What Is Metabolism?

What is metabolism? That word is thrown around a lot these days. You know that if yours is too slow, you gain weight. But what exactly does metabolism mean?

What is metabolism?

Well technically “metabolism” is the word used to describe all of the biochemical reactions in your body. It’s the process of taking in nutrients and oxygen, and using them them to fuel everything you do. Metabolism is the measurement of how much energy it takes to fuel your body.

Metabolism includes how the cells in your body:

  • Allow activities you can control (physical activity).
  • Allow activities you can’t control (heartbeat, wound healing, digestion, filtering toxins, etc.).
  • Allow storage of excess energy for later.

So when you put all of these processes together into your metabolism, you can imagine that these processes can work too quickly, too slowly, or just right.

Which brings us to the “metabolic rate”.

Metabolic rate

This is how fast your metabolism works and is measured in calories (yup, those calories!).

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

  • Work (exercise and other physical activity).
  • Heat (from all those biochemical reactions).
  • Storage (leftover “unburned” calories stored as fat).

As you can imagine, the more calories you burn as work the easier it is to lose weight and keep it off because there are be fewer “leftover” 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 measures both the resting metabolic rate as well as the energy used for “work” (e.g. exercise) throughout a 24-hour period.

What affects your metabolic rate?

Lots of things affect your metabolism.

One of the most important things is your thyroid. This gland at the front of your throat releases hormones to tell your body to “speed up” your metabolism. The more thyroid hormone you produce, the more calories you’ll burn.

thyroid and metabolism

Chronic stress can destroy your thyroid function. Exercise, healthy nutrition, and stress management will go a long way towards keeping your thyroid functioning properly.

But thyroid is not the only thing that affects your metabolic rate.

Eating often enough to keep your blood sugar levels stable will help keep your metabolism churning.

Eating a combination of protein and high-fiber carbohydrates (like vegetables) every 3-4 hours should do the trick. When you go too long without food, your brain goes into starvation mode and will lower your metabolism in order to conserve energy.

How much muscle you have is a big factor.

Muscular people have higher metabolic rates. Muscles that do work need more energy than stored fat does. So the more lean muscle mass you have, the more energy your body will burn, and the higher your metabolic rate will be — Even when you’re not working out!

This is exactly why weight training is recommended as a part of a weight loss program. Because you want muscles to be burning those calories for you 24 hours a day.

When people lose weight by dieting, their metabolic rate often slows down — which you don’t want to happen. You definitely want to offset lowered calorie intake with increased muscle. If you decrease your calories too much — without increasing your metabolism with weight training — your brain will lower your metabolism in an attempt to conserve energy.

Aerobic exercise only temporarily increases your metabolic rate. Your muscles are burning fuel to move, so they’re doing “work”. But after you’re done with cardio, you don’t get that metabolic “afterburn” like you do when you train with weights.

Some research shows that your metabolic rate (i.e. your hourly calorie burn) is elevated for as long as 72 hours after a hard strength training workout. So if you want to lose weight, get off the treadmill and pick up the dumbbells instead!

personal training helpIf you want help putting together a solid strength training and nutrition program to increase your metabolism, contact Basics and Beyond for a no-obligation discussion of options. We offer personal training and nutrition in Nashville, or online.