What do you think of when you hear the word “metabolism?” Many people associate the word metabolism with weight loss, weight gain or their own body fat. In many ways, metabolism affects all of these things. Metabolism, however, isn’t just turned on and off in our bodies like a light switch. There are several factors that affect the different ways metabolism works for each of us.

So, what exactly is metabolism?

Metabolism is simply the process in which the body converts foods, liquids and other substances into energy. We all know that metabolism helps our body break down food, but it also helps heal injuries and remove toxins from the body. The three things that have the greatest impact on metabolism are nutrition, hydration and activity. The better we are at maintaining optimum and appropriate levels of food, water and exercise, the more efficient our metabolisms become. If we become negligent in these areas, weight gain usually follows.

Your metabolism is comprised of four different factors. Individually, these factors really weigh in on how efficiently our bodies use energy.

1. Resting Metabolic Rate or RMR (very similar to Basal Metabolic Rate)
In a nutshell, your RMR is the amount of energy your body burns over the course of a day in order to sustain life. Imagine your RMR as what’s required of your body if you were to lie in bed all day long without voluntarily moving a single muscle. This measurement accounts for roughly 60 to 70 percent of your entire metabolic rate.

2. Sedentary Activity Level
You’ve decided to get out of bed, get ready for work or do some normal day-to-day activity. The moment you start moving around, whether it’s getting up to brush your teeth or taking a brisk walk to catch the train, you’re tapping into Sedentary Activity Level.

3. Purposeful Activity Level
For the most part, Purposeful Activity Level is exercise. Whether you’re lifting weights, running on the treadmill or intentionally increasing your activity level beyond what would be considered normal routine, you’ve given this measurement a bit of a jumpstart.

4. Thermic Effect of Food
The moment anything with nutritional value enters your digestive tract (solid or liquid), you’re revving up your metabolic rate. Typically, the less fit you are, the lower your Thermic Effect of Food will be. With a range of 4 to 10%, an elite athlete has a higher burn rate and a couch potato runs lower.