This is a question what popped up recently, so I attempt to answer it with slight reservation.
Coaches work with athletes on a very unique and individualised basis. This work is founded by the needs of the athletes to develop certain fitness treats and by experience from the past. So copying the last 6 x 400 @ 3k pace workout of any olympic runner, 6 days out on Monday before a race, most probably will do no good for you. This is the better option, but more likely ruin your race chances, what is the worst one.
Periodization has roots, but it greatly varies, athlete to athlete. Look at the training log of John Albon, Obstacle Course World Champ, the months leading up to winning the Trail Running World Champs in Portugal. That training would have defitnessed me and would have done nothing at all, just maybe resulting in excess fatigue of the anaerobic and high aerobic systems. He is a fast twitch type athlete, who needs controlled regular strength and intensity based sessions for perfect and constant stimulation. Probably regular 35km long runs would have also destroyed him. He knows this and trained accordingly with short bursts up the mountains, some cycling and mountain biking and what is not recorded on strava, but most probably skill and strength training, to strategically dominate the 44km technical trail race in Portugal. Fascinating isn’t it ?
Translating this, would be running 100s and 200s with gym sessions and mountain biking for 10k success. No don’t copy it !
This is a good intermediate distance, getting away from pure speed, but not entering the realms of high end endurance like the 800 and above. A 400m specialist is the inbetween runner as an example. Not as heavy, muscular and explosive as the 100m sprinters, but at current race state, not gonna be a successful, lean and mean machine for 800 and above either.
For this reason, we can really play with this distance for the athlete competing in the 10km.
Choosing the correct number of repeats, the pace and the recovery intervals are the 3 factors correlating. You must know, what you want to achieve with the session.
The problem comes from club sessions who vary the 400s on an extreme micro level, what changes nothing.
12 or 2 x 8 times with the speed you can do and recoveries of 10 seconds around your completed repeats. For instance you start out with 12 x 400 @ 1:20 / R1:20. As the season progresses, you might arrive at 2 x 8 x 400 @ 1:17 / R1:10. The workout is aiming the same exact goal, just is more advanced as your fitness is higher. This is due to the lack of understanding of the coach. The lack of track time available. Also, about the close monitoring and about motivating the athlete with better and better times. Kind of !
By actually doing a test and regular testing of an athlete, a coach should understand the needs of that athlete. Endurance, fundamentals, speed, acceleration and so on. This could add tons of variables. Let’s look at these.
6 x 400 @ MAX / R-Full
For a 35min (3:30/km) 10k runner – 6 x 400 @ 1:08 (2:55/km) / R3:30
Running little, for total speed, with full recoveries. Benefits ? Finishing kick, making fast high rep 200s feel easier and later on effecting the high rep 400s. Strengthening the athlete’s body and posterior chain, effecting the anaerobic system and the fast twitch fibres.
The thing here, that the runner should be very strong and experienced, despite the slow 10k time. This is a workout what is a result of built up 6 x 7 second hill sprints, through out a long period of time.
25 x 400 @ 10k speed or slightly faster with little recoveries
For a 35min (3:30/km) 10k runner – 25 x 400 @ 1:24 /R35-45s
This is a long workout for athletes not grasping the 10k pace yet. Who cannot determin the feel for that exact pace.
The advantage of this workout is the little injury risk and the high possible progression rate. Of course we talk about months of working on it. For instance an athlete can start with 15 x 400 @ 10K pace + 10sec /R1:00 and each subsequent workout will be 1 rep more, 1 sec faster with 1 sec less recoveries. Doing this workout once every 2nd week will result a 20week progression towards the 25 x 400 at correct intenisities with recoveries.
Some athletes cannot yet cope with the short recoveries. They can alternate under and over speed workouts to achieve the goal.
Week one could be 10 x 400 @ 10k pace /R25sec recoveries.
Week 2: 30 x 400 @ 10k pace + 5sec /R90sec. Progressing towards the desired 25 x 400.
This workout is a great test as well at about 10 weeks out from the race itself. If you cannot perform this very easy task 10 weeks out from your race, you are in the wrong group, have a wrong objective or need to train / recover differently.
Alternating 200s and 400s
This can be done on many different ways too, depending on the need of the athlete.
