I've been looking into different research on exercise intensity and fitness. The study looks at which factors determine total energy expenditure among Japanese men. The study cites high-intensity exercise and lean body mass as the two most signifcant factors, making up 51% of total energy expenditure.
The second study shows that 40 minutes of high-intensity aerobics increases the resting metabolic rate(RMR), unlike resistance training which did not raise RMR in this study.
A third study shows that high-intensity exercise raises metabolism over time, and gives a solid recommendation: "It is suggested that in the prescription of exercise to patients in weight reduction programmes, bouts of vigorous exercise interspersed by one or more days of relative inactivity, will be more effective than a constant level of exercise."
