Lactate Stacking for the 400m By Stewart Marshall

This Blog article was written by Stewart “Stew” Marshall (on Twitter: @Stew_CoachUK) for

Elements of this discussion form part of my personal presentation called “My Rabbit Hole of 400” a work that started many years ago in its thought process and more recently is part of a bigger slide deck, covering the many areas of 400m training theory such as Traditional, Long to Short (isn’t that traditional??? Hmmmm) Short to Long and of course Concurrent TheoryCritical Zone, even covering the recent buzzword “Polarised”. A look at their differences and similarities and why many roads “can” indeed lead to Rome (just some are a little better paved than others).  The main part of this presentation looks at some of the bioenergetics of 400m competition and training and attempts to conceptualise some training theory, based around Lactate Stacking.

What is Lactate Stacking!

Well in all honesty, you already do it! It’s essentially just interval training! Its performing a rep in a controlled manner at a given intensity to systematically increase the byproducts within the body, and after a set amount of recovery; performing another rep and layering another layer of fatiguing byproducts on top of that already created, repeated until the desired effect has been reached. 

So, we already do I it?

Well, the problem with this is very simple, we have gotten lazy over the years as coaches and simply prescribed antiquated training sessions and let the athlete run until they can’t complete it. Now, you could say goal achieved, as you have taken the athlete to the point where they have accrued a large amount of fatigue and acidosis that should stimulate some level of adaptation. Right?

400m Fatigue

The main limiting energetic factor in the 400m will be the Glycolytic system and its contribution to providing the required energy.  And its subsequent cost in what the world calls “Lactic Acid” (I’m not a physiology snob so we will stick with it) but most importantly for this article it’s the increase in hydrogen Ions (H+) that is the issue, which can be monitored by measuring the Blood Lactate levels of athletes and the increase in muscle acidity.

You see this H+ build up and subsequent change in PH level of the body (hence the afore mentioned “Lactic Acid” / Acidosis of the muscles),  is believed to be a main factor in the very performance limiting fatigue experienced at the end of the 400m race.  And what those of us who have done enough training to encounter it, would call Butt lock, Heavy legs and “where’s the nearest bin to throw up”! In fact the build-up of H+ and also phosphate ions begin to inhibit the contractile ability of muscles (reducing the power output ability) via mechanisms that effect the cross bridging of sarcomeres.

Now the level of these “Ions” in the body can both be trained to be lower and to be tolerated, in fact most of the time the same training will do both.

Let’s do a little research

Now as you can see the lactate levels measured (from which we calculate the rise of Ions and subsequent acidosis) at the end of the 400m in this instance are at approximately 12mmol and rising to 16mmol measured via the blood. To clarify, Blood Lactate will rise for the next several minutes after intense exercise as the lactate is diffused from the muscle to the blood which is why the post run sick feeling happens, as you can see in the image, the blood lactate falls and the blood lactate rises at the end of the event.

During the 400m race these levels slowly rise as the body produces the energy and biproducts and tries to keep the engine running,  there is a steady rise from the very start of the race and from as early as the 100m the diffusion from the muscles to the blood starts to exceed capacity (a few factors are involved in this and how we can support this part of the race but that’s another article)  and the subsequent neuromuscular fatigue starts to hit!

So what does this mean?

Now of course in the coaching community there is a growing movement around specificity, rightly so! The more you do something exactly, the better you get at. But you can’t keep doing loads of 400m races.  The closer in specificity to the event the less number of times we can reproduce that effort, i.e. how many 400m races can you complete in a day? How about in an hour? How many 50m can you do (depending on recovery and intensity)? These factors can then shape our training to best get the athlete accustomed to the fatigue requirements! 

So If we can’t just keep running 400m, what can we do to get better? Well for this purpose we are not going to look at the mechanical or neurological elements of the speed requirement. We are looking into the metabolic requirements (speed again is a whole other discussion) and for this article specifically to cover the fatigue tolerance (depending on ability of course).

We want to improve our bodies ability to “tolerate” the fatigue levels we incur during the races closing stages. Now if there is one thing we all as coaches and athletes need to be very aware of, intensity is key! We modulate our energy and biproduct requirements via intensity (we can walk an awful long time as the intensity is low etc) The slower we go from our maximum the less level of debt we accrue and can therefore handle the pace for longer (Speed Reserve) and we can use this within our training intervention to programme our “Tolerance” sessions.  This actually highlights why the “Many Roads lead to Rome” of 400m training and the difference in plans you see with different coaches, and plans from the past and present and why many different ways seem to be successful.

Figure 1: Stewart Marshall – My Rabbit Hole of 400m

How does Intensity affect Lactate?

Taking a very quick look at some more research we can delve a little deeper in how we can manipulate variables to use within our training intervention.  Using Decathletes for research they were able to identify that for some athletes, the Lactate post 100m (100% intensity) was close to that achieved during their 400m (92% average intensity??) and similar to the afore mentioned research on the 400m Lactate levels seen within Blood and Muscle.

Figure 2: Lactate Levels of Decathletes in Competition
Figure 3: Average levels of Lactate from Decathletes in Competition

The higher level of intensity we work, we produce more ‘Lactate’, from the image above we identify that the decathletes, whom we can relatively assume would be classed as “fit” and “well trained” hit high levels of Lactate during their different events at a competition.

Highlighting the Intensity of effort plays a crucial role!

But what about in our normal day to day training?

