*X Run ‘correctly’, with the ‘correct technique’. This will be difficult to change by the weekend. However try leaning forward a little (from your ankles) whilst keeping your body relatively straight. Breathe through your mouth. Running on your toes (fore foot strike) or ‘flat-footed’ (midfoot strike) is argued to be faster by many, but really you need to have trained for this or you might get injured. Then again 5k is not long to last for.
All the suggestions are starred:
*** 3 stars. IMHO it will work
** 2 stars. It might work
* 1 star. Can’t hurt
X 1 cross. It CAN hurt if done wrong.
All 50 tips are shown here as a series of posts : http://the5krunner.com/tag/how-to-get-a-5k-pb/ or on twitter using #howtogeta5kpb. They are all SHORT-TERM tips that will work in the next week or so with varying degrees of success.