We are becoming more and more sedentary in our life that some are even not taking the time to leave their desks at lunchtime. My answer would be that you have 3 choices: a light jog for 30mins, HIIT session (15-30mins), Super Intense session lasting about 9 mins (4x 60sec sprint plus 3/4mins recovery).

The increased metabolism helps burn more calories at a faster rate. This means in 24 hours after a HIIT workout your body is still burning calories and fat whereas, in steady-pace workouts, you may not.