I had high hopes for this spring, but the COVID19 lockdown ruined most of it. Luckily I have remained motivated to train throughout. A coach at my club, Atlemo, suggested I could give a lactate test a try to see where I am at. I ended up agreeing and thought I would take the opportunity to write another blog post. Time to reflect on the past months of training and cast a hopeful glance into the future.



After the BSK indoor at the end of February, I was a bit disappointed with my result. The goal for spring, however, remained the same: sub-17 5000m. My idea was to stick to 100 km for my regular weeks and try to decide on a race in May or June as the main goal. I did not have any in mind yet, so started out with just some CV and Threshold work as a way to maintain. Two weeks went by easily.

And then the world fell apart. COVID19 hit Belgium and we went into lockdown mid March.

That Friday 13 March, I improvised 200m Repetition work on a flat-ish marked stretch, part boardwalk, and too narrow when people are around. It was the third up week of 100 km, so the 80 km down week that followed was nice to rethink my planning. It was quickly becoming clear that any tune-up races might be out the window. Tracks were closed down too. Threshold seemed like an easy one to keep in the planning as it does not need to be as precise, but I did not want to do that two times a week. As my second workout of the week I planned in 400m R work, figuring I could work on speed a bit. Of course for that one, a track would be much better, but I hoped I could mimic it enough by just going hard. On longer type workouts (like CV or VO2max) I thought to be more likely to settle into a pace that might not be hard enough, without a track to ground me. As always, Sundays remained for long runs.

The thresholds felt pretty good. I run them by heart rate to keep the effort consistent, but the pace surprised me at times. (~18 min 5k) After two weeks, it was becoming more clear that no races would be happening any time soon and I dropped them from training. Instead I switched to two Repetition workouts per week to work on form and speed.

For the 400 metres, I found a straight bike path where I used my watch’s GPS to find two landmarks more or less the right distance from one another. I debated getting a rolling measuring tape to Do It Right™, but eventually accepted that it was not going to get perfectly measured. Heck, it was not even flat. At least I could be consistent with my stretch of running. I would alternate the direction of the stretch on every rep.

The first week (the week of 23 March) I did 10 repetitions, aiming for 76 seconds at the slowest. The next week I changed that to 12. Eventually I split it up into 3×4 to allow for bathroom breaks. Either way, it was all R work for the weeks after that. How this workout felt, depended heavily on the weather. There is no shade on this stretch and the time I usually ran it at placed the sun beaming straight at me. More annoying was the wind. Quite often it felt like it was blowing straight along the path. If that happened to create headwind on the uphill direction (recall it was not flat), then it made for really rough work in the one direction and really easy super speedy work in the other direction. A track was sorely missed.

Mid April I decided to make good use of the extra free time I had gained from not commuting any more. I bumped up the weekly distance from 100 km to 110 km. I think my body handled it well enough and it is now the new normal. My usual split is: 10k recovery, workout totalling 17-18k, 15k GA, 10k-7k recovery double, workout totalling 17-18k, 10k recovery, long run to fill up the distance.

Eventually (i.e., the week of 11 May), I got word that my athletics club would be reopening training. Track’s back, baby! I first passed by on 19 May and did a rough workout that the headcoach there suggested.

  1. Sprint 200 metre. In an e-mail he had described this as “95%”, but as I expressed confusion he said “just go all out”. I do not know if he figured me going all out would mean I would inadvertently keep some reserve anyway for following repeats.
  2. Run 1000 metre. “Faster than regular, but not too much.” Should still be slower than marathon pace, for example. For this one he told me not to look at my watch and just try it by what felt right.
  3. 2 minutes standing rest/walking back to the starting point.
  4. Repeat.

The headcoach had said he would probably do five reps of this to start out with. I messed up the first rep as I did not realise the all out part. Instead, I ran the 200m somewhat controlled (34s) and the 1000m way too fast (3:37). I counted that one as wasted and figured I would do five after this one instead (so six total). The next 200s I managed to run in 31.x seconds nearly every time, though of course it is me manning the lap button too. I had trouble keeping the 1000s easy enough, assuming the paces I have in my head are correct. Eventually though, they started self-correcting: 3:54, 4:01, 4:12, 4:10, 4:16.

