Being a hulk by exercising with no effort (for the lazy)

It is a fact of life that most people do not exercise enough. This, combined with a diet rich in sugary and high-fat fast foods, has led to a flood of overweight and obese people in most western countries, which is becoming increasingly difficult to reverse.
The problem is that for most people it is too easy and convenient not to make any movement.
If you need the daily staple food - even if it's just a carton of milk or a loaf of bread - it's quicker and more convenient to get in the car and drive to the business than to walk.
If you have to go to the third or fourth floor in the office, it is easier (though not always faster) to travel by train than by stairs.
Still, many people are willing to pay hundreds or even thousands of dollars each year to be a member of a gym or a fashionable fitness club to stay in shape.