The Truth about your Metabolism

Which weighs more, a pound of muscle or a pound of fat? Ok, just kidding, a pound is a pound.

But you would be surprised to know how many times I have been asked that question. Generally that question or others like it, refer to the old adage about muscle weighing more than fat and muscle increasing metabolic rate. There is no doubt about it, the more muscle you have, the higher your resting metabolic rate will be. The same however can be said about weight in general; the more you weigh the higher your resting metabolic rate is. Similar to many other nuggets of knowledge that we often take as "fitness gospel", the trail of misinformation is often lined with money. So, how overstated, understated or misrepresented is the muscle-metabolism link?

 

Buy this, build muscle and ignore the disappointment

Imagine you are watching TV and some sculpted, somewhat irritating, energizer bunny type guy or gal is riding some odd contraption doing hip thrusts while somehow speaking with perfect clarity. You know the type I am talking about. My favorite lately is the guy on the Teeter Hang Ups commercial. He is like 70 years old and swings upside down and back upright while simultaneously talking to the camera without pausing for a single second. It's crazy. Anyway, the hip thrusting energizer bunny is saying something like, "Burn fat and build muscle! For each pound of muscle you gain you will burn 50 extra calories a day!" Wow, fifty extra calories day is pretty spectacular. That means if you build a measly five pounds of muscle, you will burn 250 extra calories a day just sitting around. Sign me up!

 

If you browse around the internet for a little while you will see numerous articles that claim you will burn 50-60 extra calories for each additional pound of muscle you build. This does sound pretty appealing but does it add up? Let's take a look at an average female (according to science's AVERAGE, not society's real average). The average 5' 6" 125 pound female will have about 43 pounds of skeletal muscle. So about 36% of an average female's body weight is muscle tissue. If each pound of muscle does indeed burn 50 calories per day that would mean 43 pounds of muscle will burn about 2150 calories a day. Consider for a second that this does not yet include the metabolic activities of the heart, lungs, liver, brain or additional calories expended through exercise. Needless to say, skeletal muscle does not burn 50 calories a day at rest. What can you expect from a few extra pounds of muscle?

 

At rest the actual caloric expenditure per pound of skeletal muscle is roughly 5-6 calories per day. Using our female subject, we can expect her resting metabolic rate to be somewhere around 1300 calories a day. Now, let's say each pound of her skeletal muscle burns 5.5 calories a day at rest. This would put total calories expended by her skeletal muscle at 215 calories a day. This represents about 20% of resting metabolic rate. If this same individual added five extra pounds of muscle tissue, this would expend a whopping 25 extra calories a day. I know this sounds a bit disappointing but there is more to the story.

 

After the fact

What does it take to gain considerable amounts of muscle tissue? Strength or resistance training is generally regarded as the best way to gain muscle tissue. Additionally, high intensity exercise such as interval training or strength training can impact resting metabolic rate for up to 24-48 hours after exercise has been completed. Some of these increases in resting energy expenditure can be as high as 7%. Again, considering the resting metabolic rate of the female subject mentioned previously, a 7% increase in resting metabolic rate would amount to an extra 91 calories. If intense exercise such as strength training is performed several days a week, in addition to other activities or exercise you may involved in, the temporary increases in resting metabolic rate associated with strength training can certainly add up. Steady state cardiovascular exercise, while the caloric expenditure the exercise is fairly high, any increase in resting energy expenditure is short lived. 

 

One place people often go wrong, especially women, is the intensity and type of the strength training they participate in. In order to increase resting energy expenditure, muscular strength and to some extent muscle size, it requires more than performing a few five pound bicep curls. You need to perform exercises that involve large muscle groups such as the quadriceps, hamstrings, chest and back

 

It’s always worth mentioning that women should not be concerned with "bulking" as a result of lifting too much weight. For reasons such as caloric restriction and the typical female hormone profile, most women simply can't "bulk up" to begin with.

 

Different stages = different results

I always like to touch on the fact that you can expect different results depending on the level of caloric restriction you are currently under. As caloric intake increases the further active you become, so will the level of exercise you can tolerate. If you are just starting, take it slow, do what you can and set yourself up for success by creating realistic goals.

 

Long-Term Success

Next to simply controlling caloric intake, regular physical activity is the most powerful tool at your disposal. While exercise may not be best at actually causing weight loss, its ability to help you maintain weight loss is second to none. Whether it is the calories expended during a spin on the bike, a good strength training session or those five pounds of extra muscle you have developed, together they act as a powerful set of resources to control weight and ensure long-term success.

Until Tomorrow!
Keep healthy, keep safe and keep going!

Have an awesome day!

♥Fit~NOW~Girl♥