An article by exercise physiologist, Jennifer Smallridge

Did you know that the human body has more than 600 muscles? Depending on where they are located, muscles are responsible for so many vital functions - walking, lifting, pushing, pulling, blinking, even the beating of your heart and the process of digesting food requires specialised muscles to do the job! 

 The size and function of your muscles are a good indicator of health, which does change over the lifespan, as we will learn below. 


Children and teenagers 

For young people, the size of the lean muscles gives a good indicator on whether a child is getting enough nutrition in their diet. At this stage of life, before puberty, males and females will generally have similar muscle mass in their bodies. After puberty, the sex hormone testosterone promotes an increase in muscular size and strength for males in particular, however it is important for all adolescents to stay active and ensure that they are building a strong baseline for the years to come.  


Alarmingly, we start losing 3-5% of our muscle mass per decade after we hit the age of 30. It is thought that this corresponds with the natural decline of testosterone in the body.  With this in mind, it is best to encourage young adults to get as fit and strong as possible. After this turning point, however, it is never too late to maintain or build on the muscles you have.  

The clinical loss of muscle mass is called sarcopenia, and can lead to an increased risk of falls and bone fractures, as well as a loss of function and independence. Having low muscle mass also puts people at an increased risk of dying from all causes - just another good reason to use it before you lose it! In fact, there are very few health conditions (including type 2 diabetes, heart disease, strokes and Parkinsons Disease) which would not benefit significantly from increasing muscle mass.  

Science has proven that whether we are building muscle, maintaining what we have, or preventing further loss; progressive resistance/strength training is key. This is a style of exercising where you use your major muscles against resistance (bands, bodyweight, dumbbells, kettlebells) and gradually increase the repetitions or the weight as you get fitter and stronger. This way the muscular system is constantly challenged and having to adapt. An Accredited Exercise Physiologist can help design a program that suits your needs.  

Whether or not you are engaging in strength training, protein intake is also essential for feeding our muscles. An Accredited Practicing Dietitian can help you reach your protein goals.  


Muscle strength around the home 

Muscles aren’t only build in gyms! You may already unknowingly be strengthening up by your everyday activities. Picking up grandchildren, walking up hills, carrying the groceries, squatting up and down in the garden and walking up stairs can all promote muscle strength and function.   

If you are seeking targeted results, a targeted exercise program is best. It generally takes 6-8 weeks to see and feel a difference in your strength, so find something that you love to do and be sure to do it often.  




Cruz-Jentoft, A.J. and Sayer, A.A., 2019. Sarcopenia. The Lancet, 393(10191), pp.2636-2646. 

Webber, C.E. and Barr, R.D., 2012. Age-and gender-dependent values of skeletal muscle mass in healthy children and adolescents. Journal of cachexia, sarcopenia and muscle, 3(1), pp.25-29. 

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