I actually completely forgot I wrote a post on Polarized Base last year, as I understood it at the time. I’d probably like to go back and change a few things, but it’s a good starting point to understand the theory.
For the last two years I followed a more time-constrained Sweet Spot Base training plan (via TrainerRoad) which got me good results, but didn’t address some of the underlying physiological constraints I identified, namely that I’m not optimally adapted for endurance sport.
Relevant Physiological Weaknesses
- Short endurance training history: I’ve only followed a specific cycling training program for two years, starting in the 2015 season. I don’t have a broad Aerobic physiology built from years of experience.
- ANaerobically-dominant phenotype: I played Rugby and lifted heavy things all through high school & university. I have a lot of muscle mass, lots of fast twitch muscle fibers and I put on weight easily. I’m a classic Meso/Endomorph (are these phenotypes still scientifically accepted?)
- Poor Stamina & Fatigue Resistance: I can’t put out the same kind of power at the end of a race as I could in the beginning.
To address these factors I basically need to play catch-up with a large volume of pure Aerobic training. I have 12-15 hrs/wk to work with, and that should be plenty – if I’m training efficiently – to accumulate Aerobic physiological adaptations.
So I began a training plan that would have me spending the vast majority of my time over the first 8-weeks smack at the top end of Zone 2. I monitored both Power and HR to ensure I was hitting the desired Aerobic energy system. This is where HR training is still valuable: to determine how efficient my cardiovascular system is at a given workload, and how it changes over time
Relevant to the topic of whether long slow “traditional” Base training is necessary to affect the kind of physiological adaptations I was looking for. Start with the first two episodes of the Velonews Fast Talk podcast.
My Aerobic Threshold heart rate, as determined by lab testing, is around 147 bpm. In order to target my Aerobic energy system I should keep the physiological stress just under this threshold. Since this threshold is slow to change, I was happy to use 147 bpm as a constant.
So I would aim for improving Efficiency Factor – Cardiac Efficiency – at this Aerobic threshold HR.
These charts show the volume of Aerobic training through my Base training phase and the resulting improvements to cardiac efficiency.
- Note: Much of the volume apparently spent in Power Tempo Zone 3 in the first chart was actually under my HR Aerobic threshold, so should be included as Zone 2.
- The duration spent in HR Aerobic z2 (77 hrs) vs Power Z2 (62 hrs) is an indication of this discrepancy.
- I probably spent close to 80% of my time during this period under my HR Aerobic threshold.
One of the other key indicators I used to track cardiac efficiency and ensure I was targetting the top-end of my Aerobic zone was with a post-workout analysis of my Standardized Warm-up, which I discussed in depth here.
Results so far
My average ride Efficiency Factor has improved from 1.55 W/bpm to 1.76 W/bpm over the first 8 weeks of Aerobic Base. This came from an initial rapid increase in power as my body re-adapted to training after the off-season, then the slower improvements of true physiological adaptation as I was slowly able to push my power up under HR Aerobic Threshold.
I took a lot of pride in being able to bump up my power during some particularly fresh workouts, cruising along at 250 W with my heart rate nicely in the 140’s and breathing through my nose. It’s no pro-level endurance just yet, but it marks a significant improvement in one of my targeted weaknesses!
Adding VO2max drills
The polarized component of my training would come in the form of VO2max drills, to target and raise the ceiling of my maximum Aerobic capacity. Next I’ll discuss how to train VO2max and how I implemented high intensity interval training into my Base plan.