Swap a 45-minute slow jog for a 25-minute interval session to supercharge your metabolism and your fitness levels. You can burn a great amount of calories and increase your fitness and running ability quickly.

Doing intervals basically means alternating between short periods of hard work and short recovery periods during your session. To introduce intervals into your jog, intersperse faster bursts of running with more moderate recovery periods, which allow you to get your breath back. For example, after you've warmed up, try alternating one minute at a faster pace with 90 seconds at a slower pace to recover, and repeat five times, working up to ten times as you get fitter. Aim to do one interval session a week.