What is Muscle Mass and How to Measure It

Woman lifting weights

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Ever feel like you're spinning your wheels and going nowhere? When have set goals and working are working toward them, it can be hard to know whether or not you are making progress. That is a common feeling for people who have been consistently knocking out workouts but are not sure how to measure their results—especially with regard to strength.

But assessing your strength gains is not as difficult as you might imagine. With a little focused effort, you can start to see and understand the fruits of your labor. Here is what you need to know about how to measure your strength and muscle mass.

What is Muscle Mass?

There are three different types of muscle—skeletal, cardiac, and smooth muscle. Skeletal muscle is responsible for controlling movement and posture. Cardiac muscle consists of the heart, which pumps to keep you alive. Smooth muscle helps make up the gastrointestinal, urinary, reproductive, vascular, and respiratory systems.

You can voluntarily work and contract skeletal muscle; and because you can make it stronger and more efficient, it plays a big role in physical wellness. Plus, it also contributes to energy metabolism and storage.

How to Measure Muscle Mass

The more muscle you have, the better your body is able to handle things like aging and chronic disease that may come along with it like heart disease and type 2 diabetes. Acquiring more muscle requires putting your muscles under stress and tension by way of strength training and other forms of physical activity.

Combining a strength training routine with adequate nutrition, rest, and recovery, is the best way to gain muscle. Because you are likely already doing that, you may want to know how much muscle you already have. Try one of these methods for measuring muscle mass.

Take Regular Measurements

A good measure of progress is to use a measuring tape and measure the circumference around different body parts (think bicep, upper thigh, or chest). Taking once per month measurements in the same places will give you time to see a change.

The challenge with taking regular body measurements is that those numbers do not account for body fat and bone. That means sometimes you cannot be sure how much muscle you have under there.

Check Skinfold Thickness

Personal trainers often use skinfold calipers to measure their client's body fat. If you can determine how much body fat you have, you can subtract that number from your total body weight and determine your lean body mass—which consists of muscle, bone, skin, and organs.

Like body measurements, you will have to wait a few weeks (at least 4) before measuring again to see any quantifiable amount of change.

Although you can do these measurements on your own, it may be more accurate to have a trained professional perform the tests on you. If you can, have the same person take the measurements at regular increments to monitor change. By using the same person you can ensure greater accuracy.

Utilize Body Scans

The best way to know exactly how many pounds of muscle you have is to undergo a body scan using one of four techniques—bioelectric impedance (BIA), dual energy x-ray absorptiometry (DXA), computed tomography (CT), and magnetic resonance imaging (MRI). Of the four provided, DXA is the most cost-effective and easy to use standard for measuring muscle mass.

But without a prescription from a healthcare provider—or being a member of a wellness center that has a machine on hand—these measurements are not so easy to come by. Plus, they can be pricey - starting at around $99 for just one scan.

How to Track Your Progress

The thing about building muscle is that it takes a while. For that reason, measuring your progress is not only about how much muscle you have gained, but also about your strength, endurance, energy, and physical ability improvements. Gauge your progress with one of these ideas.

Keep a Strength Journal

Journaling can be useful in many facets of your life including physical wellness. In fact, studies show that incorporating reflective journaling is an effective strategy for accomplishing goals. Keeping a fitness journal is a great way to stay organized, plan your workouts, make changes where needed, and measure progress.

How to Track Progress

Here's how to use your fitness journal to see if you have gained strength.

  1. Plan your workouts in your fitness journal.
  2. Write down the exercises you want to perform and the rep scheme.
  3. Document the weight you used for each set during your workout.
  4. Include how you felt during the set.
  5. Review your journal at the end of the day or week to see how your strength has increased over time.

Take Regular Measurements and Photos

Because the number on the scale doesn't tell the whole story, regular measurements (skin fold, body fat, and body measurements) are a great way to see what is actually happening with your progress. When you document with photos, measurements, and body composition testing on a regular basis under the same conditions (first thing in the morning on an empty stomach every Friday, for example) you can clearly see if you are gaining muscle or not.

Calculating your body fat percentage can help you determine how much lean mass is on your body—and that includes muscle. If your body fat percentage is going down but your weight is remaining the same, or even going up, you are gaining muscle. Use a body fat calculator to get started.

Find Your 1RM

In the weight training world, your one rep max (1RM) is a measure of how much weight you can lift for one repetition on any given day. Your 1RM is a good indication of how strong you are.

You can use 1RM to determine strength gains by testing it regularly. It's important to remember that beginning lifters should wait until they have mastered the movement before testing their 1RM.

How to Test 1RM

  1. Use a spotter when attempting your 1RM.
  2. Perform a warm-up set that allows you to perform 6 to 10 reps, approximately 50% of your 1RM.
  3. Allow at least 1 minute rest.
  4. Perform a set that is about 80% of your max.
  5. Allow at least 1 minute rest.
  6. Increase the weight at 10% increments and attempt the lift with a spotter until you can no longer safely achieve the lift. That is your 1RM. You should reach your 1RM within 3 to 7 attempts.

Challenge Yourself

It is impossible to increase your strength without challenging your muscles. You cannot expect change from no change. For that reason employing a progressive training routine is essential for building strength and muscle.

In the same sense, if you are increasing the amount of weight you are using each week—or you are able to perform more reps with the same weight—you are making progress. So not only is a progressive workout routine important for making progress, it is also a great tool for measuring progress. If you are able to do more work than you were before, you are getting better!

Add Progression to Your Workouts

  • Increase the weight
  • Change the rep scheme
  • Add more sets
  • Reduce rest between sets
  • Increase time under tension
  • Add another strength training day to your week

A Word From Verywell

Making progress in the gym is exciting. Being able to lift more than you could before means you are doing something right and moving toward your physical wellness goals. But because it often takes time to see improvements, it is important to be patient with your results.

Trying to progress too quickly could lead to injury or overtraining, disrupting your routine and your goals. Instead, take time to document your workouts, measurements, and weights so you can see your progress over time.

Consult a healthcare professional before beginning any new workout routine. And if you are not sure how to safely reach your strength goals, a personal trainer or strength coach can help guide you.

Frequently Asked Questions

  • How do you know if you are gaining muscle?

    The best way to know if you're gaining muscle is by having your body fat percentage measured over time. Any improvements in body fat percentage and increases in weight likely means you are gaining muscle.

  • How many reps should you do to build muscle?

    You can build muscle using a variety of rep schemes. In general, heavier weights and lower rep schemes (6 to 2 reps) are good for muscle hypertrophy.

  • What should you eat for muscle growth?

    Nutrition for muscle building requires adequate calories and a high protein diet. Avoid skimping out on any one macronutrient (protein, carbohydrates, or fat). To determine your calorie range needs, multiply your body weight by 16 and 18.

8 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Shoshana Pritzker RD, CDN, CSSD, CISSN
Shoshana Pritzker RD, CDN is a sports and pediatric dietitian, the owner of Nutrition by Shoshana, and is the author of "Carb Cycling for Weight Loss." Shoshana received her B.S in dietetics and nutrition from Florida International University. She's been writing and creating content in the health, nutrition, and fitness space for over 15 years and is regularly featured in Oxygen Magazine, JennyCraig.com, and more.