What Is a Body Composition Test?

What Is a Body Composition Test?

Move over, BMI! There’s a better way of measuring your health.

A body composition test is a much better way to help you reach your fitness goals.

If you’re reading this, it already means that you care about your health and fitness. You already know that you need to be active and eat a healthy, balanced diet. But how do you track your progress (other than your run-of-the-mill bathroom scale)?

Enter: the body composition test.

A body composition test provides a much more in-depth look into your physical makeup so you can get more detailed information about how your workouts are changing your body. Read on to find out what a body composition test is and why you need it.

What Is a Body Composition Test?

A body composition test basically measures how much of your body is lean muscle mass and how much is body fat. The test tells you what percentage of your body composition is composed of fat.

Why does this matter?

Your fat percentage determines your RMR, or resting metabolic rate. RMR is the rate at which your body’s metabolism functions at complete rest. In other words, the energy your body uses to circulate blood, fire neurons, digest food, and just exist. The higher the RMR, the faster you burn calories.

A body composition test analyzes two things: fat mass and fat-free mass. Your fat mass is pretty self-explanatory. This is the amount of fat in your body. Fat-free mass is everything else (i.e. your bones, muscles, organs, blood, and everything else).

Here at Ludus Actius, we believe that it’s important to see your own success, so we offer all of our members a free monthly body scan! This way, you’ll be able to track your progress and see your ratio of muscle to fat improving with every training session you attend.

How Is Body Fat Measured?

Doctors can use x-rays and MRIs to look at your bones and internal organs, but how do you know how much fat is in your body? Fitness experts have a few different ways of measuring body fat.

The most accurate methods involve an extremely high-tech piece of machinery to analyze your body fat percentage. DEXA scans and whole body plethysmography use x-rays and displaced air volume—respectively—to determine your body’s fat composition. However, these devices are very expensive, so it’s not easy to access them.

Weighing you underwater is also quite accurate, but involves immersing you in a pool of water. Not exactly quick or convenient.

Most gyms will use either calipers or bio-impedance analysis (or a combination of both).

Calipers work by pinching your skin in different areas on your body and measuring the thickness to determine how much fat lies underneath the skin. Bio-impedance devices work by sending a small current of electricity throughout your body. Because fat and lean mass conduct electricity differently, these devices are able to measure how much of your body is composed of fat.

How Is This Different From BMI?

BMI, or body mass index, is a simple calculation based on your height and weight. Odds are, if you’ve put any efforts into losing weight, you’ve calculated your BMI at some point and maybe even freaked out by your result.

But BMI is a very simplified analysis into your fitness level and is not an accurate estimate of your fat percentage. Your BMI is calculated using only two factors: your height and your weight. It does not—and cannot—determine how much of that weight is fat and how much of that weight is lean mass. If you’re lean but very muscular, your BMI may be skewed towards the high side (since muscle weighs more than fat).

Further, your BMI can’t distinguish between subcutaneous fat, which lies just underneath the skin, and visceral fat, which surrounds the organs (and is much more unhealthy).
By comparison, a body composition test is a much more accurate way to look at your physical progress.

Why Do I Need a Body Composition Test?

Knowing your body fat percentage can help you get a better idea of the amount of progress you’re making toward your fitness and nutrition goals.

As you begin to replace fat with muscle, your weight (and, therefore, your BMI) may not change much or at all. But seeing that your body fat percentage dropped from 25% to 20% will prove that the work you are doing is making a difference in your overall health and encourage you to continue.

Your monthly body scans also help us draft up the best course of action to get the results you want. You may want to lose fat, build muscle, or a combination of both. But you can’t know for sure unless you know where the starting line is.

A body composition test helps us locate that starting line so you can sprint toward the finish.


Although not directly related to BMI or a body composition test, we felt the urge to mention just how important nutrition is to your health and fitness goals.

Training is essential, but what you put in your body is just as important. Even the most rigorous workout will likely burn only 600 calories or so…an amount you can easily put back with a single meal.

At Ludus Actius, nutritional planning is included in your membership, because we understand how important it is to your fitness goals. We will teach you how to eat a healthy balanced diet and how/when you should indulge in life’s little pleasures.

Your goals are our goals.


BMI is the starting point point for most people looking to transform their bodies, but it’s just the beginning.

Finding your fat percentage through a body composition test is a much more accurate snapshot of your physical condition. By getting a clearer picture of where you are, you and your personal trainer have a better chance at working together to get where you want to be.

If you live in the Central Florida area and are interested in improving your physical fitness, give Ludus Actius a try. We are the most inclusive gym in Orlando and our Unlimited membership is satisfaction guaranteed.

If you have attended 12 or more classes in a month with no results within the first 6 months, we will refund your money. We are confident that our fitness classes combined with our body scan and nutritional planning will help you achieve the body you want!

Feel free to contact us so we can set you up with a 7-day free trial!