Runners - what is the name (if any) and science behind this technique?

Question

I've heard runners and trainers claim one of the best ways to burn fat while running and increase speed for longer distances is to sprint for a short distance (say, 25 yards) then walk for a short distance and sprint again, and continue.

Is it true you can burn more fat and increase speed doing this than say, running a brisk, longer distance run and why? Is there a name for this technique so I can read more about it on the internet?

Thanks you for your answers!

Answer 1

Its called HIIT (High Intensity Interval Training)  It will make you faster because you are working near you anaerobic threshold and will create more fast twitch muscle fibers

Answer 2

Many people call it speed interval training. Yes it does help you become faster. But you also need to incorporate other running workouts into runs.

ex. tempo runs, fartleks, hills, cross training, etc.

This website will help you; www.runnersworld.com

Answer 3

I 've heard it called  FAHRTLICH training  its german and needs an umlaut (. .) above the A.