.............................. wrote:
you should do continuous running, but fartlek and tempo stuff might be better for you than just 4 days of "going out for a run"
to the OP, there is some great and solid advice already, and I'm going to add a few pieces. having coached 200m/400m athletes who have run XC, and have had excellent success at the higher levels (All-American status on the track), the above point is something that I incorporated.
I recommend forming a mid-distance xc group--sort of a subset of the normal XC team, that trains together 1-2 times per week, where the primary goal is to foster group identity/ sprint cohesiveness, with the secondary goal being development of sprint dynamics through xc training. workout examples would be, while the standard XC team is doing a workout such as mile repeats, the mid-d group would be doing 6-8x 3 minutes at a quick tempo, with 90" recovery, usually ending with 1-2 longer sprints at a high intensity (80-150m at 80% of full effort).
A basic tenet of sprinting at the high school/ early development level is knee lift, and XC is a great way to develop strength in your hips and thighs to increase your knee drive. When you are doing your hill repeats, or other longer hill sessions (could even be a long run over a hilly terrain, or a hilly XC race) remember while you are running that it will improve your strength and range of motion, which will improve your ability to explode out of the blocks. When you're rounding the final turn in the 400, and your body starts to get tired, you will be able to fight it off, due to increased strength gained from XC.
Be careful in the weight room during the fall, as you will still be competing, but transition it to a winter session, so that your physical strength gains will be maximized when you begin racing in the spring.