Devil Prep - Phase 1: Overview

Devil Prep - Phase 1: Overview

Hello, and welcome to Phase 1 overview of the Devil's Staircase 50KM trail plan. If you missed the first post in this series, head back here and take a look, don't worry, I'll wait:

In this post, I'll give an overview of the first four weeks. Subsequent posts for this phase will just be more of a summary of the week, and how I feel it went.

As I briefly touched on in the previous post, this phase is all about adaptation. About getting the body ready for the work we're going to put it through. For me, this adaptation will be about the change in routine, and running days. I'll be moving from a Mon/Wed/Fri/Sun routine, to a Tue/Wed/Thu/Sat/Sun routine. The time on my feet during these four weeks will probably end up being slightly less than my usual maintenance load. This will give my body that extra bit of time to recover, while adding in an extra training day, helping me build the routine.

So, what do these first four weeks look like?

An Overview

On the left, you can see a high-levl overview of what this adaptation phase is going to be. It's rather simple, a little repetetive, but key to laying a good foundation for what I'm about to do to myself.

I've got four weeks, each with an 80% load of easy runs, and 20% long runs, which will be done in my Power Zone 1. This is 65 - 80% of my Critical Power, and generally lines up with Zone 2 of my Heart Rate Reserve, which is 60 - 70%.

On the right you can see a bit more of a breakdown on how this looks for week 1. This whole month is pretty much identical, apart from a slight increase in duration.

  • Monday will be rest and recovery day's. Although, this doesn't mean laying around like a slob, doing nothing
  • Tuesday will be a short easy run
  • Wednesday will be a short easy run
  • Thursday will be a short easy run
  • Friday will be a rest and recovery day
  • Saturday will be a long run day - still easy, just longer
  • Sunday will be an easy run, about two-thirds the length of the long run

This is what the calendar looks like (apart from that first day, I forgot to take a screenshot before uploading the first run so I grabbed the one from below).

Also, ignore the day numbering. Because there was an extra week in my schedule when I applied the plan, it added extra days in and technically thinks I've already done a week ...

My Current Numbers

Above, I mentioned things like percentages of Critical Power, and Heart Rate Reserve, what are they?


Great question, and one that is probably left to be explained by people far more knowledgeable than myself. So, if you want to get a little nerdy, head on over to the Stryd FAQ on Critical Power: - I'll use their definitions around power, as that's the power meter I'm currently using.

But, in short (because pretty much everywhere else jumps directly in to the "I'm more intelligent than you" style talk), Critical Power is the energy my body can produce for a certain period of time before fatigue starts to get the better of me. At this point, I will no longer be able to maintain that number. For me, that number is currently 243W.

That puts me at 4.22W/kg (yep, I'm tiny), and gives me a power zone breakdown of:

  • Zone 1 Easy 65-80% CP: 158 - 195W
  • Zone 2 Moderate 80-90% CP: 195 - 219W
  • Zone 3 Threshold 90-100% CP: 219 - 243W
  • Zone 4 Interval 100-115% CP: 243 - 280W
  • Zone 5 Repetition 115-300% CP: 280+W

With that bit covered, we'll move on to how this looks over time on the power duration curve, which shows what power I can run at, and for how long.

From a minute onwards, the modelled ability (white line) is actually rather accurate most of the time. I haven't done any 10-second flat out sprints for a while, so that's reflected here. I may have to have a play on the grass track soon to do some of those.

On the right-hand side of the above graph, you can see how I compare to the average of other Stryd users in my age and goal distance bracket.

  • My Fitness is based on my Critical Power. The average is currently 3.68 W/kg, putting me above average (that makes a change!).
  • My Muscle Power is based on the peak 10-second continuous power. The average here is 5.53 W/kg, with me being able to produce 6.30 W/kg. Another one I'm above average in, whoo!
  • Fatigue Resistance is based on the duration I can maintain my target race power. I'm below the average here, which is 1:28:16. As I get a little further in to the plan, I expect this to increase dramatically.
  • Endurance is based on my longest continuous duration above 50% of my Critical Power. I've not really done any runs much over 1.5 hours for quite some time, so this is reflected here with me being under the average of 2:16:50. Again, once I get further in to the plan, I have long runs that far exceed this, so I also expect dramatic changes here.

As this race is all about endurance, I wouldn't be surprised to see my critical power number drop slightly, along with my muscle power. While my fatigue resistance, and endurance improves during these 18 weeks.

Heart Rate Reserve

On to Heart Rate Reserve,  HRR for short.

Previously, I'd always worked my heart rate zones using the % of max heart-rate. That was until I started consuming information around the Lydiard style way of training. HRR is used by many different styles, it just so happens that this was what highlighted it for me.

HRR is the difference between your resting, and your maximal heart rate. You'd subtract your resting HR from your max HR - this gives you your HRR. You would then create your zones from this number. For me:

RHR: 49
MHR: 190
HRR: 190 - 49 = 141

Great, I have my HRR number. Now I can figure out the 60%/70% ... Who am I kidding, my maths is horrific. There are plenty of tools for this, and I've got Garmin as mine (if you'd like to know why I'm in the Garmin camp these days, you can read my moan about Polar here:

And just like that, my HR zones are filled out and updated on my watch. It knows my resting and my max already, all I had to do was change what it was based on. It almost feels like cheating.

I've always had a high heart rate while exercising, some people do. Basing it off a % of max, things would always put me in a threshold area HR-wise, even when trying to go easy, I'd be in to the upper end of the lower zones (doesn't help that there are no flat surfaces around here). HRR has changed that, and also seems to be more accurate for me.


Since I committed a little more to working with power, pacing has mostly been forgotten. Sure, it's nice to see a fast pace, but when all you run on is hills, it's just impossible.

As an example; If I run at 180W on the (relative) flat, my pace could vary from a 9min/mi down to 8:30min/mi. Add in some head-wind, that could increase to 9:40min/mi. If I were to attempt to maintain that 8:30 pace during a warm-up, regardless of wind or elevation, my HR is going to go nuts, flying well outside of the easy zones, and increasing my power output to over 200W. That could be putting me in to the moderate, or even threshold zones during my warmup. Not ideal...

Throughout this, I may reference my pace from time to time, but it's certainly not what I'm basing things on. This plan is based on power, and duration.


So, I guess that's it. You've seen the first four weeks, a breakdown of what that week looks like. A long with my stats, where I'm starting, what zones I'll be working in.

Perhaps not the most informative, and a little scattered, but hey, I'm not Shakespeare. If you want perfect, professional grade writing rather than mind dumps - you're in the wrong place.

Let me know if there's anything else you'd like to know!

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