Staying healthy life needs constant expenditure of energy. Over a long run energy expenditure is equal to energy intake. A healthy male with a 60 kg of weight needs 2800 kcal/day of energy. Female 50 kg of weight needs 2200 kcal/day of energy.
Components of daily energy expenditure
About 60% of our energy is used to maintain Basal Metabolic Rate (BMR). Basal metabolic rate is the energy used for our heart beat, respiration, urine formation and other body function that is necessary to stay alive.
About 10% of our energy is used as a thermic effect of feeding. Energy used to digest the food we eat. This part of energy expenditure can be taken as tax payment as after digestion extra energy is released.
About 10-30% energy is used as a thermic effect of activity. This form of energy is used by physical activities like walking, cycling, running and so on. This part of energy expenditure we have to consume more to balance the energy expenditure and maintain normal body weight.
Many of us do different activities to maintain their weight. Walking, running and cycling are the common activities most of us prefer..
Walking 1 km of distance will consume 0.5 kcal/kg of energy. (If we walk 3 km/hour)
Running 1 km of distance will consume 0.9 kcal/kg of energy. (If we run 10 km/ hour)
Cycling 1 km of distance will consume 0.4 kcal/kg of energy. (If we cycle 10 km/hour)
As compare to walking, running costs more energy because there are use of lot of muscles. Cycling costs least amount of energy because speed is gained by mechanical advantage of the bicycle but cycling covers more kilometers in 1 hour. This is just an example if more kilometers are covered in 1 hour depending upon person to person more calories are burned.
To balance in the energy expenditure.
We can take the example of 60 kg man that need 2800 kcal of energy per day.
Energy used as a BMR 60% of 2800 = 1680 kcal
Energy used as a thermic effect of feeding 10% of 2800 = 280 kcal
Energy used as a thermic effect of activity = 2800-1680-280=840 kcal
We have to burn 840 kcal of energy daily for balanced energy intake. If someone is eating more than daily calories then have to consume for kcal than mention above.
In 1 hour if we walk 3 km, 1 km of walk can burn 30 kcal, 1 hour of walk will burn 90 kcal of energy. To burn 840 kcal we have to walk 840/90= 9 hour.
In this case we can compare the calories burn due to just walking then have to walk for 9 hours a day but there are different activities we do in a day like cooking, using cell phone, shopping, washing clothes and so on that will also burn the calories.Those who are having sedentary lifestyle then they have to do more physical activities otherwise it adds extra amount of energy in their body. Moreover those who want to use more energy they can adopt for running, cycling, swimming or other kinds of physical activities.