Physiological vs Performance Training

As I’ve thought about how I structure my training, I’ve drifted toward a periodization model with two broad areas of focus: Physiology, and Performance

Physiological Training: where the focus is on improving physical fitness, endurance, mechanical and metabolic efficiency, etc. via structural and biochemical changes to your physiology.

Performance Training: where the focus is on improving your racing ability via training for the specific demands of your target races, improving your mental and physical ability to “suffer”, gaining race experience and confidence, and otherwise sharpening your fitness to a ‘peak’ performance.

To me, it seems like your physiology is only the first component of racing a bike at a high level. It’s your ticket to the start line. There is certainly a minimum necessary fitness level to reasonably expect to be competitive (or just survive) your target race, but what you can do with the fitness you have plays a far greater role in determining the outcome of your race.

The highest VO2max doesn’t win races, nor does the greatest Watts per kilo (except, maybe on Zwift..).

Science and Art

I’ve spent more of my time looking at Physiological Training, since I perceived that as being my first limitation to be able to compete at the level I wanted to race at.

This also aligned with most of the literature on Endurance fitness, where I felt comfortable investigating, interpreting, and prescribing training protocol based on the body of research available.

However, while empirical studies are very good at measuring and assessing change in physiological characteristics – VO2max, lactate accumulation, mitochondrial respiration, muscle composition, hormonal environment, etc. – these characteristics are not necessarily well correlated to actually winning races.

There is a much more limited understanding in the literature of how these measurable characteristics translate into winning performances on the road. Hence, differentiating between Physiological and Performance training.

If the literature reveals the process of finding the optimally efficacious training strategy, Coaching is the process of applying the optimally effective training strategy for an individual athlete. The science, and the art of application, if you will.

Broadening Fitness with Physiology

I treat winter Base as the time for Physiological Training. This is the time to build the Aerobic engine – or even more fundamentally, the chassis into which the engine has to fit.

This is where structural changes to endurance physiology are achieved. And where VO2max can be used as a valid metric to quantify and measure change.

My opinion based on what I’ve read in the literature is that Polarized Training is the best way to achieve sustainable, long-term, structural adaptations that will improve Endurance fitness.

Polarized training appears to be the best way to maximize adaptations without over-fatiguing, or burning out too early in the season. Athletes seem to benefit from the relatively low volume of high intensity, which is easy to maintain over the winter. And low-intensity feels “easy” and comfortable enough to be done in a high volume and frequency (but seems to offer benefits even at relatively low volumes)

Sharpening Fitness with Performance

As you get closer to your target races, Performance Training should become more race-specific and reflect the demands of your target events. This is where I think Tempo, Sweet Spot (SST) and Threshold training play an important role.

SST & Threshold intervals are mentally demanding and require both fitness and focus to sustain. I prefer to work on extending my power-duration curve at FTP from below, by spending longer (>20min) intervals in Sweet Spot.

For my Stamina Rides, I would start to add much longer intervals (60+ min) above the Aerobic Threshold, into Tempo zone. I find riding above Aerobic Threshold surprisingly more fatiguing and likewise mentally harder to sustain for long rides.

It seems to me that SST/Threshold and Tempo training are less efficient in terms of optimizing adaptation/fatigue trade-off, but these are race-pace efforts that you need to perform on race day.

Performing on race day requires both peak mental & physical fitness

Is this Reverse Periodization?

Reverse Periodization is a model that has been (still is?) popular with Cyclists & Triathletes. It’s based on doing more intensity over the winter, and more Base-like long-slow-endurance riding as the weather improves toward the beginning of the season. I haven’t done any substantial research into Reverse Periodization, but at best I’m ambivalent toward it.

I think my conception of Physiology & Performance Training, and prioritizing Polarized VO2max training through the winter isn’t quite Reverse Polarization, and isn’t quite ‘normal’ Periodization. But it takes a bit (hopefully the best bits) from both.

Physiological Training over the winter is spent either working very easy with Aerobic training, or very hard with HIIT (VO2max) training. And the transition toward Performance Training allows the intensity to converge toward the middle with Threshold and race-pace efforts.

Where do Other Energy Systems fit in?

I haven’t touched on the other major energy systems as much, simply because my own focus has been on Aerobic and VO2max for my current training blocks. But depending on your ‘natural’ physiology and your particular limiters, you may want to devote more focus toward Anaerobic or Neuromuscular efforts.

Anaerobic training would certainly fit into a Polarized Physiological Training block, where your hard workouts would be doing even harder and shorter AN intervals (sub-1min work intervals with long recovery intervals between efforts).

Neuromuscular efforts fit even more easily into a Polarized training plan, as these short, nonmetabolic sprint intervals can be thrown into a long Aerobic ride without inhibiting the target adaptive benefits (and possibly reinforcing them).


The Physiological/Performance Training model can be applied to an existing training plan without necessarily changing the timing of any particular training blocks. It can be used as a way to clarify the target goals and intent of the current training block, especially with no imminent races or target events coming up to motivate your training.