10 x (400 @ 10k pace /R25sec + 200 @ 5k pace /R1:20) (Pacing + accelerating)
10 x 400 @ 10k pace -15sec /R-equal + 5 x 200 @ 10k pace – 20sec /R-of 400s
10 x (400 /R35s + 400 /R35s @ 10k pace + 200 @ 10k pace – 20sec /R1:40)
Depending on so many things, athletes can play with speed, increasing speed, ladder sessions, recoveries. When we try doing something out of ordinary, we should have a clear objective outside of creating a simple metabolic confusion and triggering adaptation. It is great to have fitness, but what type, when and why, this is the question !
Tempo + 400s
I really like this session as it shows immediately the weaknesses of any athlete. This can be done on many different manners, depending how advanced the athlete are.
8k @ marathon pace R/1K jog + 5 x 400 @ 10k pace /R1:00
3 x 1600 @ Half-M pace /R1:00 + 6 x 400 @ 10k pace /R1:00
3k @ 10k pace /R3:30 + 10 x 400 @ 10k pace /R1:20
These were the conservative ones.
When you start of course, the very first sessions are something like 4 x 600 @ half marathon pace + 4 x 200 @ faster than 10k pace. We talk about year long progressions before someone can arrive to those monstrous looking kenyan workouts.
What I am explaining here, that there is more to 400 s than the regular 12 x 400 with equal recoveries. They say it is 12 as the first two is always off and either ways, that is what you would need to get warmed up and get tuned in.
Actually, there are millions of ways, literally, to run 400s. Each second of change, each quantity of rep, will deliver another aspect of fitness.
I did not even get into pacing stetegies, like running fast first and last bends, while staying constant in the straights or starting or finishing with a fast 200.
How to know, what to do ? After your quality base period, or if it was really long, maybe in the middle, go and run a 5k or 10k race. Wear a GPS watch and HR monitor. See how you felt, see how you performed, look at your splits, see at what time frame away you are from your goal and so.
If I ran a 35min 10k today, I know that with some discipline, strategic mass loss, sleep, run strength and run form increases, I can get down to 34:00 in about 3months. If my goal was 32:30, that would be about 2 to 2,5 years, with multiple progression waves. I set my 400s accordingly and inject them into my training routine smartly.
What also most people should understand, just because you don’t perform any particular type of workout, even for 2 months or more, you won’t lose that ability. You do some hill sprints, go after mile repeats, tempo and uphill tempo runs, 4min VO2 intervals, long runs with spiced accelerations and so. If your volume was sufficiently smart, that includes general quantity and type of volume, you will not lose the ability to perform 400s on the track, despite that all summer you ran only on roads and trails.
What I am explaining here is that your 400 track repeat progression might come down to 2 single 400 session a month and your improvements will be seen only on a 6 to 24months basis and not one session to the other !
I give some final examples here, what we already touched a little bit up there:
Your 5km time trial died off in the last 1000meters:
You might add a 15 x 400 down ladder, starting out with a relatively easy pace let’s say 10seconds slower than 10k pace. Reaching 10k pace at the 8th repeat and getting faster than that by each rep. Recoveries can be also played with, like an uphill ladder, starting out with 30seconds and adding 2 to 4 sec each time.
You could not hold on to your 10k pace after 5k:
In this case one cause can be lack of specific endurance or lack of strength, depending on which faltered, your CV system or your muscles, both or your head maybe. 400s can help you, but of course 800 to 3K repeats and long runs to be looked at too. The big picture is what should be your whole vision. This article is about the 400, but look at the big picture !
This is where you should be doing more 400s than 12, do a long warming up or a short tempo run before your 400s.
12k aerobic run, followed by 6 x 400 @ 10k pace + 6 x 400 @ 10k pace – 5s /R1min
3km tempo + 6 x 400 @ 10k pace – 5/10s /R1min
Bad finishing kick:
Depends on the length of your kick. If you failed badly in the last couple of hundred meters, a mixture of very hard anaerobic 400s 200s with full recovery will bring your end-range up ! 4 x 400 + 200 @1600m pace /R-Full 3 to 4min
If you failed in the last 800 to 1200meters : in this case the classic 10 x 400 repeats @ 10/20sec faster than 10k with /R1:20 will do the trick most probably. Can cut it shorter if added a good 5k threshold run before.
There is always a what if. There are always more questions, there is always other things to test and understand. It always depends on the athlete and the person ! Some coaches would say that 100m repeats should not be part of any distance training, especially 10k and over ! Well, if the athlete lacks form and the ability to concentrate on certain positions like not crossing over with hands, not flailing the head, not slamming the feet to the ground, yes 100m sprints and accelerations and strides can be an epic way to imprint good habits, but also to develop power, ankle stability and achilles resistance. Same true to all fractionated distance options !