I coach middle school and high school distance runners. This may be long, but here is some advice for ya....
Sure she can drop 50 seconds in one week, but don't be suprised if this never happens again. It's the Law of Diminishing Returns. At first, when she begins to develop her aerobic capacity, there is usually a pretty quick drop. As time goes by, it will be harder and harder to drop those times.
Try to focus on developing her aerobic capacity first. Distance runners do not get fast by doing speedwork all the time. They need to develop their base first. So I would emphasize just doing easy long runs for the first 2-6 weeks, depending on how long the season is. Then you can begin doing some interval stuff. At this age (7th grade), unless she is super competitive, it might be a good idea to keep the intensity at 60-75% in workouts. Just let her have fun with running, and don't let her get burnt out at a young age. Pushing her too hard at a young age may just do that.
The other guys suggestion of the repeat 400s at her race pace is a good idea, especially early in the season. This allows her to get a "feel" for her pace. The main focus should be on economy, good form, and not killing herself in these workouts. Some mixes of 200s and 400s at this pace is a good workout. Just because these are "short" intervals doesn't mean they have to be "fast" intervals. Also allow for a near complete recovery with these, up to four times the interval length. If she takes 1 minute to do an interval here, give her up to 4 minutes to recover. Keep these types of workouts at 5% of weekly mileage. In other words if she runs 20 miles a week, 5% of 20 miles is 1 mile, 1 mile is 1600 meters of work, or four 400s, or eight 200s.
She will also need to do some longer intervals like repeat 800s (maybe 4 of them). Early on, keep the recovery and the intensity low. Recovery should only be about 1 minute. This will be a very tough workout, don't start out too fast. This type of workout is designed to increase the runners tolerace to lactic acid, known as their lactate threshold. Try to keep this at about 8% of her weekly mileage.
Another workout I do that kids respond to well is fartlek (speedplay) workouts. This is all based on time and not distance. Try running 2 minutes hard, 1 minute easy, 1 minute hard, 30 seconds easy, 30 seconds hard, 30 seconds easy. Then repeat this as many times, but probably no more than twice for your daughter. Again this should be about 8% of her weekly mileage.
These three types of workouts are good for early season after the base work. After a few weeks of this stuff, increase the intensity a little bit on the 800 workout, but add a little more recovery, up to the length of the interval. So if the interval takes 3 minutes, give her up to 3 minutes to recover, but make the intensity of the interval a little higher. Also, continue with the shorter interval workout mentioned above. You can be creative with the distances (200,300,400,600) and the number of repeats, but try to keep the mileage at about 5% of her weekly total. You can allow her to do some of these faster now. She has done some work and her body should be able to handle some speed without getting injured.
The last few weeks of training should go back to the first types of workouts. Keep the short intervals from before and the speed. Return to the low recovery, moderate intensity type of workouts. You don't want to kill her legs the last few weeks of competition. This is when she should be looking to run fastest, or "peak." You can slightly back off mileage, but I like to try and keep it somewhat consistent. Maybe only a few miles less per week for her.
Try to get on a routine of working out on the same days. What day are her races? If she races on Thursdays, then try to get a workout in on Tuesdays, and maybe something light, not too intense, on Fridays. Fridays can also be used for an easy run if I feel they need it. I do this with my middle school boys. When we don't race on Thursday, we substitute a quality interval day, with an easy day on Friday. So their schedule is something like this, Mon - easy run, Tues - intervals, Wed - easy run, Thur - race or intervals, Fri - light intervals or easy run. The weekends are their own. They can run if they want to.
I think that practicing twice a day is a bit much. Only have them run once a day at this age. If you do want to practice twice, then the other guys suggestion of working on flexibility is good. Good mechanics and coordination is very important.
Most of what I have told you I have learned from years of running. I also learned a lot from Jack Daniels (not the alcohol but the Dr.). Check out his book "Jack Daniels Running Formula." It goes pretty in depth, and you may have to read it a few time to comprehend it, but it is a wealth of knowledge.
And last of all, good luck. Have fun. Allow your daughter to love running and she will stick with it.
email me if you want: cdonlee@sbcglobal.net
[This message has been edited by cdonlee (edited 2/27/2006 10:54a).]