In my last blog post I described the DIY lactate test I conducted on Monday in my home.
Below I will first go through the high level results and then point out some issues with the test before finishing with some final thoughts and next steps.
Let me first describe Jan Olbrecht’s very simple protocol recommendations to shed light on why I carried out the test the way I did.
Unlike most lactate testers Olbrecht uses a simple 2-step test for most of his analysis. His goal is simply to identify the balance between the two primary energy systems: aerobic and anaerobic. Getting that balance right is the key to effective racing.
More details on Olbrecht in the next post.
Before measuring these numbers I also measured my lactate at rest and my bodyweight which came in at 0.6 mmol/litre and 69.1 kg (dressed). Weight is particularly important as weight gain or weight loss will generally worsen or improve the result.
The resting lactate is the lowest recorded for me which may be caused by the fact I had only a low-carb meal in the morning (almost no carbs in fact) whereas pre-2012 I would have had a big carb breakfast ahead of a test. Less carbs = less active anaerobic metabolism = less lactate.
I decided to do the test barefoot as the treadmill is already very soft and I wanted to maintain the best possible running form. All previous tests were done in traditional footwear (generally racing flats).
The graph below shows the concentration (in mmol) of lactate in my bloodstream at various paces (in kilometres per hour).
The main objective of the test is to identify velocity at a concentration of lactate equal to 4 mmol/l (called ‘V4’). This is not necessarily the threshold. The real threshold can be anywhere from 2 to 6 mmol depending on the individual (Olbrecht 2011).
The weird drop-of at the end suggests an error in my test protocol. I also did a ‘control test’ to test the anaerobic system. This was done by running to failure at 16 kph with 15% gradient on the treadmill at the end of the test.
This yielded 8.06 mmol/l (lower than the concentration at 15 kph). To ensure I caught maximum concentration correctly, I was meant to measure lactate every 2 minutes after the maximum effort as the lactate rise is delayed. Unfortunately, I got a few faulty readings on the equipment (couldn’t draw enough blood) so by the time I got a good reading (5 minutes after) lactate had dropped to 6.44. The real reading could easily have been 10 or above.
For this reason I discard the control as being faulty.
A few other things went wrong in the test:
- My lactate analyzer requires 45 seconds to measure and I had a few issues drawing enough blood. This meant rest period ranged from 1 minute to 3 minutes 30 seconds (too much)
- I ‘forgot’ to measure 13 kph
- Lactate dropped from 3.33 to 2.77 from 12 kph to 14 kph. This makes no sense so must be down to having taken 2 minutes to get a reading for 14 and only 1 minute to get a reading for 12 kph
The truth is this whole test would be discarded by a professional and I will not be using it for longterm comparison but treating it as a ‘test run’.
Connecting the dots
Just as race results can be used to estimate the likely training paces that are optimal, so can a test that identifies the pace at V4.
For recreational runners such easy paces tend to fall at 85-9o% of V4 pace. For an elite it is closer to 70%. This is because V4 pace occurs closer to the maximum oxygen uptake for a well-trained athlete than an untrained runner and therefore is less sustainable.
Since my V4 pace is 14.2 kph I can estimate easy paces as follows:
|Training state||% of V4||‘Easy pace’|
|‘Recreational’ logic||85-90%||12.1-12.8 kph |
|‘Elite’ logic||70-72%||9.9-10.2 kph |
The truth is my ‘easy’ pace falls somewhere in between the two. My V4 is clearly not fast enough to warrant using the ‘elite’ logic as the pace of ‘easy’ is very slow for me. On the other hand paces of 4:58-4:42 min/km, which used to be my easy pace, are probably 10 seconds on the fast side for ‘easy’ right now.
So comparing estimated paces to this test is a bit off which could be because of testing errors.
Comparing to race results
Looking at my race results this year they started at a very low level, my lowest ever, around a predicted VDOT of 48. It has increased to 54 and now to 56 according to Garmin’s new (seemingly precise) estimator in the 620 watch.
If we assume that V4 is close to the threshold (a fair assumption) then my threshold pace is 4:14 min/km currently (at least on a treadmill).