I still felt fine after that sixth rep, so decided to give a seventh rep a try. The 200m still went well enough: 31.low. The 1000m stayed similar to the previous ones in time (4:17), but I did not feel smooth any more. Probably should not have done that. I felt this Tuesday workout still on Friday for some track R work and it probably still somewhat affected me on Sunday in the long run. I am yet to test it out again, though I would probably force myself to do fewer reps when I do.

With the track accessible again, I reintroduced CV work, placing it on Tuesdays. I have done that twice so far, splitting it up as 1200, 1000, 1000, 1200, 1000, 1000. Pace goal is 3:30-3:35 per km.

Talks with the head coach mentioned a lactate testing possibility. I decided to give it a try as I had always been curious, but never really knew what to expect. Mails with the tester (coach Tim Moriau) eventually placed it on Saturday 13 June, which happened to be a down week (now aiming for 85 km, no workouts, but some days with strides). I was told to be rested for it, so that worked out fine.


During the cool down after the 3000m indoor race at the end of February, my abs felt wrecked. I assumed some core work might fix this and have started incorporating some strength into my routine. I also reincorporated some hip stuff I used to do more often. I kind of gleaned it together from some sources, so no great past experiences from others to refer to. Instead I am just making a quick note for a future comparison. It took a little to settle on something as well as on how often I wanted to do it, but eventually I settled on the following routine that I aim to do three times a week. For each I try to look up progressions if it gets too easy. This is just the current look of it.

  • Regular plank, 40s
  • Side plank, 40s
  • Back plank (or whatever it may be called), 40s
  • Other side plank, 40s
  • Regular plank, 40s
  • Lie on back, feet flat on the floor, knees pointing in the air. Lift hips to form a straight line from head through back through lower legs to knees. Do that 10 times.
  • Previous but extend one leg into the air. 10 times for each leg.
  • Clamshells: 10 regular, 10 reverse, 10 reverse in air. Each side.
  • Lie flat on floor, raise leg. 10 times with toes pointing down, 10 times with toes straight, 10 times with toes upwards. Each side.
  • Donkey kick, 10 times each side.
  • The one that looks lie a peeing dog, 10 times each side.
  • Leg/hip circle forward (knee bent), 10 times forward each side, 10 times backward each side.
  • Cat-cows. 10 times.
  • L-sit progression. Currently still with feet on floor. 4×40s. Rest is like 2 minutes.

Lactate Test


The test was planned a bit early in the day and I had to bike 21 km to get there (Tim Moriau works on the track in Huizingen). It was thus an early morning for me, followed by biking more and faster (to get there on time) than I am used to. Not the ideal preparation, but I hope it did not affect the test too much. The weather was on the warm side with 20-21C and sun. The track where the test took place had no shade. Is it perfect? No. Does it affect the results a lot? I hope not, I have no reason to think it did.

To start with, I was told to warm up for about 2 km. There is a ~500m gravel path around the track which I used for that. That took 9:09. After that, Tim poked a small hole into my ear lobe and the actual testing could begin. To start off with, you want two base values. From what I understand, that’s two measurements of around 2 millimoles (also called millimolar) per litre (abbreviated to mmol/l).

The next intervals were on the track, 2000m each time. These were the numbers. The first one I am writing down from memory, Tim did not end up using it in his actual analysis.

goal actual pace km/h mmol/l
9:00 8:57 4:29 13.41 1.2
8:00 8:10 4:05 14.69 1.7
7:50 7:47 3:54 15.42 2.2
7:20 7:21 3:41 16.33 3.5
7:00 6:55 3:28 17.35 5.0

It felt quite alright throughout up until the last one. For that one I started looking forward to the end. After all that, I ran a 2-3 km cooldown where I failed to really get the heart rate down. Unsure if the workout and warmth is too blame or just me going too fast with all the real fast guys zooming around.


