Muscles vs. Fat. One of the most frequently asked questions to our Personal Trainers: "Do muscles really weigh more than fat?". The question always accompanies a pair of hopeful eyes, because that number on the scale sometimes keeps us very busy. And whilst you are having a great time working with your trainer but don't see any change on the scale (yet), you start wondering what's going on.
In order to answer the question properly, it is useful to first establish that we are talking specifically about mass per volume. Because one kilo always remains one kilo, so the density of the muscle tissue and the fat tissue is what matters.
Density of (muscle) mass
We look at the density per cubic centimeter (cm3).
In the table below you can see the difference in density of water, muscle mass and fat mass.
Mass | Density per cubic centimeter |
Water | 1 gram |
Fat | 0,9 gram |
Muscle | 1,06 gram |
If you take out the calculator and calculate the difference, you will see that muscle mass is about 18% heavier then fat mass. Of course these are averages, no person is exactly the same. For example, your origin influences the density of your lean body mass. In general, people with Latino or African backgrounds have a slightly higher density of muscle mass.
The fact that muscle mass is 18% heavier than fat mass means that it is correct that if you lose fat, but build more muscle mass, your weight will go up. However, your fat percentage goes down. So even though the number on the scale doesn't seem to change, you are often very satisfied with the changes you see in your body.
Do you gain weight and do you have the idea that this is not because your muscle mass is increasing? Book a free trial session and talk about it with your trainer. Together you can discuss what could be the cause and how you can change this.
Gaining muscle mass is often an aesthetic goal for many people, but did you know that there are other benefits to it, such as for your metabolism? Read all about this in our blog “More muscle mass = higher metabolism” .
Would you like the best possible workout, tailored to your body and your goals? Our trainers are specially trained for this and come to your location when it is most suitable for you. This can be at home, or on a location outside, such as during your lunch break at the office or in a park nearby. Our trainers are certified, and speak both English and Dutch. And especially for women we have ‘Ladies Only’. Sports coaching for women, given by women. Also for guidance during a pregnancy or after childbirth.