My first 5 km of the year (19:22) is a VDOT of 51.7 which equates to threshold pace of 4:09 min/km. My latest training suggests I am now closer to 18:22 5 k pace and a threshold of 3:56 min/km.
The test suggests that my threshold may actually be a bit weaker than what the 19:22 5 km performance suggested (4:14 instead of 4:09). But 5 seconds is a small difference and we know that 4 mmol/l is not exactly the threshold. I also had to estimate the point of 4 mmol/l from the curve as I did not get an exact measure of 4 mmol/l for the tested paces.
So lots of little imprecisions. The main thing is to observe that the pace is in the ball park of what race performances suggest. So theory matches reality. That’s great for scientists. But is it any use to coaches and athletes?
Short answer is ‘no use in isolation’. Only by conducting multiple tests and watching the curve moving either right or left and up or down can we begin to see how the training we have done has affected our energy systems.
In tomorrow’s third part I will go into some details of the interpretation. For now we just need to keep in mind that there are a total of 13 different reasons that a lactate curve can change direction. Watch a graphic showing this phenomenon here.
If you look at all my results:
For most of the years my curve moved definitely to the right (the two dark blue lines). The last test (the weird brown line) is a huge shift back left as well as upwards. Why this is will be part of tomorrow’s post.
I knew my form had deteriorated so the purpose of this test was not to prove that. Rather the way to use the test is to use it early in training and then in between each major phase of training. Imagine if after completing the general phase of training for a marathon you find the curve has shifted left. If at that stage you begin your specific training you could be worsening the situation further. Instead we need to identify whether we have overstimulated our anaerobic system, understimulated our aerobic system or a combination of these options.
Is there not another way?
Yes. If your aerobic capacity is weakening during the general phase (because you are training too hard or too fast), then your average paces over the course of the week and in the key steady workouts – such as Lydiard ‘Out and Backs’ – will very likely drop. If paces stay steady you may notice that heart rates are going up at the same paces (you’re straining to maintain the same effort). Both indications that the balance between your aerobic and anaerobic system is moving the wrong direction. This would be the low-tech version.
Value for money
The higher level athlete you are and the less margin for error, the more value such a test would have. Is such a test worth the €100 to 150 they cost for a novice athlete?
The answer is: only if you are curious or think the information will be a good comparison some day in the distant future when you are better. In terms of value the price is very fair as you get 1-2 hours with a trained professional and proper laboratory tests will give you other useful measures such as haematocrit count, analysis and guidance. But if you already have this from your own expertise or from a coach you work with then DYI testing may be better. I have gone this direction because I want to change the protocol of my tests and I want to conduct them outdoors on the track rather than in a laboratory.
I purchased The Edge lactate analyzer for just under 200 STERLING which includes 5 lancets and 50 test strips. Each pack of test strips is £37.80 and you easily need 10 for a test, so roughly £1.5 / strip or £15 / test. The analyzer will have paid itself back in 2-3 tests this way.
There are products on the market that measure lactate optically but they don’t currently provide as much detail. However, they may be a better option for some who only want to know the rough threshold.
Test – how to
To conduct your own test I would recommend teaming up with a friend. Remember that you generally need a 5 minute segments as a minimum to see a lactate ‘steady state’ forming. This is why Olbrecht suggests 1200m to 2000m intervals on the track with 1 minute rests (where the measurement is taken). If you friend takes the measurement you can turn around quickly. You can then return the favour and measure you friend’s workout after.
Even more economical is the ‘2 step test’ which just checks the general state of the aerobic versus the anaerobic capacity. You run the same distance twice – one at sub-maximal effort and once at maximal effort with 5 minutes rest before the test and 15 minutes rest in between the two.
Then you take blood samples in the 1st, 3rd and 5th minute after the sub-maximal run and in the 3rd, 5th, 7th, 10th and 12th minute or until the lactate drops (there is a delay in lactate reaching its peak after cessation of the exercise).
This would give you two points on a graph that you can plot a line in between.
The protocol I will be using with my co-coach in ChampionsEverywhere, Jason Kehoe, will look as follows:
Followed by a control test of the anaerobic system:
400m @ MAXIMUM effort
Then test every 2 minutes after until lactate drops. Voila!
Next up: some more perspectives on these insights