I don’t think there’s much to be gained by me trying to turn established periodization theory (Base > Build > Peak > Race) on it’s head, where the proof has been in the winning performances of thousands of athletes across sports, at all levels. That’s not what I’m trying to do.

Instead I think the Physiological/Performance Training model is an effective theoretical framework to align average best-practices as suggested by the literature with best coaching practices applied to real-life athletes.

7 thoughts on “Physiological vs Performance Training

  1. Jem,

    Hopped over here from r/velo and I’m happy I did so. I’ve read your three most recent posts and I must say you’ve really got some good content here, so first and foremost thank you for putting this all together!

    Now, I think I’ve digested all the information thus far and I’m left with a couple questions on how to apply this style of training to myself, and to others like me who aren’t racing competitively ( least not yet), but enjoy seeing continous improvement and want to get in the best shape possible with the time we have.

    You explicitly state that this periodization method is effective with 80% of the training taking place in the Aerobic zone, while the other 20% should consist of VO2max high intensity interval training.

    My question is….since I’m not a racer, I’ve only been riding for a year (3.7 w/kg ftp @ 65kg currently), and I’m more of a climber than a sprinter…how should I be structuring the 20% HIIT portion of my training to get the best improvement? Are VO2max efforts the go to? Or could I swap in some threshold and sweet spot as well to keep building those systems?

    Basically, I feel like my first year of riding was done so with no real rhyme or reason, except that I’m naturally competitive with myself so I ended up going after a lot of my own PR’s up some of the local climbs as the year went on. Most of the climbs are in the 7-15min range, with 1 or 2 longer climbs closer to 30 minutes. Is it best to target one system at a time, or could someone do one VO2max workout and one FTP workout each week and see improvement in both?

    Lots of questions, I know, and feel free to answer more generally if I was too specific. Thanks again for effort you put in and I look forward to what’s to come 🙂


    1. Thanks! Glad you got some value out of the posts!

      So let me try to answer your general question “what should my HIIT workouts look like?”. I should be more explicit.. Polarized Training (POL) is more effective at improving FTP than doing FTP intervals, all else being equal.

      If you think of POL as working either near the top of your Power-Duration Curve (VO2max), or near the bottom of your PD Curve (AeT), and avoiding ‘moderate’ SST/Threshold intensity, you will pull the entire curve up from top and bottom, so that FTP comes right up along with it.

      If you tried to add an additional SST workout to replace an easy workout, the literature suggests you’d accumulate too much fatigue for your next HIIT workout to be maximal quality. If you replaced a HIIT workout with SST intervals, the assumption is you’d gain less adaptive benefit than if you did another HIIT workout.

      VO2max is a reflection of your entire Aerobic system, which will always be the most important energy system to endurance cycling. But depending on your individual characteristics as a rider (eg. how aerobically adapted you already are, your muscle fiber type composition, other training & genetic traits, etc.) you may want to also focus on your ANaerobic system as part of a Physiological training block. One of my athletes is starting with VO2max but will be doing an ANaerobic block as this is a personal limiter of his. Another is basically going to avoid touching ANaerobic until Performance Training, since his ANaerobic system is already highly developed and his limiter is Aerobic fitness.

      There are plenty of valid arguments to mixing moderate & high intensities, and Sweet Spot Base (a la TrainerRoad) is absolutely a valid method to get fast! Research is limited in how well it can measure, predict, and reproduce the actual demands of racing. That’s why I say Polarized Training seems optimal for improving measurable indicators of Aerobic fitness but is insufficient for maximizing your ultimate performance out on the road.

      Also, quick note.. the 80/20 split is kind of deceptive.. it’s more a guideline to planning number of workouts: eg. If you have 7 workouts in a week, 1-2x should be high intensity (7 * 0.2 = 1.4). I’ve talked about previously how 2/7 HIIT workouts is kind of a ‘soft-maximum’ per week for high intensity. By time, the actual duration spent near VO2max is more like 5% of total weekly duration. You can imagine that in a 60min VO2max workout you’re not spending 60min @ VO2max, but that counts as 1/7 of your workouts toward the 80/20 split.. hope that makes sense?


      1. Jem, thanks for all the clarification, that cleared things up perfectly!

        Also, is there somewhere I can go to find details about the coaching services you offer, assuming you take web-based clients? At the moment i feel capable enough to continue training on my own over the winter and into spring, but I’m interested in developing a long term plan / getting a coach at some point next season.



      2. Cheers Chris! Yeah, I do some coaching (more like.. training analysis & optimization), but that’s not my full time job (yet?). So I haven’t really publicized it or created an online portal for taking on new athletes. I want to move in that direction, and I’ll put you on ‘the list’ for if/when it happens and if you’re still interested 🙂


      3. I’ll put you on ‘the list’ for if/when it happens and if you’re still interested…

        I’ll be second on the list!


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