Regardless of if you are sitting on your couch waiting tv, spinning up a storm, or getting a pump on, you are always using energy. Your METABOLIC RATE is the rate at which your body uses energy. When we exercise, our bodies require more energy and our metabolism speeds up to supply it. Increasing your metabolism will help you burn calories, replace fat with muscle and give you more energy… who doesn’t want that! This is why many people try to boost their metabolism… but I will come to that later. Your metabolism is a combination of physical and chemical processes known as anabolism and catabolism.
Think of Anabolism is as “the builder”. This is the constructive phase within your metabolism process, in which the body builds body cells for growth and repair. The opposite is Catabolism or “the breaker”. Catabolism is the destructive phase, where substances are broken down into smaller, more simple compounds to make energy. This is essential for a proper functioning body. Together Anabolism and Catabolism as used to distribute nutrients which are then absorbed into the blood after the digestive process.
Simple as that.
Three factors contribute to your metabolic rate (metabolism):
1. The basal metabolic rate– the rate your body uses energy for vital body functions ** which I will discuss below**
2. The rate you burn energy during physical activity
3. The rate you use energy during digestion of food
Estimates of energy expenditure at rest and during exercise are found through how much oxygen you consume and its caloric equivalent. Ever heard of a VO2? VO2 is a measure of whole-body oxygen consumption. Your average Joe, uses .3L of oxygen per minute or 18L of oxygen per hour or 432L of oxygen per day. Through knowing your VO2 you can then go ahead and calculate your caloric expenditure. Keep in mind that at rest (ex. sitting on your couch) your burn a mixture of carbs and fats, contributing to a RER (Respiratory Exchange Ratio… don’t worry about this too terribly much) of .80 or 4.80 calories burnt per litre of oxygen consumed.
Oxygen Exchange
Number crunching time. Want to know how many calories per day you burn at rest? Here is what to do. Take the litres of oxygen consumed per day and multiple by the amount of calories used per litre of oxygen consumed. Sounds confusing right?
Calories per Day Burnt = litre of oxygen consumed per day X calories used per litre of oxygen
So remember that your average Joe uses 432 L of oxygen per day, multiplied by 4.80 calories burned per litre of oxygen consumed… and volia… Joe burns 2,074 calories per day.
Read Part 2 for more information on your BMR and contributing factors!
