'Use it or Lose it!' - How to Maintain Your Muscle & Prevent Sarcopaenia

Feb 05, 2024 8:00am

It’s a saying that has become cliché, but it is one that provides a useful mantra for those of us getting older. Many good things accompany the ageing process - wisdom resulting from decades of life experience, less back, neck and face pain, less sweat and even increased sexual satisfaction! (1, 3, 4) But there are certainly undesirable changes too. As physiotherapists, perhaps the most life altering of these changes is the loss of muscle mass that often accompanies ageing. In particular, this article will take a look at the severe loss of muscle mass termed Sarcopaenia.

Muscle Mass and Ageing

As we get older, our bodies become anabolically resistant. Anabolism is the process of building up tissues such as muscle, so increased resistance to this process - resulting from hormonal changes during ageing, makes it much harder to retain or build muscle tissue. Anabolic resistance is hardest hitting for those who are largely sedentary. This is because physical activity, in particular, resistance training is one of the best ways to build and retain muscle! Physically inactive adults lose around 3-8% of their muscle mass per decade after the age of 30, and this process accelerates after age 50. So a sedentary person at age 80 can expect to have lost around 40-50% of the muscle mass they had at age 20 (2). Such a large decline in muscle mass will lead to many sedentary older adults being diagnosed with Sarcopaenia.

 

What is Sarcopaenia?

Sarcopaenia comes from the ancient Greek for ‘a poverty of flesh’. People with sarcopaenia have severely reduced muscle mass and strength, to the point where they have trouble with everyday tasks. It is NOT a normal part of aging but is more prevalent than you might think. Sarcopaenia is diagnosed based on these three criteria:

  1. Low muscle strength - you may have difficulty with everyday tasks such as standing from a chair or climbing stairs.

  2. Low muscle mass - a health professional can identify whether you have a significant deficit in muscle tissue quantity simply by observation. This can be more accurately measured via DXA scan, however this is not required.

  3. Poor physical performance - a physiotherapist can identify this using tests such as a 5x sit-to-stand test where we measure how long it takes to rise from a chair 5 times.


Another feature of sarcopaenia is ‘marbling’. This is fat infiltration in and around muscle fibres and is a marker of low muscle tissue quality. Muscles with a high degree of fat infiltration are less healthy, and tend to be less effective at producing force.

 

What causes Sarcopaenia?

We have seen that older adults naturally lose a lot of muscle mass over their adult years, but it is the imbalance of factors that cause muscle breakdown (catabolic) over factors that cause muscle build up (anabolic) that cause someone to become so anabolically resistant that they develop sarcopaenia. Some of these factors are outlined in the table below.

Table 1: Anabolic and catabolic factors of sarcopaenia (2)


Why is it important to avoid sarcopaenia?

First and foremost sarcopaenia takes a massive toll on an individual’s functional capacity. This is the pool of energy that a person has to give to each of their everyday tasks - if getting out of a chair is a maximal effort, the task will take a lot more out of someone than those who find it easy. The same can be said for showering, cleaning, cooking, doing the groceries, playing with grandchildren…. The list goes on!

The other big impact of sarcopaenia is on our physiological reserve. This is the physical superannuation or money in the bank that we keep for tough times. When someone is hospitalised due to an injury or illness, they tend to lose muscle mass and strength. If someone is sarcopenic, they only have to lose a very small amount to lose what independence they had left - making it much more likely that they will be discharged to a care facility rather than their own home. 

In addition, sarcopenia is a strong indicator of all-cause, cardiovascular and cancer mortality, so clearly losing muscle mass is something we should all be trying to avoid.


What can you do to avoid Sarcopaenia?

To prevent or treat sarcopaenia, we need to increase the anabolic factors relative to the catabolic ones, as per table 1! Importantly, we need to increase the amount of muscle stimulating contractions (resistance training) and increase the dietary intake of protein in order to supply the muscles with the building blocks to create muscle tissue. Resistance training should meet or exceed the minimum physical activity guidelines of at least 2 strength based sessions per week, challenging all the major muscle groups through a full range of motion. However, the dosage is important and should be individualised on a person by person basis. The evidence suggests that higher exercise volumes show a greater muscle synthesis in those with sarcopaenia than lower volumes. For example - doing 6 sets of squats will likely provide a greater response than performing 3 sets. This principle of greater dosage applies to dietary protein too. 

The evidence suggests that older adults should consume between 1.2-1.6g per kg of lean body weight in order to maximise muscle protein synthesis. Let's look at the protein requirements of someone who weighs 60kg. On average, that person's lean body mass will be about 75% of their total weight - which is about 45kg - so they should be aiming to consume between 54 and 72g of protein each day. This can take a variety of forms depending on the person’s personal preference (see table 2 for ideas!) This is far greater than the recommended dietary intake of 0.8g per kg of bodyweight, but has been shown to be safe in healthy individuals. (Note: A more rigorous cost-benefit analysis of protein intake should be undertaken in those with chronic kidney disease who are sarcopaenic.)

 

Table 2: Protein content of various foods


How to get started with resistance training?

According to the Australian Bureau of Statistics, only 1 in 5 adults 55+ meet the physical activity guidelines of 2 strength sessions each week. That means a big portion of people are missing out on the benefits and setting themselves up for weakness and reduced independence later in life.

We understand it can be daunting getting started, especially if you haven't done strength training before. That's where our team of experienced Be Mobile physiotherapists comes in. You can get started building your strength and your physical nest egg today by joining our free online platform today.

Join the Be Mobile Platform today!

 

Summary… 

We have seen that sarcopaenia is a severe loss of muscle mass, strength and function, resulting in increased risk of hospitalisation, mortality and loss of independence. Thankfully, you can maintain and build muscle mass with sufficient resistance training and dietary protein intake!

And remember… if you don’t use it, you lose it! 

 

 

References

  1. Anderson, R., & Kenney, W. (2021). Effect of age on heat-activated sweat gland density and flow during exercise in dry heat | Journal of Applied Physiology. Journal of Applied Physiology. Retrieved 29 November 2021, from https://journals.physiology.org/doi/abs/10.1152/jappl.1987.63.3.1089.

  2. Baraki, A. (2021). Sarcopenia Lecture w/ Dr. Austin Baraki. Youtube.com. Retrieved 29 November 2021, from https://www.youtube.com/watch?v=wJBqBDZoSvQ.

  3. Stephen Thielke, M. (2021). Aging: Are these 4 pain myths complicating care?. PubMed Central (PMC). Retrieved 29 November 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4356472/.

  4. Trompeter, S., Bettencourt, R., & Barrett-Connor, E. (2012). Sexual Activity and Satisfaction in Healthy Community-dwelling Older Women. The American Journal Of Medicine, 125(1), 37-43.e1. https://doi.org/10.1016/j.amjmed.2011.07.036