Physical Activity and Calorie Expenditure
Physical activity is a very significant component of our daily lives.
Everything that we do contributes to our physical activity. Activities such as walking, running, cleaning, playing games, etc.
Based on the frequency of the activity, intensity, and duration, one can classify physical activity levels.
Knowing your physical activity level will help you modify your lifestyle to obtain maximum health.
Whenever we work, we burn calories. This is very significant in measuring and knowing your physical activity level.
The table below shows Physical Activity and Calories used per minute for some of the major activities we carry out daily.
|For 57Kg person||For 70Kg person||For 84Kg person|
|Walking (17min/ mile)||4||5||6|
|Walking (15min/ mile)||4.5||5.6||6.7|
|Walking (13min/ mile)||5||6.2||7.4|
|Running (11.5 min/mile and cross country)||9||11.2||13.3|
Source: Harvard health publishing
Calories are sometimes confused for fats. These however do not mean the same thing.
Calories represent the amount of energy released when your body breaks down food that you eat.
The body uses up these calories as they are being produced. If the calories are not used up at the same rate with which they are produced, you are likely going to put on some weight.
Similarly, if your body uses up more calories than you consume daily, you are likely going to lose some weight.
Some classes of food and the calories released per gram are given below:
- Fat – 9 calories per gram
- Carbohydrate – 4 calories per gram
- Protein – 4 calories per gram
- Water – 0 calories per gram
How to know the number of calories you need to maintain your weight
Knowing the number of calories you need to maintain your weight is essential. This will help you moderate your food and activity level.
To do this, you will need to find your Basal Metabolic Rate (BMR).
BMR is the amount of calories or energy you use when you are not performing any activity.
It is determined separately for males and females.
You will need to know the following to calculate your BMR
- Weight in kilograms
- Height in centimetres. ( If you know your height in meters, multiply by 100 to convert it to centimetres)
- Age in years.
Follow the link and input the values to know your BMR
The result you get will be in calories/day. The formula used is the Harris – Benedict formula.
Take note and determine the lifestyle group you belong to based on your physical activity level
- Sedentary Lifestyle
If you carry out little or no exercise in the day, your physical activity level is 2
- Lightly Active
If you do little exercise or sports 1 – 3days in a week, your physical activity level is 375
- Moderately active
If you do moderate exercise or carry out sporting activities for 3 – 5 days in a week, your physical activity level is 55
- Very active
If you do hard exercise or sports for 6 – 7 days in a week, your physical activity level is 725
- Extra active
If you do very hard exercise or job more frequently and for over 7 days of the week, your physical activity level is 9
Multiply your BMR by your physical activity level.
For example; A 25 year old male whose height is 170 cm and whose weight is 78Kg will have a BMR of 1,723 calories/day.
If this male is moderately active, the number of calories required by him on a daily basis to maintain his weight will be
1,723 * 1.55 = 2,671 calories.
Why you should know your Physical Activity level and Calorie expenditure
- Knowledge of your physical activity level and calorie expenditure helps you check your diet to help you maintain a healthy weight.
- People who live sedentary lifestyles are prone to varying types of diseases such as hypertension.
- Watching your weight enables you not to become underweight, overweight, or obese, helping you maintain a healthy lifestyle.
- If your calorie intake exceeds your calorie expenditure, improve your physical activity level by doing more exercises.
- If your calorie intake falls below your calorie expenditure, reduce your physical activity level by doing less activity and exercises.