skip the 400s and do the shorter stuff. ray and benson's run with the best includes a section on the year-round speed development. but, as mentioned in other posts above, you can keep your speed by doing striders 8-10 x 100m or accelerations (during which you start out at easy pace and accelerate up to 400m pace over the length of 100m). it is important to take a full recovery also. this type of workout will do a great deal more for stride frequency as well as running form/economy. the 400s are dangerous and should be done later in the fall, if at all, once you start doing them you will begin to approach your peak sooner than you want. if stanford is doing 300s and 400s during the summer they may be at VO2max effort. if they are faster, that just seems weird to me, but i am not the coach and they seem to be doing fine. anyway, in most cases the 400s are better done later in the season. if your coach set up a program for you, stick to it no matter what the people on this board say. questioning your coach could lead to you being unhappy and turning pro before you are ready (haha).