Question

Why is energy required for all activities? How can energy be generated? Explain 

Answer 1

mechanical energy is required in all activities . it can not be generated

Answer 2

Energy is supplied to all cells including muscle cells by ATP generated from carbohydrates, fats and proteins .The unit of energy in the cells is called ATP (Adenosine Triphosphate) The body have 4 methods to create ATP, they vary by speed and whether they burn oxygen or not.