Lesson Activity

Calculate your basal metabolic rate (BMR). You can use Google to find a calculator, or use this one here: www.bmrcalculator.com.au


When it appears we are doing nothing, standing here for example, we are actually using lots of energy.  Thinking, breathing, pumping blood around, the gut working, using muscles to hold us up and so on, there is actually a lot going on.  So all day we are using energy and burning calories even if we don’t exercise. This is called our basal metabolic rate or BMR.

It actually accounts for between 60-75% of the daily energy we use.  Energy is represented by calories or kilojoules which I will describe in more detail in another video.  So let’s say if I eat a food with 100 calories, and my BMR burns 50 calories an hour, it would take me 2 hours to use those calories, or that fuel or energy.

Our metabolic rate is determined by a number of factors, like our genetics, our body mass and composition, our age and two master hormone glands called our thyroid gland in our neck and hypothalamus in our brains.

BMR topically declines by 1–2% per decade after age 20 mostly due to the loss of muscle.  And when it comes to body composition the higher our body weight the higher our BMR and the more muscle we have the higher our BMR.

It is very easy to go online now and calculate what your BMR is and I recommend you stop and do it now.  You can see that you might burn 1500 calories just doing nothing. The importance of knowing this is when we look at how much energy, fuel or calories we are putting into our body we can easily see if we are putting more in than we are burning through our BMR.

The good news is the BMR does most of the work for us, and we just need to get below that level.

The bad news is that as we lose weight our BMR actually slows down, so it gets harder to keep losing weight.  When we reduce our food and energy intake during dieting our BMR decreases to a greater extent than expected, this is a phenomenon termed ‘adaptive thermogenesis’.  That is why lots of people see good results for a few months and then their success ends. Its because the body actually reduces the BMR to stop you from wasting away, it is a survival mechanism.  There are many ways to get around this so don’t worry, we shall cover them in detail in a later video.