia, since medications have not shown a clear benefit (Izquierdo, 2021).

How to prescribe in practice

The ICFSR exercise guideline recommends resistance training two to three times a week, starting with one to two sets and progressing to two to three sets of 8 to 12 repetitions (Izquierdo, 2021).

Starting and progressing

For those who have never trained, the guideline proposes using loads equivalent to 50, 60, 70 and then 80 in every 100 parts of the maximum load for one repetition in the first four training days, over one to two weeks (Izquierdo, 2021). In the following sessions, the perceived exertion scale guides the increase in load, keeping the effort between hard and very hard, from 15 to 18 on the original Borg scale (Izquierdo, 2021).

Meta-analyses cited by the guideline show that progressing to 70 to 80 parts in every 100 of the maximum load produces more strength than staying at light or moderate loads (Izquierdo, 2021). In Borde's review, total training time and intensity had a significant effect on strength, and the largest effect appeared with 70 to 79 parts in every 100 of the maximum load (Borde, 2015).

Volume and frequency

Borde's review, in healthy older adults, found the best isolated effect on strength with two weekly sessions, two to three sets per exercise and seven to nine repetitions per set (Borde, 2015). The largest effects appeared in the longest programs, of 50 to 53 weeks (Borde, 2015).

The practical message is that the gain continues over time. A program of a few weeks may show an initial result, but strength is maintained with regular training and no end date.

Power and balance

The loss of power with age is especially fast, and that is why the ICFSR guideline supports including power training, with fast and strong contractions, whenever possible, in active and frail older adults (Izquierdo, 2021). The guideline also recalls that combining balance and resistance training is the most effective intervention to reduce falls (Izquierdo, 2021).

In the network meta-analysis, resistance combined with balance was one of the most effective combinations for gait speed (Shen, 2023). For the patient in the opening, this means adding balance exercises to strength training from the start.

When perceived exertion does not work

The ICFSR guideline advises using perceived exertion scales when heart rate does not reflect intensity, as in people who use a beta-blocker or a pacemaker (Izquierdo, 2021). If cognitive impairment prevents use of the scale, the observer can assess breathing, the ability to speak, sweating and facial expression (Izquierdo, 2021).

Where to train

Machines, free weights and elastic bands serve for resistance training, according to the Cochrane review (Liu, 2009). The choice depends on the patient's access and safety. For those with major limitations, starting with supervision from a physiotherapist or physical education professional helps adjust the load and the technique.

Adherence

The best prescription is the one the patient follows. Asking what the person wants to do again, such as climbing stairs without help or carrying groceries, helps give meaning to the training. For those who are ambivalent, motivational interviewing offers a path, and starting from the patient's agenda avoids imposing goals that make no sense to them.

Protein, vitamin D and medications

The ICFSR guideline conditionally recommends that the clinician consider protein supplementation or a protein-rich diet for older adults with sarcopenia (Dent, 2018). A conditional recommendation indicates that many professionals would choose the intervention, but others would not, because of uncertainty about the balance between benefits and burdens (Dent, 2018).

What nutrition adds to training

In the network meta-analysis, adding nutritional intervention to exercise had a greater effect on grip strength than exercise alone, with a similar effect on the other measures of physical function (Shen, 2023). Nutrition therefore complements training, without replacing it.

Vitamin D and hormones

The ICFSR considered the evidence insufficient to say whether vitamin D supplementation alone works in older adults with sarcopenia (Dent, 2018). The guideline also considered the evidence insufficient to recommend anabolic hormones (Dent, 2018). The exercise guideline reinforces that medications have not yet shown a clear benefit in sarcopenia (Izquierdo, 2021).

Beware of excess

A diagnosis of sarcopenia can become a gateway to repeated body composition tests and supplements without an indication. For most patients, strength, gait and a training program guide more than successive tests. The concept of quaternary prevention helps weigh what each test adds.

Back to the case

In the patient from the opening, the F-A-C-S path would start with clinical suspicion and with a grip strength measurement or the chair stand test (Cruz-Jentoft, 2019). With low strength, probable sarcopenia is already present and training already begins (Cruz-Jentoft, 2019).

