If you’ve ever stepped on the scales and felt disappointed by the number looking back at you, you’re definitely not alone. But here’s something I often tell my clients: your weight is only one small piece of the puzzle.
Two people can weigh exactly the same, yet have completely different body compositions, energy levels and overall health. That’s because our bodies are made up of much more than just body fat. Muscle plays a huge role too.
Understanding your muscle mass can help you see your progress in a much more positive and realistic way, especially if your goal is to become stronger, healthier and more confident rather than simply losing weight.
So, what is muscle mass?
When we talk about muscle mass, we’re usually referring to skeletal muscle. These are the muscles attached to your bones that help you move, lift, walk, climb the stairs and carry out everyday tasks.
Unlike the muscle in your heart or digestive system, skeletal muscle responds to exercise and nutrition. It can become stronger, grow over time and, if we don’t use it, gradually decrease as we get older.
What does muscle mass percentage actually mean?
Muscle mass percentage is simply the proportion of your body weight made up of muscle.
For example, if you weigh 70 kg and 28 kg of that is muscle, your muscle mass percentage would be 40%.
While that sounds straightforward, it’s important not to get too caught up in the exact figure. Different body composition scales use different formulas, so your results can vary depending on the machine you’re using.
Instead of chasing a specific percentage, it’s much more useful to look at whether your muscle mass is staying the same or gradually improving over time.
Why is muscle so important?
Many people think building muscle is only for athletes or people who spend hours in the gym. In reality, muscle is something we all need, regardless of age or fitness level.
Having healthy muscle helps you:
- Feel stronger in everyday life
- Improve balance and coordination
- Support your joints
- Maintain good posture
- Stay active as you get older
- Make everyday tasks feel easier, from carrying shopping to climbing stairs
Muscle also uses energy to maintain itself, although its impact on metabolism is often smaller than social media would have you believe. The biggest benefit is how it supports your overall health, mobility and independence throughout life.
Does muscle naturally decrease with age?
Unfortunately, yes.
From around our thirties onwards, we gradually begin to lose muscle if we don’t actively work to maintain it. This happens slowly at first but tends to speed up later in life.
The good news is that this isn’t something you simply have to accept. Regular strength training and eating enough protein can make a real difference, helping you stay strong and active well into older age.
Is there an ideal muscle mass percentage?
This is one of the questions I get asked most often.
The honest answer is no.
There’s no single “perfect” muscle percentage because we’re all different. Your age, sex, genetics, lifestyle and activity levels all influence how much muscle you naturally carry.
Rather than comparing yourself to someone else online, it’s far more helpful to compare yourself to… well, yourself.
If you’re getting stronger, feeling fitter, recovering well and your body composition is improving over time, you’re moving in the right direction.
How can you measure your muscle mass?
Many people now own smart scales that estimate muscle mass using a method called bioelectrical impedance.
They’re quick, affordable and useful for spotting trends, but they’re not perfectly accurate. Your hydration levels, what you’ve eaten and even the time of day can all affect the reading.
If you’re using a smart scale, try to measure yourself under similar conditions each time so you can track progress more consistently.
For the most accurate assessment, clinics can offer DEXA scans, which provide a much more detailed breakdown of your body composition.
How can you build or maintain muscle?
The great news is that you don’t need to spend every evening in the gym.
Strength train regularly
The NHS recommends adults include muscle-strengthening activities at least twice a week.
That could be:
- Lifting weights
- Resistance bands
- Pilates
- Bodyweight exercises
- Heavy gardening or manual work
The key is to challenge your muscles consistently and gradually increase the difficulty over time.
Eat enough protein
Protein gives your body the building blocks it needs to repair and maintain muscle.
Include a source of protein with each meal, such as:
- Chicken or turkey
- Fish
- Eggs
- Greek yoghurt
- Cottage cheese
- Beans
- Lentils
- Tofu
- Tempeh
For people who regularly exercise or are looking to build muscle, protein needs may be higher than the general UK recommendation, so it’s worth discussing your individual requirements with a qualified professional.
Keep moving
Strength training is important, but so is staying active throughout the day.
Walking, cycling, swimming and other forms of movement all support your overall health and help keep your body functioning well.
Don’t forget recovery
Muscles don’t grow while you’re exercising—they adapt afterwards.
Getting enough sleep, managing stress, staying hydrated and allowing time to recover are all part of looking after your muscles.
The bottom line
Your muscle mass is just one measurement. It doesn’t define your health or your progress.
Instead of obsessing over a number on the scales or your body composition report, ask yourself a few simple questions.
Am I getting stronger?
Do I have more energy than I did a few months ago?
Can I do everyday tasks more easily?
Am I building habits I can actually stick to?
Those answers will usually tell you far more than any scale ever could.
At the end of the day, building and maintaining muscle isn’t about looking a certain way. It’s about feeling strong, staying healthy and giving your body the support it needs for years to come.
Inside Out Wellbeing 