Slow down

This may sound counter-intuitive, but decreasing the speed at which you work out can actually boost up the efficiency of your routine. The trick is to up the intensity while you slow down.

For example, adding an incline to your regular treadmill run ups the intensity from moderate to high, helping you build endurance and burn more calories while running at the same or even slower speed. Or recruit additional muscles by slowing down each resistance repetition, lifting up on a count of four and lowering down on a count of six. This way your muscles will fatigue with fewer reps, but the time under tension is increased.

Get outside

If you are looking for a fun activity that burns the most fat and has the best functional benefits, take your workouts outside. Climbing outdoor stairs and cycling off trail makes your body rely on its natural powers as opposed to elliptical machines and stationary bikes that constantly support your weight. Besides integrating your balance, you'll be training many stabilising muscles that are otherwise not used on a steady machine.