One of the best and most effective ways to shake up your current workout program and burn mega calories is to try interval training, according to fitness equipment supplier Life Fitness.

Interval training is a type of cardiovascular workout, which can "supercharge your endurance, strengthen your heart and lungs, and help burn calories at a faster rate".

Life Fitness recommends the following: Spend at least the first three minutes on the treadmill at an easy warm-up pace, slowly working your way to a moderate pace. On a scale of one to 10, (one being a standstill, 10 being an all-out sprint) moderate pace means you are working at about a six.

Next, add either speed or incline and work very hard for one minute – this will be a nine on the previous scale. Then take the treadmill back down to a moderate pace and spend three minutes recovering. Repeat six times and spend five minutes cooling down, working at about a two.