2017 Training Part 4 – Sweet Spot

After spending 8 weeks of Aerobic Base and VO2max to work on my physiological limiter of peripheral muscle Aerobic adaptation, I transitioned into Sweet Spot Training (SST) to continue to push my FTP up from below.

I’m writing this with a week and a half still to go of Sweet Spot. This can be considered a follow up to my first post this year on FTP and TTE testing.

TrainerRoad has a bunch of good articles explaining Sweet Spot training protocol. FasCat Coaching has an excellent primer on it as well. The Sweet Spot zone is meant to balance intensity, volume, repeatability, and recoverability – It is hard enough to push your system to adapt and get fitter, while allowing you to rack up plenty of volume both during a single workout and over the course of a week.

This sample week from TrainerRoad’s Sweet Spot Base plan has over 2 hours of SST with less than 7 hours time commitment for the week

SST has different percentage cut-offs depending on what source you refer to, but broadly Sweet Spot is just under your threshold – around 85-95% FTP. Think of it as pushing your FTP up from below.

Power-Duration Model

Without getting to far into the weeds (there’s plenty of good articles for that) the evolving WKO4 Power-Duration model is an attempt to quantify the relationship between a rider’s potential power output, and the duration for which they can sustain that output.

This is where FTP and TTE (Time To Exhaustion) come into play.

Customized WKO4 Power Duration Curve chart

Extensive & Intensive PD Model

Because every duration has an associated predicted (modeled) and demonstrated Peak Power, it becomes a two-dimensional model of fitness. To get fitter, you want to push the PD curve either out – ie Extend the duration at a given power output, or push it up – ie. increase power intensity at a given time interval.

I made a choice – basically a value judgement – that longer power was more valuable to me than higher power. If you’ve read some of the posts I’ve written so far in 2017 you can piece together than a limiter for me is my sustainable pure Aerobic power; ie power out beyond 20-minutes where I can’t ‘over-test’ by relying on my predominant fast-twitch/ANaerobic physiology. So for me Sweet Spot training would be about Extending my FTP out beyond ~45min.

The start of this mission was to complete a TTE Test (I’ve linked to that post enough ) where I would hold FTP for as long as I could. I managed 318 W for ~50 minutes. This gave me a target power and duration for SST intervals.

First SST workout of the new year
  • If you recall, I wrote initially that I thought 50-minutes at 95% as WKO4 suggested, would be too difficult.. mentally and physically.
  • I modified the Intensity to the mid/low end of SST at 90% and went for 50-minutes cumulative work duration over two 25-minute intervals
  • I gave myself 2-minutes rest between the work intervals, more for mental recovery than anything! It helped, and you can see my HR continued to rise smoothly during the second interval.
  • This felt challenging, but not exhausting – just as SST is supposed to feel!

Over the following few weeks I’ve increased the duration of my work intervals to 30-minutes, giving myself 60-minutes cumulative at Sweet Spot. My power also increased as I raised my FTP after a successful MAP test (I also changed power meters around this time that skewed the numbers a bit… long story, worth a future post) but my target remained at 90% FTP.


The full SST Extensive Interval

Over the next week I’m going to increase my intensity to 92% FTP and complete a single SST set of 45min, at my current TTE. I have a feeling that again this will be more mentally challenging than anything.

165 TSS in 2.5 hrs is serious…

2 thoughts on “2017 Training Part 4 – Sweet Spot

  1. Information overload, but I love reading your blog. Thanks for posting a little more frequently in the last few months. For someone just starting out, first Cat 5 race in April. Would you recommend mostly SST? I did base last year, about 2,500 miles in Z2 (Heart rate zone). I’m now on Zwift, but not sure what the outcomes would be from those various training programs they have on there. I have about 6-7 (my average for the last month on Zwift)hours to train right now until the snow melts. Appreciate it.

    Liked by 1 person

    1. Hey thanks!

      Yeah these posts have tended to be massive info-dumps. Gotta work on making them more accessible 🙂

      Yeah I would recommend Sweet Spot training for most cyclists as part of Base Training – it adds a good amount of aerobic training load without burning you out. Especially if you can’t get in the 4 hour Stamina rides due to time or weather constraints.

      Some other great information on SST here: https://fascatcoaching.com/tips/how-to-sweet-spot/


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