At Virtuagym, we calculate your energy need at rest, your total energy need, as well as give you daily calorie advice. Your Total Energy need is determined by the Basal Metabolic Rate (BMR) and the Physical Activity Level (PAL) value together. The BMR estimates the energy consumption of a person at rest and PAL value displays an image of the average degree of physical activity. Total energy need is the amount of kcal that need to be consumed in order to maintain your weight. Once the total energy need is established, calories are either added or removed from this value to help you achieve your goal. The formula we use for this calculation is presented below:
Total Energy Need = BMR X PAL
To calculate your BMR, Virtuagym has chosen the calculation method from James and Schofield (James and Schofield 1990). This method is widely used in science and provides a reliable estimate of the BMR.
Below you can find the data needed to calculate the BMR:
60.9 x kg - 54
15.3 x kg + 679
61.0 x kg - 51
14.7 x kg + 496
Gender - female, Age - 30 years old, Weight - 60 kg
BMR in this case will be 8.7 x 60 + 829 = 1351 kcal
This means that 1351 kcal are needed to maintain basic life functions and it excludes daily activities, workouts etc. BMR shows the lowest number of kcal that can be consumed on a long-term basis to keep the body alive. It is not advised to go below that value at any point in your diet routine.
Now that the BMR is calculated, it is important to estimate the PAL value. Each activity, even the smallest one, requires energy. A Metabolic Equivalent of Task (MET) is the ratio of energy expended during an activity to the energy expended at rest. If you want to learn more about MET of different activities and know how Virtuagym calculates calories you burn by exercising, click on this article. Calculating values of all your activities combined together during a 24 hour period gives the PAL value that Virtuagym uses in the final calculation of your total energy need.
At Virtuagym we divide activities into 'sleep', 'work' and 'leisure time' (with a total of 24 hours) to see how active you are daily.
MET values of different activities are presented below.
For work, a distinction is made between office work and standing work. The intensity of standing work may differ, therefore, this category distinguishes between light, average and heavy work. See the corresponding MET values that Virtuagym uses:
Office Work = MET 1.5
Light = MET 1.9
Average = MET 2.25
Heavy = MET 2.5
People differ in their leisure activities. That's why Virtuagym has chosen to categorize 3 different types.
The first type is not very active and spends time mainly lying and/or sitting. This person has a PAL value of 1.5 in his free time.
The Second type spends time just like the first type, mainly lying and sitting, but also does activities like shopping and light household tasks. The PAL value is therefore also slightly higher, namely 1.75.
The third type spends most of their free time with activities like groceries, cleaning, housework and more. The PAL value of this person in free time is 2.0.
It is important to know your type and select it correctly as this value is later used in the calculation of extra calories burned by exercise (article). If there are any changes in your sleep, work or lifestyle, you can always go back and create a new plan that will be adapted based on your new conditions.
If you sleep 8 hours a day, this means
8 (hours) x 0.9 (MET value) = 7.2
If you work 5 days a week 8 hours a day at the office
8 (hours) x 1.5 (MET value) = 12
If the remaining 8 hours you spend as type 1 (not very active)
8 (hours) x 1.5 (PAL value) = 12
31.2 is now divided by 24 hours to calculate the average of activity on a weekday (31.2: 24 = 1.3)
The weekend is calculated as 'leisure time' in this example you are a type 1 (not very active)
You sleep for 8 hours, therefore
8 (hours) x 0.9 (MET value) = 7.2
As there is no work, other hours are calculated as free time
16 (hours) x 1.5 (PAL value) = 24
31.2 is now divided by 24 hours to calculate the average of activity during the weekend (31.2: 24 = 1.3)
The average PAL of the week is 1.3
Calculating the Total Energy Need
BMR x PAL value = 1351 x 1.3 = 1756.3 kcal for maintenance
Similarly to this example, your total energy need is calculated. In your complete nutrition plan, you can see your BMR, total energy need as well as a daily calorie advice that is based on your goal. To find out how to create your nutrition plan, click on this article.