Building my Fellrunning Season: Part 2
Turning test results into a prescription for training intensity
In Part 1, I outlined how I will be using both regular maximal and submaximal testing to give me an evolving view of my fitness over time.
My initial round of maximal testing is done, I have a velocity curve. In this next part, I’ll detail what I’ll actually do with this and how it translates into a training prescription.
But first, we are yet to agree on universal naming and definition of various thresholds and other physiological terms, so here are a couple of definitions for understanding what I mean when I say X.
vVO2MAX
The speed achieved at the end of a VO2MAX ramp test, or in my case, the speed I achieve in my 3-5min maximal effort test.
Critical Speed (CS)
Maximum sustainable speed for 30-40 minutes (can be calculated using the testing protocol outlined in Part 1 of this series). The physiological threshold that CS represents has many names and different physiological markers that will place it slightly differently; anaerobic threshold, maximal lactate steady state, second ventilatory threshold.
Lactate Threshold (LT)
The point at which blood lactate concentration rises 1mmol above baseline. Also called the first lactate turnpoint, usually correlated with the first ventilatory threshold. Generally would be the top of Zone 2 in a 5 zone intensity model.
Initial Test Data
Tests were done in the same week on Monday/Thursday on a treadmill set to a 15% gradient.
To sense check the outputs, I used two different graded pace calculators to convert to a flat ground equivalent and took the slower of the two converted paces. In this instance, they appear fairly accurate, my CS flat estimate is actually just 1 second off my PR 10k pace.
Short test
Duration: 4min06sec
Speed: 10.5kph
Flat equivalent: 20.4kph / 2:57/km
Long test
Duration: 15min
Speed: 9kph
Flat equivalent: 17.5kph / 3:26/km
Critical Speed
Estimated duration: 30min
Speed: 8.4kph
Flat equivalent: 15.8kph / 3:48/km
My resulting velocity curve.
Simply by testing every 4-6 weeks, and updating this curve, I will be able to see with certainty if I am actually getting faster or not.
Importantly, I also need to pay attention to the relationship between the individual test results. The gaps will highlight limiters and show how my fitness changes shape.
Whether the gaps are shortening or widening indicates if my training is proportionally more effective in improving top end or sustainable speed.
Short-Long Gap: -14.29%
Short-CS Gap: -19.66%
Long-CS Gap: -6.27%
Broad Training Prescription
All of this needs to be framed within my race goals - ultimately the intensity I care most about is race pace. I want to run for ~2.5hrs as fast as possible, an intensity that will be just above LT, adjacent to a marathon pace effort.
It is a simple fact that I cannot be faster at LT than I am at CS, so CS is a race pace limiter. Similarly, CS cannot be faster than vVO2MAX, so this is the CS limiter. This paints the picture of periodisation, moving from general to specific. Raise vVO2MAX (least specific) to create room for subsequent improvement in CS (somewhat specific), followed by focusing on race pace at ~LT (most specific).
As of right now, there is a healthy gap between my short test (representative of vVO2MAX) and CS of 20%. A fair bit of headroom for improvement in my CS, I could probably drop the vVO2MAX work, focus on CS, and see good improvement.
However, I am still a long way from race day. If I close that gap up now, it might limit my ability to raise CS later on. Then I’ll have to do some vVO2MAX work to ‘raise the ceiling’. This would not be ideal, breaking the golden rule of periodisation - most general to most specific.
My goal race is ~2.5hrs, so running at vVO2MAX is definitely not specific. I want to do that work predominantly early in the build up to maintain that nice 20% gap, so when the time comes for CS development, it has plenty of room to improve.
You might notice there’s only a 6% gap between my long test and CS. This isn’t really a concern in the same way it would be for the short test to CS. While the 15min test is valuable as an indicator, that is all it is - an indicator.
While the short test is a reasonable marker for my top end speed, and CS the border between sustainable and unsustainable, there is no physiological threshold at 15min. It’s used simply to calculate CS in a lower stress way than running a maximal 30-40min effort.
The tail shouldn’t wag the dog, if my CS is improving, it should show up in the 15min test, rather than specifically trying to improve my 15min performance in order to get a higher calculated CS.
As the weeks pass, I have to advance the training into more specific phases dictated by how far out I am from the goal race, assuming I allow a minimum of 6 weeks for each block.
Alongside measuring the effectiveness, testing allows me to tailor the periodisation should I see a plateau in improvement for the primary focus of the block. I’ll be able to make an informed decision whether to change the structure/volume of training, or advance into the next phase.
Largely, it’ll come down to how much longer I can afford to spend in that block. If I’m 8 weeks out from race day, there won’t be much I can do for a plateau in CS before I need to shift toward a focus on race pace.
My basic week
Each week throughout the season I am working on three thresholds; lactate threshold, Critical Speed, and for the purpose of this, I’m treating vVO2MAX as my uppermost threshold. How much training time is spent on any one of these is dependent on the phase of training, and the shape of my velocity curve.
Regardless, I’ll touch on each threshold every week, something that Dr. Philip Skiba1 strongly advocates for.
Firstly, to improve across the entire curve during the more general phase of training.
Second, to maintain gains made in previous blocks (or at least limit losses) in the more specific phases.
Finally, because last year my uphill speed stagnated without doing work at higher absolute speeds, so this year I’ll experiment with keeping some flat, fast intervals throughout (read more about how going uphill all the time does not necessarily make you faster uphill).
Also, I will be doing B and C races throughout the season, so it should keep me in better shape for faster efforts than a more traditional “all easy” base period would.
What that looks like in practice per week:
Mon - easy / intervals @ vVO2MAX (approx. speed in 3-5min test)
Tue - easy / steady hills
Wed - easy
Thu - easy / intervals @ CS
Fri - easy / steady hills
Sat - 2-2.5hrs steady hills w/ tempo intervals (85-95% of CS)
Sun - off
Easy: well below LT, basically a jog
Steady: Close to LT, but remaining below
Durations of the runs will fluctuate as I build volume (the subject of Part 3) and depending on day-to-day feeling, but this is the basic structure I’ll use.
Pace prescriptions for all intensities are based on the testing. My intervals (except those inserted into the long run) are all done on an 15% incline treadmill, so can be applied directly using test values. There won’t be a requirement for much guesswork here, I’ll know exactly what pace I should be hitting.
There will of course be plenty of running out in the real world on variable terrain. Pace for these runs will be based on a combination of HR and RPE. This is very individual, but let me briefly pat myself on the back and be optimistic that I am fairly well dialled into an easy - steady - tempo feeling (greatly benefited by a lactate profile last year). This is supported by HR data, which I can marry up to the normalised graded pace that TrainingPeaks calculates.
There is certainly some face value complexity in this approach to intensity, but the use of testing lends clarity to what would otherwise be a series of educated guesses. Test to gain insight into fitness and race pace limiters, address limiters from least to most specific, retest to measure progress and update training paces.
In part 3, the topic is training volume. In parts 1 & 2, I’ve created the skeleton of my season, next I’ll put some meat on the bones. I’ll discuss how much of each intensity I’ll do, and how I make those decisions.
If you don’t know who this is, he was part of the team behind Breaking 2 and he is well worth looking up. He has made numerous podcast appearances, which I have listed at the end of Part 1 of this series. His book, while tricky to get outside the US, is also an incredible resource.