Does Muscle Weigh More Than Fat?

A common fitness and biology myth is that muscle weighs more than fat. This is incorrect when examined from two different elements of exercise science. It should be understood that weight and mass are two different concepts. These terms are used interchangeably, but obviously do not have the same definition. Once these terms are understood it can help contribute to the understanding why muscle cannot weigh more than fat. Another factor that effects body composition is metabolism. Besides that the endocrine system plays a role and the hormones it produces. When engaging in a consistent exercise regimen, lean body mass can increase depending on genetic body type. Fat tissue will decrease, but it will appear as if weight has gone up. This can be easily explained by scientific concepts.

      Mass can be defined as ” the fundamental property which measures the amount of matter contained within an object.” One of the properties of an object with mass is to resist being moved. Objects with mass tend to resist a change in speed or direction. This phenomenon of physics is known as intertia. This explains why when a person runs at high speeds it is difficult for a person to change direction immediately. Weight can be defined as ” the total force exerted on a body due to gravitation.” Objects attract one another by gravitation, which is a fundamental force of the universe. To prevent confusion , science has used the units similar for weight on Earth and mass. Dayana Cadeau when competing weighed 150 lbs( 68.03 kg). If she were to be on a space ship her mass would not disappear from her body. She would be weightless, due to the face gravitation is not acting on her body. Gravitation is proportional to the mass and declines with distance.

 The Earth’s gravitational force is acting on her body. The only way to break free from it is to achieve escape velocity. Force is measured in newtons (N). Mass is measured in kilograms (Kg). When people use the phrase ” I want to lose weight” it should be I want to reduce the total mass of fat composition on my body. That would be more precise that losing weight, because the only way that would happen is if the Earth’s gravitation cease to exist. These concepts are the basics of classical physics. Newtonian mechanics falls under this branch. Physics mostly attempts to understand matter  and its relation to the universe. Understanding these definitions of mass and weight  explain why muscles weighing more than fat is not scientifically sound.

      There is the consideration of space used on the human body . Matter takes up space and the body is matter. Muscle is much more dense compared to fat. Muscle can take as much as four -fifths of space. This also relates to size of a person. A taller and larger person has the ability to sustain more total mass, because the skeleton would be larger compared to a smaller person. This also explains why a people of the same height and weight may wear different clothing sizes. It depends on the amount of body fat percentage and how it is distributed on the body. There also is a consideration in density. Density describes the mass per unit volume. It appears that muscle in a single unit may have more density if compared in a same size unit to fat. The average density of fat is 0.9 g/ml compared to 1.1 g/ml of muscle. Muscle can in liter form be 1.6 kg (2.3 lbs)compared to 9 kg (1.98 lbs). This does not mean a muscular person will weigh more than a fat person. These averages vary depending on if the person is extremely lean or morbidly obese. A kilogram  of muscle will still be equal to a kilogram  of fat.

It is clear here who would weigh more. The muscular person will not have more mass compared to the fatter person. 

This can be deceiving, but it does not automatically the muscular person would weigh more. That also explains why the body mass index is not entirely accurate measure of healthy weight. A short muscular person could be inaccurate placed in the obese range simply because their mass in not in that height bracket.

         When discussing fat and muscle there is the consideration of metabolism. The endocrine system and hormones also play a role in this process. Estrogen and testosterone function differently. Muscle has the ability to burn seven to ten calories daily per pound. Fat can only achieve two to three calories daily per pound. Testosterone has an anabolic effect on the muscular system allowing for greater muscular hypertrophy. Men produce more, which explains why it is easier for them to lose weight and gain muscle. Women do produce testosterone, in lower levels and estrogen increases body fat. Even the most muscular woman still carries close to 8% body fat. Muscle still can be a great burner of  calories. Getting engaged in a strength training regimen can help burn at least for to six calories a day. It is possible under a consistent exercise regimen to gain at least five pounds of  muscle mass in three months depending on morphic body type. This requires consistent use of the muscles through exercise to increase net caloric effect. It is plausible that in a span of months( under a training regimen) this can amount to 30 calories per day. The basal metabolic rate describes the calories you burn during rest. Oddly enough, this amounts to 75% of the calories you burn in a day. It is good for one’s health to keep body fat low and remain active. Heart disease, type 2 diabetes, and cancers are associated with weight related problems.Understanding metabolism and how it works with hormones can help prevent such ailments.

         Muscle can make you gain mass and increase weight. This is lean body mass, but it is not harmful. Weight that is gained through excessive eating, gland or hormonal abnormalities, or being too sedentary can be hazardous to health. Diet is essential to any training regimen. Weigh loss can be effective with diet, but with exercise it will be permanent. This reveals that different forms of training can produce varied results. If one wants to merely lose fat, without lean body mass gain, it can be done.

Losing mass in terms of fat is demonstrated here.
Here is a demonstration of gaining muscle mass in exchange for fat.

What this comes down to is what method is used and what are the particular fitness goals. This is the difference between exercise to gain weight ( muscle mass) and exercise to lose ( fat tissue). Strength training is emphasized when trying to gain or make weight. Majors muscle groups have to be exercised including arms, legs, chest, and abdomen. This includes working each muscle group in an exercise session. Besides training rest is also pivotal. The body needs time to repair the muscle tissue that will be rebuilt into a stronger muscle. Losing fat tissue rather than gaining muscle mass has another technique. It has been common to either emphasize aerobics or cardiovascular exercise a method. However, recently it seems that solely doing these exercises may not be enough to be effective. Using both weight training and some cardiovascular exercise has been found to be more efficient.The increase in lean body mass does not mean a person failed in their fitness goal.

       Muscles based on what is known about exercise physiology and physics cannot weigh more than fat. Weight being the function of gravitation explains this. The term that should be accurately employed is mass. Density also is another concept that gets used interchangeably  with these terms. There are numerous fitness myths that are spread around. This one tends to be another common one. Limited knowledge could sabotage some individuals. A woman seeking to reduce body fat may try strength training and be alarmed at what the scale indicates. It is not showing that you gained fat tissue, but lean body mass. They may quit a method that is effective without realizing it . Full comprehension between the definitions of mass and weight can help end the confusion. Weight and mass are not the same entity.

Further Reading

Kent, Linda. “A Pound of Fat Vs. a Pound of Muscle.” LIVESTRONG.COM. Leaf Group, 21 Apr. 2015. Web. 28 Dec. 2016. <;.

Sheldon, Lyenne. “Can Gaining Muscle Make You Gain Weight?” LIVESTRONG.COM. Leaf Group, 13 May 2015. Web. 28 Dec. 2016. <;.

Barnes-Svarney. The Science Reference Desk. New York : The Stonesong press, 1995.

Does Muscle Weigh More Than Fat?

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