coach d wrote:
Where exactly did you get the information that lunges and core have a positive effect on running performance?
Core is the new static stretching. There is not one shred of scientific evidence that core does anything for running performance. I can cite multiple studies showing that squats or half squats with several sets of 3-6 reps results improvement of RE of about 5%, but this or for heavy squats only and not other exercises. If you are not doing heavy weights, you are wasting your athletes' time. There is another study that can be cited which shows that heavy squats and plyos, on alternate days, has a greater combined effect than either separately.
Do squats and plyos separately and get rid of the other garbage you're doing. Instead, see Steve Mgness' stuff on slideshare:
http://www.slideshare.net/sjm1368/strength-endurance-training
I do think that core work does help running. BUT, I think I'm talking about creating an "overall fitness" that will allow an athlete to increase mileage and to have better running form/economy. Having a healthy athlete will help running performance (because he/she is not hurt).
Once a new an athlete has mastered core work (i.e. body weight exercises), then it should or could be revisited. And, at the same time, the introduction of the squats that you write about could or should be introduced.
Finally, the Magness "stuff" could be introduced.
How about something like this (for high school runners):
Summer Running: core & body weight
Early XC Season: core & body weight & squats
Mid XC Season, squats, core & body weight, & Magness
Late XC Season: squats, Magness, core & body weight
Championship Season: Magness, squats, core & body weight