One of the new tools featured in WKO4 is the Power Duration Model (PDM). The PDM is an estimate of the relationship between time to exhaustion and work rate during both anaerobic and aerobic exercise. The main benefit of the PDM is having a robust mathematical description of your power-duration relationship. This provides quantitative insight into your unique abilities and paves the way for other useful analyses.

Why utilize a model to consider training and racing protocols? Endurance performance is limited by a number of factors, mostly oxygen transport, energy consumption, and neuromuscular power and economy of movement. Understanding how these systems both enable and limit your ability to sustain power over time is imperative to training success.

Training Levels
For training needs, the relationship between time and exhaustion can be divided into four groups according to dominant metabolism, which supplies energy to muscles:

Neuromuscular Power: 5-15 seconds. The lactate anaerobic metabolism is the basic energy system ensuring motor activity (phosphagen system).
Anaerobic Capacity Power: 30 seconds to 2 minutes. Motor activity of high intensity is primarily supplied with energy by the anaerobic lactate system (anaerobic glycolysis).
Vo2Max: 3-8 minutes. From this period on, the aerobic system is dominant, but the portion of anaerobic lactate metabolism can still be large (anaerobic and aerobic glycolysis).
Steady State/Endurance Power: Approximately 10 minutes to several hours. Motor activity is ensured by the aerobic energy system from more than 90% (oxidative system).
Power Duration models help us understand not only the overall relationship between time and power exhaustion but also how to prescribe training plans and workouts to create maximal results and adaptation.

Determine Rider Type and Identifying Strengths, Limiters, and Opportunities for Improvement
All cyclists have strengths and weaknesses. When working to improve your training and race or event performance, it is important to correctly identify your strengths and weaknesses and to use this knowledge to maximize and design both your training focus and your race strategy. The introduction of the WKO4 Power Duration model supplies you with numerous ways to review and identify your strengths and weaknesses, and the simplest method is phenotyping.

What is a phenotype? It is composite of a rider’s observable physiological characteristics and power individualities such as peak power, time to exhaustion and functional threshold power, expressed by grouping like individuals of similar traits. In WKO4 cyclists (and soon runners and swimmers) can be divided into four general phenotypes:

These athletes have a larger amount of fast-twitch muscle fibers and excellent ability to produce force on the pedals in a very short period of time (less than 30 seconds). They can be “explosive,” with incredible peak wattage in the first 5 seconds. A sprinter can also be more of a “diesel” sprinter with the ability to maintain a very high wattage for up to 20-30 seconds.

These athletes have large natural VO2Max power and can produce high watts from roughly 3 to 8 minutes. They typically can produce 120+% of their FTP wattage for 5 minutes, which is above the upper limit for the Coggan Classic Levels for Level 5 (VO2Max).

These athletes possess a fairly even blend of fast-twitch and slow-twitch muscle fibers. They might have a very good sprint (5-15 seconds) and can time trial well for an hour with a high FTP. They perform well in nearly all events; they’re not great in any single one but are always a threat to win. One important thing to remember about all-arounders is that they also have the ability to “change” phenotypes depending on the focus of their training. An all-arounder could spend a year working on his pursuit and become a pursuiter, only to spend the next year working on his climbing and become a time trial/steady stater. This is very common among all-arounders.

These athletes have a large percentage of slow-twitch muscle fibers and a high FTP, typically along with poor neuromuscular power. They can sustain their power output for a long time (more than 30 minutes) and exhibit excellent endurance for many hours. They are excellent in stage races, long rides, time trialing, climbing, and any event that requires a long, hard, sustained effort.

Customize Your Training

Now that you know the basic phenotypes, you can enhance your understanding of your strengths and weakness through in-depth review of your Power Duration model and comparing yourself against the standards. powerdurationcurve1

Using this new understanding, you can customize your training to achieve better results. Here are some basic rules to consider:

  1. Train your weakness, race your strengths. As you start building a training plan or workout, first focus on workouts that address your weakness. For example, if you’re a sprinter and sweet spot or tempo workouts are your worst nightmare, you need to do more of this work, particular early in the season.
  2. Limit the weakness work. As a caveat to rule 1, you need to limit the workouts that focus on your weakness, because they take a bigger toll on you. Find the right balance of adding workouts that focus on your weaknesses without creating a high level of fatigue, which limits adaptation.
  3. Keep building on your strength as your plan progresses. At the end of the day you’ll tend to win races by utilizing your strengths, so the focus is important.