What is Metabolism?

You’ve probably had a friend that can eat all the food and never gain weight. You know, “that skinny b*tch with a “fast” metabolism.” (I kid! No skinny shaming, muscle shaming, or fat shaming will be happening here!)

You might also be connected enough to your body to notice fluctuations in your own metabolism. For example, if you stop working out for too long you might be more likely to put on some extra juice (aka fat ūüėČ).

But why? What’s up with metabolism anyway?

Technically, metabolism is all of the biochemical reactions in your body.¬† It’s how you take in nutrients and oxygen and use them to fuel everything you do.

John Mayer was right. Your body truly is a wonderland! It has the ability to grow, heal, and generally stay alive.  Without this amazing biochemistry you would not be possible.

Metabolism includes how the cells in your body enable:

  • Activities you can control (e.g. physical activity etc.).
  • Activities you can’t control (e.g. heart beat, wound healing, processing of nutrients & toxins, etc.).
  • Storage of excess energy for later.

When you put all of these mechanisms together it’s easy to see how metabolism can vary from person to person and also fluctuate over time.

Which brings us to the metabolic rate.

Your¬†metabolic rate¬†is the amount of energy your body uses measured in calories. In other words, it’s how fast your metabolism is working.

The calories you eat can go to one of three places:

  • Work (exercise and other activity).
  • Heat (from all those biochemical reactions).
  • Storage (excess ‚Äúunburned‚ÄĚ calories stored as fat).

Basically, the more calories you burn for work or creating heat, the easier it is to lose fat and keep it off because there will be fewer excess calories to store for later.

There are a couple of different ways to measure metabolic rate.¬† One is the resting metabolic rate¬†(RMR) which is how much energy your body uses when you’re not being physically active.

The other is the total daily energy expenditure (TDEE) which includes both the resting metabolic rate as well as the energy used for work (e.g. exercise) throughout a day.

So what affects your metabolic rate?

A lot my friend!

Hormones – I’m sure you’ve heard of the thyroid gland.¬†Your thyroid is located at the front of your throat. It releases hormones to tell your body to ‚Äúspeed up‚ÄĚ your metabolism.¬† Generally, the more thyroid hormone there is the faster things will work and the more calories you’ll burn.

Body Size –¬†How big you are counts too! Larger people have higher metabolic rates. But it’s not just about the size of your body, it’s also about your body composition as well.

Body Composition – As¬† a personal trainer I typically encourage my clients to focus on building muscle through resistance training. Muscles that actively move and do work require more energy than fat does. This means that the more lean muscle mass you have, the more energy your body will burn resulting in a higher metabolic rate even when you’re not working out! Heck yeah!

Exercise – To move that beautiful body your muscles require energy (calories) as fuel. Therefore, getting in your fitness can help to temporarily increases your metabolic rate.

Food –¬†The type of food you eat also affects your metabolic rate. Your body actually burns calories to absorb, digest, and metabolize your food.¬† This is called the thermic effect of food¬†(TEF).

Understanding how your body metabolizes foods differently can help you make meal choices that will kick your metabolism up a notch.

Fats, for example increase your TEF by 0-3%; carbs increase it by 5-10%, and protein increases it by 15-30%.  By trading some of your fat or carbs for lean protein you can slightly increase your metabolic rate. 

This is fabulous on so many levels because not only does your body need protein to help your muscles grow, it burns more energy to digest it. #winning

(Check out a metabolism boosting recipe here.)

By working your muscles and feeding them what they need they can help you transform and maintain a lean strong body.

Mind-body Connection РAnd last but definitely not least, research shows that things like stress and lack of sleep decrease your metabolic rate. Getting in the habit of meditating daily and getting  7 Р9 hours of sleep per night can help improve your mind-body connection and your metabolism.

Your body is beautifully complex so we are really just scratching the surface of metabolism and how different variables can work to increase (or decrease) your metabolic rate.

And although some of these factors are beyond your control, others are not. What habits can you create to help you reach your health and fitness goals? 


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