How you go about accomplishing this with your workouts is very much up to interpretation. You may choose to do basically the same workouts year round and to change how they are executed in order to accomplish the goals of your season. You may choose to do very different workouts for each phase to a such a degree that a sample week from each phase would seem completely unrelated. As long as you have embraced the general idea of progressing workouts to build to a peak set of races and a new plane of fitness you are ready to lay out your schedule.
Step one in setting your schedule has to be time. When is your goal race? How many weeks do you have between now and then. If the answer to that question is much less than twelve and you are not already about as good as you think you can be long term then I would suggest that you pick another goal race. It is certainly possible to get ready to race in 10 weeks, or even less time, but you are not going to make any step forward in your general fitness. Basically you can only run up to your stored potential not change your baseline. So for example Nick Willis was hurt this spring and only started running 10 weeks before worlds. His first workout was only 7 weeks before worlds. The result? He finished 8th. So frankly the results were awesome. The thing to remember is Nick's baseline after all these years is incredibly high, there are no major breakthroughs left to make. He is within spitting distance of the limits of the human body as we understand them today. I have little doubt that if this was 15 years ago and Nick was in college and running just under 4:00 for the mile he and his coach would have approached things differently targeted fall cross country, trained through worlds, got knocked out in the heats at worlds, and made another step towards becoming the sub 3:50 miler and two time Olympic Medalist that he is.
This raises the question is there a block of time that is too long? Arthur Lydiard would say no, he liked to do year long cycles. Personally I find that though I can make a cycle longer than 6 months work I don't seem to improve as much as if I break that period of time into two cycles. So if you are looking at something in the 8 to 12 month range I would find another target race about half way between now and your big goal race to target as an interim goal. In the long run I think you will find you will run better in the big goal race doing it that way.
Once you know how much time you have you can create your cycles. If your goal race is a marathon then you are going to taper for 1 to 3 weeks before the race and the rest of your season you will be training pretty hard. If your goal race is shorter you may want to create a racing season of 4 to 8 weeks around it where your mileage is low, 50 to 60% of your normal volume, with lower volume, high intensity workouts and a lot of racing, at least one per week. I would put the main goal race 2 to 4 weeks into this race phase, the first couple of weeks of lighter volume will serve as the taper and realizing that after 4 to 8 weeks of training at this lower volume your fitness will start to erode.
For your specific phase you want to plan 5 to 7 weeks. You can squeak by with 4 weeks particularly if you are doing a shorter distance racing season like described above. You can stretch this to 8 weeks, particularly if you are focused on a marathon or half marathon and have a half marathon or two slipped into the specific phase as tune up races. Keep in mind that there are limited returns on the specific phase. Meaning that if you go too long you will not get faster. This is the training that shapes your fitness not the phase that builds it. You polish the diamond but you aren't making it bigger or harder.
Some people do a very clear middle phase, a pre-competition or special phase. For me it is always the transition period from the end of the base and the beginning of the specific phase. So in my case it isn't well defined. I may be doing a workout that is really a special phase workout for one system while my other workout the same week is really still firmly in the base phase. Either way this phase should really be three or four weeks. Five at the absolute most. You are starting to do some very hard, and in the case of the 10k down, very anaerobic workouts here. On top of that your volume is still very high. If you push this phase too long you are just going to end up sick or hurt.
The rest of your time is the base phase. For me this is a period that naturally progresses into the special phase and I adjust the progression of my workouts based on how much time I have. You have a lot of flexibility in the length of this cycle. The work you are doing may be hard but it isn't as tough on your system as some of the other phases so you can,in a jam, easily train like this for 3 months or even more. Ideally I suggest 6 to 8 weeks but longer is ok.
You can get away with less but this is the phase where the work is done for big improvements so you are selling yourself short if you are cutting this cycle short. However in a situation like high school or college where you are running three seasons this can be tough. My advice in those situations is to follow a program that has less variation from cycle to cycle so that you can always be in acceptable racing shape but utilize subtle adjustments so that you are actually targeting long term improvement. Also during the early part of the indoor and outdoor seasons try to hit a couple of very good base phase workouts. For example a strong fundamental tempo or two or a really good hill circuit workout. These are good because you need them but also if you have been doing a lot of race specific work you are really starting to get limited returns by the end of the season and doing these sort of workouts for a couple weeks gives your body a chance to target other systems and your mind a chance to focus on different tasks. This will not only be better for your physical development but also for your mental motivation and sanity. Then of course you can get in an extended base phase during the summer.
To set up your general outline go through this process:
1. When is my goal race? count back your taper from that day.
2. Allow 4 to 6 weeks for specific training.
3. Allow 3 to 4 weeks for special training.
4. How much time does that leave? If it is less than 4 weeks strongly consider changing your goal race. This time is your base phase.
