See the text (Lesson A-12) for the definition of a calorie and the core idea of the need to balance dietary intake (calorie consumption) with exercise (calorie expenditure) in order to maintain, gain, or lose weight. The following site provides a table for the number of calories consumed per hour of different activities. Unfortunately, if you are struggling with losing excessive weight, increasing activity alone is unlikely to shed pounds, other benefits notwithstanding. Evolution has designed metabolism and weight gain as a protection against famine. If there is no famine in the picture, exercise (calorie burning) will be balanced by greater appetite, hence increased calorie consumption. The only thing that will shed pounds is a diet that in one way or another reduces calorie consumption, i.e., imitates a famine.