What is sarcopenia?
Sarcopenia is a disease of the skeletal muscles. In sarcopenia, muscle mass and strength are reduced. This mainly occurs in the elderly but can also occur at a younger age. Sarcopenia is defined as a progressive and generalized skeletal muscle disorder associated with an increased risk of adverse outcomes, including falls, fractures, physical disability, and mortality.
Symptoms of sarcopenia include:
- Difficulty getting up from a chair or bed
- Difficulty carrying groceries or lifting something heavy
- Difficulty climbing stairs
- Decreased strength in arms and/or legs
- No longer being able to kneel or bend over
- Falls
Effects of sarcopenia include:
- Increased risk of falls and fractures
- Decreased ability to perform daily activities
- Mobility disorders
- Reduced quality of life
- Loss of independence
- Increased risk of death
There are two major different forms of sarcopenia, primary and secondary. In primary sarcopenia, aging is the only cause. When you get older, the balance between muscle building and muscle breakdown changes. Muscle building decreases (this phenomenon called anabolic resistance) and muscle breakdown increases. The result is a loss of muscle mass in the elderly. Secondary sarcopenia may have other causes – in addition to aging – such as: diseases (cancer, organ failure), inactivity, inadequate energy and/or protein intake (malnutrition).
Sarcopenia is not always visible on the outside. Two people with the same body weight can still have a different amount of muscle mass. Someone can therefore look overweight even though their muscle mass is too low. This is called sarcopenic obesity. This is not a great diagnosis to have as the treatment is quite intense for someone with this diagnosis. As well as building up the volume and strength of the muscles, the adipose tissue (fat cells in connective tissue) has to be decreased.
How do you know if you have sarcopenia?
How to measure muscle strength?
An easy test which you can even perform at home is to see if the person can lift a 5 kg weight (you can use a bag of groceries or 5 one-liter packages of drinks).
Another measurement of muscle strength is the sit-stand test from a chair. The cut-off value is > 15 seconds for standing up 5 times without using arms.
Muscle strength can also be measured with a handgrip strength meter (with a cut-off value for men < 27 kg and women < 16 kg).
Exercise is vital for muscle mass and strength
Whether you suffer from sarcopenia or not, it is important to realize that exercise is essential for building and maintaining muscle mass. If the muscles are not used, muscle mass decreases rapidly.
The other way around also applies: if the muscles are used, muscle mass increases. And that can be done well into old age!
There are different forms of movement, including:
- Strength training: increases muscle strength and muscle mass. Weightlifting is of course an example of strength exercise. Jumping, climbing stairs and dancing also belong to this group.
- Endurance training: improves oxygen intake and fitness. Cycling and running are examples of endurance activity.
- Balance exercises. These are static and dynamic exercises aimed at improving balance while a person is standing or moving, such as standing on one leg or picking up an object from the ground.
Ideally, all three types of exercises should be performed weekly.
For maintenance of muscle mass, strength exercises at least twice a week are recommended. This as well as the general advice to have a moderate level of physical activities on a daily basis.
There are no contraindications for strength training other than that the load must be built up slowly to prevent injuries.
Dietary protein importance
Consuming sufficient protein and spreading it well throughout the day is very important for maintaining muscle mass and strength.
The Nutrition Centre of the Netherlands does not recommend a higher protein intake for the elderly population. The recommended protein intake in the Netherlands for the majority of the population is 0,83 g per kg body weight. Vegans are strongly advised to consume 30% more protein. However, some authorities and expert groups suggest protein recommendations for the elderly in the range of 0·94–1·3 g/kg/d.
If you belong to the category of elderly people, you can start optimizing your protein intake by aiming for 1 gram of protein per kilogram of your body mass. This is easy to calculate. If your weight is 75 kg, you need to consume 75 g of protein per day.
The recommendation is to spread the protein intake more or less evenly over the main meals (breakfast, lunch, dinner). In practice, this means that you have to consume 25 g of protein per meal. Therefore, a croissant (4 g of protein) with a glass of orange juice (1 g of protein) is not an optimal breakfast!
It is probably good to know that dietary strategy works synergistically with exercise. This means that one plus one equals three in this case!
Take-home messages
- Adequate protein intake and exercise are both necessary to maintain muscle strength.
- Your weight does not say anything about your muscle mass and strength.
- The older you get, the more you have to exercise.
- The older you get, the more conscious you have to be about your protein intake.
- It is never too late to start eating properly and exercise!