A word on racing through the phases. It is ok to race in all of these phases but races that are run during the non- specific phase should not be tapered for, it is always ok to reduce training after to recover if needed. Also it is important to understand that improvements in the early and even middle phase may not translate directly to results in racing. This is more and more likely the case the shorter the race you run. It is key that you focus on the progression of your workouts during this time instead of any race or time trial to measure your fitness gains, as these can be misleading. For example lets say you ran 10:00 for two miles last spring and you are spending your summer doing base work after a couple weeks recovery back in June. Over the last couple months you have taken your fundamental tempo from 6 miles at 6 minute pace to 12 miles at 6 minute pace. You have also found that in your hill circuit you can now do 5 sets instead of the 3 you started with and your able to accomplish each set 5 to 10 seconds faster. You have made a huge jump in fitness! But if you go and run a two mile time trial with your teammates to kick off cross country season. You will likely run in the 10:20 range. This can seem like a failure. I mean you were so much faster in the spring. The key is that you have not been training to improve your race specifically. You have created in your body a fitness that will enable you to do the workouts needed to run a much faster 2 mile but you're not there right now. That is totally ok because your state championship is still almost three months away and you will be ready to split sub 10 on your way to 5k by the time it rolls around. You need to focus on the improvements in your workouts as a measure of your increased fitness.
That said don't panic if you do run 9:50 in our hypothetical time trial. As long as your base workouts have shown improvement it just means that your base fitness was so poor that you have been able to move past your sharpened up race fitness by improving it. Your in for some great improvements. However if you did improve greatly in the time trial but you hadn't seen improvement in your base workouts you may want to re-evaluate your training as you may be doing too much specific work and not enough general fitness work.
Next up you need to progress our workouts through the phases. All of your workouts should have a logical progression and a specific end goal. They may get longer, they may get faster, the recovery may get shorter, but each should have an end goal and a clear step by step progression there. That goal should be directly related to your race goal. If you are having trouble figuring this part out it can be helpful to think of it this way.
What are the workouts needed to run X time for my goal race.?
Those are your final goal workouts.
Now what type of workouts would set someone up to do those workouts?
Those are your special and early specific workouts.
What type of workouts need to done to build the general fitness to do those workouts?
Those are your end of base phase workouts
What am I capable of doing right now for the type of workouts I want to run at the end of my base phase?
Those are your starting workouts
Let's look at how a couple of workouts might progress through the seasons. First let's stick with our 10:00 two miler heading into cross country. Looking at his specific pace work it is reasonable for this athlete to have a goal of 15:30 for a fast 5k, or a 5k goal pace of 5:00 mile pace. In the base phase I would have this athlete start with 10 to 20 200 meter reps at goal pace with 200 meters jogging or 1 minute standing recovery. The idea would be run the pace as even and as relaxed as possible. You don't want this to be a hard session. The second session would be 20 to 25 x 200 with the same rest, the same pace, and the same goal. We have simply extended the volume of the session. The third session would be 12x400 meters at goal pace with 2mins recovery, once again you have the same goal of relaxation. We have kept the global volume the same but increased the duration of each rep, moving us one step closer to our end goal of holding this pace for 5k with no breaks.
Keep in mind these sessions would be among the easiest of the base phase, as specific work is the least targeted during this phase. Moving into the special phase I would do the 12x400 again but now with only a 100 meter jog recovery, same pace but now the goal shifts a little. You still want to be as relaxed as possible but if the workout gets hard then you need to run as hard as needed to still hit the pace. At the end of the special phase I would extend this workout to something like 8 to 10x600m at goal pace with 200m rest. As you come into the special phase the frequency and the intensity of the specific workouts should increase. Also your max lass workouts should now involve a lot of specific pace running, and your alternations/threshold work could now involve a lot of specific pace running as well. The specific workout we have been tracking would be repeated a few more times during the specific phase, each time increasing the distance of the rep while not changing the pace or increasing the recovery.
Let's look at another type of workout and how it might be progressed. Mile repeats. Using our same athlete and assuming a mile PR in the 4:30 to 4:40 range I would have him start with a session like 6xmile at one minute slower than mile PB, so 5:30 to 5:40 with a full 3 minutes recovery. The goal of the session in this phase is to build muscular endurance and aerobic fitness. The reps should feel very relaxed and the recovery should seem to long. I would not progress this workout much through the base phase but I would repeat it a few times. Measuring improvement by how much more relaxed the athlete can feel. Moving into the special phase I would keep the number of reps, 6, and the rest, 3 minutes, the same but I would increase the pace. Trying to run 5 to 10 seconds faster, per mile, each time the workout is repeated. I would carry this type of increase into the specific phase. As the pace approaches 5:00 per mile this workout will get very hard and it may be necessary to decrease the volume to 4 or 5 repeats in order for the athlete to complete the session at 5:00 pace but in young or fast improving athletes you will often see them able to run the goal pace for 6 reps by the end of the specific phase. So in this case we have adjusted a workout to change it's focus rather than adjust the intensity of a workout to match the phase. As a side not if I was prepping the athlete for the 10k I would likely not drop the pace all the way to 5k pace instead stopping at 10k pace, say 5:10? for this athlete, but I would reduce the recovery to 1 or 2 mins or a 200 to 400 meter jog.
To sum up. Find your timeline. Plan for a taper or racing season, plan 4 to 6 weeks of specific training, 3 to 4 weeks of special training and the time you have remaining is for base work. Make sure that your workouts address all areas of fitness with particular focus on the four pillars of successful racing, http://nateruns.blogspot.com/2017/08/four-pillars-of-training-for-fast.html. Make sure that your workouts all have a purpose, which often is to build the ability to do the next similar workout, and an end goal which should be to race a specific distance at a specific pace or competitive level.