METCON is a category of exercise routines that are designed to burn a ton of stored energy in a short amount of time. The main principle behind it is moving from exercise to exercise with minimal rest, while maintaining form. METCON protocols such as: HIIT, Tabata and circuits, have been proven to be one of the most effective methods for increasing endurance, burning calories and improving overall fitness and strength. Very light dumbbells and your body weight is all that is required.