The Copenhagen Sarcopenia Study: lean mass, strength, power, and physical function

The Copenhagen Sarcopenia Study is an important study because it looked at muscle mass, muscle strength, muscle power, and physical function across the entire adult lifespan, rather than focusing only on people who were already elderly.

Link to study: https://pubmed.ncbi.nlm.nih.gov/31419087/

Purpose

The study’s main goal was to establish age- and sex-specific reference values for sarcopenia-related measures in healthy Danish adults aged 20–93 years. The researchers wanted to understand when different aspects of muscle function begin to decline with age and to provide local reference values that could be used when assessing sarcopenia.

They studied 1,305 participants from the Copenhagen City Heart Study and measured:

  • Muscle mass: total and appendicular lean mass using DXA

  • Muscle strength: handgrip strength

  • Muscle power: leg-extension power

  • Physical function: 30-second sit-to-stand and walking speed

General findings

The most interesting finding is that different aspects of muscle performance deteriorate at different times.

  • Muscle power appears to decline earliest. Leg-extension power and performance on the 30-second sit-to-stand test were already significantly lower beginning around age 50.

  • Walking speed and handgrip strength declined later. Maximal walking speed showed meaningful reductions from roughly age 60, while habitual walking speed was reduced particularly after 70.

  • Muscle mass declined later still. Measures such as appendicular lean mass remained relatively preserved until approximately the 70s, although the relationship with age was gradual rather than an abrupt threshold.

  • Men generally had greater muscle mass, grip strength, and leg power than women across the age groups.

  • The decline in physical performance accelerated with advancing age, meaning that aging wasn't simply associated with a uniform, linear loss of function.

The big takeaway

A useful way to think about the study is:

Power → strength/function → muscle mass decline in that approximate sequence.

In other words, you can lose the ability to produce force quickly before you lose a large amount of muscle tissue. This is important because everyday activities such as getting out of a chair, climbing stairs, or preventing a fall often depend heavily on muscle power, not simply how much muscle you have.

That finding supports the modern view of sarcopenia as being about more than just "low muscle mass." Muscle strength and physical performance are clinically important components as well.