In January I will be working with 12 and 13 year old boys and girls preparing them for track season. This gives me 20 weeks of training to prepare them for their big meet of the year. I will have two days a week to work with them, Mondays and Wednesdays, each session being an hour and a half. My thinking to this point is to have the first part of each work out be the structured portion and the second half be focused around games that develop motor skills, general conditioning and are there mainly for fun and to keep the kids interest. Now my question is should the structured part of the training consist of day one being more speed and power oriented training and day two being a general fitness day with tempo and circuit training. Or would it make more sense to have both the speed/power and general strength/endurance occurring on both days. Also, I was wondering if someone could give me a general guideline of high intensity to general fitness ratio volume wise. I know Charlie talked about having enough high intensity work at this age for intermediate fibres to be converted to fast twitch, but also mentioned that at this stage the largest gains are made through general fitness. I want to try to get the balance between the two right. Thanks in advance 
!
If there is to be 2x/week training, would it be possible to go Mon and Thurs? If not, is there another activity in the equation. It’s hard to answer you question about intensity, as most training elements will be fairly intense for beginners with no background. You can combine some short speed with some general fitness on both days, though you might vary the emphasis between the sessions.
I should be able to move to thurs. Instead do you think it would wise to have three sessions a week, mon, wed, fri? I thought this might be too much for the kids at this stage without any training back ground.
Twice a week on Mon and Thurs would be best in my opinion.
thanks for the input! 
In the past i have gotten my kids to do abs and core work at home a minimum of once a week besides comming to practice. I agree that 2x a week is plenty. My kids have the option of comming 3 times, where they will do really really easy tempo, and I tell them to do a tempo workout on their own (which I do not expect them to do, but I still tell them I expect it).
With speed work it really depends where each individual kid is at. Speed work for one may be up to 30m and they begin to fall apart due to either lack of strength or speed endurance. At their level it is a juggling act for the coach. It is essential to know why the kid isn’t going fast over 40m, or 50m, and then taylor the workouts to suit the kids needs. If it is strength, then that takes alot of time to develop (years and years); if it is speed endurance, not so much time, and still the top end speed will be reached sooner for a young developing athlete due to the usual lack of strength at that age anyways. General endurance is usually fairly good in active kids, and is not a big worry.