not a pro runner, but with stuff like exercise, etc i say go to the god of the source....ie, for running = the kenyans. they do a lot of interval work (like has been beaten on above). however, the one thing that sets them apart is their stride length. obviously, the longer your stride, the greater distance you travel in a set time. unfortunately, a)this takes more energy and most importantly b)you have to run at your normal stride, otherwise you create a "braking" effect that ultimately slows you down. so the solution (according to the kenyans who have natural strides that look like they're sprinting) hill work is the key. you find a steep hill (50 to 100yds) and alternate surging up the hill (sprint as fast as possible) with bounding (getting as much "air time" as possible). start with 3 and 3 and then add one every week (no more than once a week). it also has the desired effect of increasing your vo2 max (like interval training). but as always, what works for one may be a detriment to another.
as for pu, try doing your pu after you've benched. another thing is to use bands on some of your bench work to increase your speed. this coming from powerlifting, but speed is every bit as important for power (which is what "strength" really is) as is force. (physics P=F/t). if you increase your speed, you'll find that pu become more effortless, hence you can do them so easily that endurance doesnt really come into play. ok, i'll shut up now, just my $.02 (well maybe $.04).