I recently learned that the science has changed and I can recommend the book Burn by Herman Pontzer on this:
The human body can adjust the Basal Metabolic Resting Rate quite a lot in the face of exercise. Spending an extra 500 kcals on exercise can easily only lead to 200 kcals higher total energy expenditure. The body apparently will for instance reduce sex drive and immune functions when under regular exercise. So to achieve weight loss exercise alone is a very hard path unless diet is also modified.
In other words the mechanistic model of "calories in minus exercise calories minus resting calories" doesn't work well or at least it is harder to assess "calories out" than it seems at first hand.
It saddens me that it is not universally understood that the way to get in shape is not to exercise but to stick religiously to a diet of only fatty beef, eggs, and sardines.
The human body can adjust the Basal Metabolic Resting Rate quite a lot in the face of exercise. Spending an extra 500 kcals on exercise can easily only lead to 200 kcals higher total energy expenditure. The body apparently will for instance reduce sex drive and immune functions when under regular exercise. So to achieve weight loss exercise alone is a very hard path unless diet is also modified.
In other words the mechanistic model of "calories in minus exercise calories minus resting calories" doesn't work well or at least it is harder to assess "calories out" than it seems at first hand.