The initial prescription would be resistance training two to three times a week, with load progression guided by perceived effort, plus balance exercises (Izquierdo, 2021). The conversation about food and protein would come next (Dent, 2018). Measuring gait speed would help grade severity and track the response (Cruz-Jentoft, 2019).

How NEXO helps train this reasoning

In NEXO, the case of the day is fictional, with a real clinical presentation and up to six progressive clues, and you propose the diagnosis by searching for the ICD-10 code.

The limits of using the game are described on the NEXO economy page. If you research clinical reasoning teaching, the page for researchers explains how to get in touch. Professionals who write or review cases find information under curation and under creators, and institutions can learn about the proposal on the partnerships page. For the most frequent reasons for consultation, see the most common codes in primary care.

Frequently asked questions

What is sarcopenia?

It is a muscle disease, marked by loss of strength and of muscle mass or quality, that accumulates over life and is common in older adults (Cruz-Jentoft, 2019).

What is the first test to do?

A strength measurement, by handgrip or by the five-times chair stand test (Cruz-Jentoft, 2019). Low strength already defines probable sarcopenia (Cruz-Jentoft, 2019).

What are the grip cutoffs?

Per EWGSOP2, less than 27 kg in men and less than 16 kg in women (Cruz-Jentoft, 2019). Other consensus statements use different values, such as SDOC, with less than 35.5 kg and less than 20 kg (Bhasin, 2020).

Is SARC-F enough to rule out sarcopenia?

It is specific but not very sensitive, with combined sensitivity between 27 and 77 out of every 100 people with the disease, depending on the criterion (Lu, 2021). With clinical suspicion, it is worth measuring strength.

Which exercise treats sarcopenia?

Resistance training, with a strong recommendation from the international guideline (Dent, 2018). Combining resistance with balance and aerobic exercise also improves quality of life (Shen, 2023).

How often should one train?

Two to three times a week, progressing to two to three sets of 8 to 12 repetitions (Izquierdo, 2021).

Is strength training safe for older adults?

Serious adverse events were rare in the Cochrane review, and no serious event was attributed directly to exercise (Liu, 2009).

Does protein supplementation help?

The guideline recommends considering protein conditionally (Dent, 2018). Added to exercise, nutrition increased grip strength more than exercise alone (Shen, 2023).

Is there a drug for sarcopenia?

So far, no drug has shown a clear benefit, and the evidence is insufficient for anabolic hormones and vitamin D alone (Dent, 2018).

Take-home messages

• Sarcopenia is a muscle disease, not just part of aging.
• Low strength is the first sign to look for and already allows probable sarcopenia to be named.
• The F-A-C-S path organizes the diagnosis into find, assess, confirm and grade.
• Cutoffs vary by consensus and region; record which one was used.
• SARC-F is specific but lets cases slip through; with suspicion, measure strength.
• Resistance training is the treatment with a strong recommendation.
• Intensity should progress to high loads, guided by perceived effort.
• Protein complements training; vitamin D and hormones were left without a recommendation.

Play the case of the day on NEXO.

References

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2. Bhasin S, Travison TG, Manini TM, et al. Sarcopenia Definition: The Position Statements of the Sarcopenia Definition and Outcomes Consortium. J Am Geriatr Soc. 2020. PMID 32150289. DOI 10.1111/jgs.16372.
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8. Celis-Morales CA, Welsh P, Lyall DM, et al. Associations of grip strength with cardiovascular, respiratory, and cancer outcomes and all cause mortality: prospective cohort study of half a million UK Biobank participants. BMJ. 2018. PMID 29739772. DOI 10.1136/bmj.k1651.
9. Lu JL, Ding LY, Xu Q, et al. Screening Accuracy of SARC-F for Sarcopenia in the Elderly: A Diagnostic Meta-Analysis. J Nutr Health Aging. 2021. PMID 33491031. DOI 10.1007/s12603-020-1471-8.
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