Core work

I've been doing core work for several years.
Consistently 2-3 times a week to supplement my running.

Does it improve race performance?
Does it help prevent injuries?

I don't know for sure, but I believe it does both.
It's hard work and I probably would'nt do it if I didn't think it provided some sort of edge.
Todays work-out:

3 sets

40 push-ups
30 milicurls
50 trunk tilts(30 lbs weights in each hand)side to side motion, lowering dumbells to knee level
50 trunk twists (55 lb plate held at waist level, rotated from side to side, standind up-right with feet shoulder width apart