[seasoup]

The article states that people compensate for increased bouts of exercise by either consuming more calories or decreased activity later in the day. It goes on to cite a number of studies showing this effect.

Basically, if someone runs a few miles, they will reward themselves with a treat that negates or even overcompensates for the calories expended. Failing that, they will do less physical things later in the day... sit and watch TV instead of working in the garden for example.

Sure, some people have the willpower to go for a run and not eat more to compensate, but the majority of people do not. Any those that do might not even notice that they decrease later exertions to compensate.