As mentioned, for the analysis Tim did not use the first interval mentioned above. Using the four others an exponential best fit is created for the mmol/l measurements in function of the speed in km/h. What kind of best fit I am not really sure, it might just be some Excel default. In my case the exponential fit looks pretty close to just a linear fit between subsequent measurements, though he assured me this is not so for everyone.

Using the exponential fitting function, you then find some key mmol/l points and see what speed is expected for those. In Tim’s analysis those points were the following.

what km/h pace
recovery¹ 12.06 4:58
easy¹ 12.93 4:38
1.5 mmol/l 14.35 4:11
2 mmol/l 15.10 3:58
4 mmol/l 16.64 3:36

¹: In his result sheet it was just mentioned as “Herstelduurloop” and “Rustige duurloop”, no actual mmol/l values.

He describes up to 2 mmol/l as still burning fat. Past 4 mmol/l, lactate will heap up exponentially as you run more and more anaerobically, use more carbs.

In terms of racing, he says it is more relevant for 10 km through the marathon. Not necessarily what I am interested in right now, but still nice to know. He says 4 mmol/l is more or less your 10 km race pace. That is actually a little slower than I had hoped. In my mind the lactate threshold would be more in line with racing for an hour when well rested, as per Jack Daniels’ books. The difference in expected times shows. If it is 10 km race pace, like Tim says, then that makes for a 36:00 10 km, which is equivalent to a 17:15-17:20 5 km (my PR from over a year and a half ago) or a just-below-1h 10 miler (my PR from last year). A rather disappointing result of this test as it would indicate I did not really improve at all. (One caveat here is that he did mention it is less indicative of race times under 10k) Conversely, if the 4 mmol/l can be associated with a 1 hour race (about 10 mile for me), then the 5k estimate drops to about 16:49.

For a marathon, running between 2 and 3 mmol/l is typical. So in my case, running sub 4:00/km pace should be quite doable. Estimating 5 km times is not as precise with this, he also just used a calculator for equivalences for this. It placed me at 17:15. Sad face, that is what I had 1.5 years ago.

Use In Training

All based on what Tim told me.

For training, Tim is pretty vocal on not running between 2 and 4 mmol/l. He calls it a dead zone. So no running between 3:36 and 3:58 per km for me.

Running at 1.5 mmol/l improves fat burning. For him that will be a workout like 6×1000 or 3×2000. Not sure about the rest… (TODO: Check with Maarten). Pace would then be 4:00-4:11, preferably the slower side. Do not want to get into the dead zone.

Running above 4 mmol/l will improve your V̇O₂max. So for example 6×1000 at 3:30. Rather a little bit too fast than too slow. (So the reverse of the previous, again to avoid the dead zone)

I asked about the 200m-1000m-2min rest workout (see training above). He explained it as: the 200m builds piruvate, the 1000m attempts to use it before it turns into lactate. He says the 1000m should be 4:15-4:20 for me.

Caveat: it is a snapshot of this particular moment in time, you will improve/get a bit worse throughout a season.


I am a bit disappointed with the results, it puts me slower than I expected. Barely an improvement over last year’s 10 mile race. Thus I will do a 5000m time trial soonish to compare numbers. I reject his reality and substitute my own: sub 17 minutes remains my goal and also what I will start out at in that time trial.

For his marathoners, he likes to do this test perhaps twice a year. At the start of seasons. For the more serious ones, it might be four times a year, where the extra one is added about 4-6 weeks before a goal marathon. It enables to do any last minute tweaking to the planning if deemed necessary. As for me, I do not think I will be doing this test again soon. I am not quite sure it adds much over a race yet (see above) and the 75 euro is a little bit steep if I do not really see the point. Especially while I am aiming for shorter distances, I might as well just do a test race instead.

Beyond that, competition is expected to restart in August. They are still finalising the new calendar though, not all race organisers are still as willing to organise something. I will have to keep an eye on it and pick some races when I can.