Figure 4: Different Training Session Lactate Response

For most 400m coaches and athletes, sessions 3, 4 and 5 will look very, very familiar.   As you can see these are very typical standard sessions we have all done at some point and through the utilising of intensity modulation, repetition numbers and crucially recovery, the output has been manipulated to accumulate a level of fatigue and biproduct saturation.  So let’s look at their lactate scores!

Session 3, 8x200m

A very “traditional” session in most coaches rotation, hitting 20mmol of Lactate. Pace would be similar to that seen in the last 150m of the 400m,  This ‘pace’ for some coaches is seen as being the specific reason to include similar sessions.

Session 4, 6x300m

Similar to the 200m session, another consistent member of the coaches arsenal, a very tough session due to the extra distance in each rep, as you can see one athlete did not complete the session as hit 20mmol on the 5th rep compared to the remaining athlete who manged to complete the session around 18mmol. The average pace seen in this session “may” be similar to the last 80m!

Session 5, 3x3x300m

Another big volume session, this time using a more familiar set breakdown to allow some clearance of metabolites which can been seen in the Ammonia and CMJ differences.  But again the session starts to push upon the 20mmol.  It’s worth noting the level at the end of the 2nd set was still 15mmol (remember the figure from above?!). Again, the average pace seen in this session “may” be similar to the last 80m!

As you can see from the above training session images, the Lactate levels achieved are in line and above those encountered in the 400m

Now if we go back to the statement around “Specificity” and drill down into what that really means, we identify that we have managed to accrue an appropriate level of fatigue via biproducts similar to the race environment.  However, now the issue then lay in the actual running pace utilised to get this stimulation, the number of repetitions an distances ran at “end pace” or slower, it I sour role to  understand these sessions position and balancing them out appropriately to ensure correct mechanical/speed stereotyping of the athlete.  And importantly from these sessions, the “ramp” time of bioenergetics is not similar due to the level of intensity and stacking in specific way as shown (typical sessions types).  So although we will get some systemic development of our buffering capacity and muscle endurance from these sessions, there is still a disconnect to the event itself, which may be a reason why these athletes may require a few races before getting their grove and hitting the times that they should be.

But the above distances and reps are what we would normally see in most 400m training programmes, so let’s stand back slightly and take a look from a different angle.  If you follow coaches Dan Pfaff and Haken Andersson either on social media or via any presentation they have both done, you’ll be aware of anecdotal recalls of past athletes who have had large lactate levels from repeat block starts and recently coach Andersson has posted on social media readings of athletes with high levels of lactate from utilising similar short distance repeated efforts. Let’s take a look at the table again, and view sessions 1 and 2. Not very “typical” 400m training sessions, but what do the readings suggest?

Session 1, 3x60m, 3x80m, 3x100m

A session that mat be seen within most short sprinters programmes as a “Speed Endurance” day, with large outputs of power and the accrued levels of fatigue, we can see why this might be very effective.  Hitting levels of 15mmol we start to see very similar and “specific” levels of Lactate.

Session 2, 6x100m

Perhaps viewed as a less likely session, but again one with great levels of power and mechanical output and exposure to upright running. Again hitting levels of 15mmol.

Now a large part of this response will be down to large levels Intensity, power output and speed attained within each rep (which would be faster than 400m race pace btw! An important factor here) but there is a build-up of lactate and Byproducts as each rep is completed and the next commenced with incomplete recovery (Lactate Stacking).  We can also see this within other research, look at the table below shows some research utilising repeat 40m sprints (Anecdotally commented publicly by Coach Dan Pfaff also), utilising a 4min recovery period and running until they hit a threshold of RPE or decrement of time (in this case the target was 3%)(usually termed auto-regulation) and again we can see very comparable levels of lactate in the system as per the 400m.

It’s important to consider the session and its variables not just within the session itself but where it fits in the wider programming and also how you can interplay these elements to get the best outcome.  Just for reference within my own programming I like to cover my bases (pun intended! If you know… you know!) And will utilise multiple methods to gain adaptation.  But mostly I will utilise a process of Phosphate Depletion and Lactate Stacking similar to the work that legendary coach Mike Hurst has used for many, many years, manipulating and mixing up recovery and distances to simulate the environment encountered during the 400m to be as specific as I can.

So there we have it, a look at utilising Lactate Stacking to create a training adaptation for the 400m, it’s up to you as coaches to consider its implications in your programming and where it fits and when best you feel it can aid the athlete in front of you! Mixing up intensities and distances can be a really productive method of hitting the elements you want and need to ensure optimal adaptation of not only the metabolic response but also importantly the mechanical.


Beaulieu et al (1995) Blood Lactate levels of Decathletes during Competition. Br.J. Spt. Med. Vol 29, No29, No2 pp 88-84.

Gorostiaga, EM, Asia´ in, X, Izquierdo, M, Postigo, A, Aguado, R, Alonso, JM, and Ibanez, J. Vertical jump performance and blood ammonia and lactate levels during typical training sessions in elite 400-m runners. J Strength Cond Res 24(4): 1138–1149, 2010

Hirvonen, J. Nummela, A. Rusko, H. Rehunen, S. Harkkonen, M. (1992). Fatigue and changes of the ATP, Creatine Phosphate and Lactate during the 400m Sprint. Can. J. Spt. Sci. 17:2 141-144

Jimenez-Reyes et al (2016) Mechanical, Metabolic and Perceptual Response during sprint Training Article in International Journal of Sports Medicine

About the Author

Stewart “Stew” Marshall (@Stew_CoachUK) is a Speed Coach based in the UK specialising in the Long Sprints. He works with athletes at the International level, through to Masters. As well, he is an accomplished Masters Athlete being the 2018 M35 400m World Champion.