Hello there. The simple answer is the harder you work, the more calories you burn. So if you were to do intervals in that 5k then you would burn even more. If you do it on a treadmill, it may tell you how many mets your work is equivalent to. This, simply put is a scale of effort.

Hope that helps.

Hello.. by intervals i mean sustained levels of higher intensity. These are normally timed or of a set distance. Therefore you can jog for 1 minute and run at a faster pace for a minute until you have completed the full 5k. Or choose a number between 2 and 10. On this instance i will choose... 5! So i am going to jog 5 lamp posts, push the pace for the next 5, then jog the next, and so on.

To answer number 2, its a case of exertion. If on a scale of 1-10, a brisk walk is only 3 or 4, and your jog is 5 or 6 then have your jog.

The rate of perceived exertion is a simple scale used by trainers instead of a heart rate monitor.

Mix it up and only do higher intensity work 2 or 3 times a week. For example do intervals on a Tuesday and maybe some hill reps on a Thursday or Friday and make your other day steady running. If you want to lose fat, do some strength work in a circuits class or some light weights down the gym!

Hello you would burn more with with a slow jog than a brisk walk because you are using more energy. Hope this is helpful.
Skeats