yes its true and proven in science.
Metabolic rate
when you do exercise then you are felling that you mouscle are getting bigger and your body shape is diffrent and you are losing the calories.
Since muscle burns about 8 times more calories than fat, having more lean tissue, or muscle, can increase the basal metabolic rate. Another way of increasing your metabolic rate is by doing frequent exercise. As the body is going through the motions of exercise, the metabolic rate increases to supply energy to muscles through catabolism of sugars. pregnancy increases the BMR~ jmata
You have the right idea: proper strength training is important because it increases the amount of muscle you have, and muscle is your metabolic furnace that will burn additional calories 24 hours a day. For example, if you add ten pounds of muscle in the next year, your body might consume/burn an additional 350 to 500 calories daily.
a 150 pound person burns 352 calories per hour walking on crutches, a 180 pound person burns 409. http://www.livestrong.com/article/320780-calories-burned-on-crutches/
It's because she eats more calories than she burns, not enough exercise, a metabolic problem or other medical condition.
The higher your resting metabolic rate is, the more calories your body burns while at rest. So, while you sit or sleep you could be burning calories as if you were exercising.
a 150 pound person sleeping for 8 hours burns 489 calories.
Basal Metabolic Rate is the number of calories/KJ a person's body burns simply existing, i.e. breathing, sleeping etc., without factoring in any walking or exercise. See http://en.wikipedia.org/wiki/Basal_metabolic_rate.
Increasing the amount of muscle you have will raise your metabolic rate. For example, if you add ten pounds of muscle in the next year through proper strength training your body will consume an additional 350 to 500 calories daily. Muscle is your metabolic furnace that burns additional calories 24 hours a day (not just during and immediately after exercise).
Cold. Your body has to work harder to warm you up, therefore you burn more calories
It depends on the idividual. At a minimum, the average person's body burns about 1,000 calories a day just to survive. More activity (ranging from a desk job to active sports) then burns more calories accordingly.