Load and Performance


One of the most common requests I receive as a coach is to don my prognosticator hat and answer the question “How fast will I go on race day”. This question can take various forms, from the direct “Will I qualify?” to the subtle “What’s an appropriate pacing strategy?” but the inquiry is fundamentally the same – based on the training that I’ve done, what are some realistic performance expectations? Or, the flipside to that, ‘if I have xyz performance expectations, how much training do I need to do?’

The truth is that, as Zatopek observed back in the day, to a large extent training remains ‘principally an act of faith’. There are so many variables, some fitness related, some not that make up a given performance on a given day. In order to make even a decent guess, I need an intimate knowledge of a given athlete and their training history. It is a huge over-simplification to assign volume targets for different ‘categories’ of athlete and yet, with the exception of the coaches who whole-heartedly embrace mathematical modelling of the training process, this remains the go-to paradigm “You want to qualify for Kona? Take 20hrs a week and call me in the morning.”

There are a few flies in the ointment with regard to the load:performance relationship that make this an unsuitable approach…

1. Quantifying Load For Different Intensities And Different Sports

In the interests of simplicity, many coaches and athletes continue to look at load from an “hrs per week”  perspective. In reality there can be a huge difference in training load between a 20 hour base week for a good level age group athlete and a 20hr specific prep week for a competitive ITU athlete. Factor in the additional difficulty of quantifying the effect of a big run week vs a big swim week and attempting to discern a load:performance relationship  based on hours of training becomes a futile task.

2. Delayed Training Effects

The cold, hard fact is that training load doesn’t show up immediately to benefit performance. In fact, when it comes to training, things are likely to get worse before they get better. You get different performance benefit from training depending on its proximity to the performance date, as explained here (http://www.endurancecorner.com/Influence_Curves). For this reason, total training hours over the course of a year tell us very little without further info as to how they were distributed and an athlete who is ‘smarter’ in the way they distribute load can beat an athlete who accumulates load in a non-deliberate way.

Both of these factors come into play when determining the performance benefit that an athlete can expect from a given load but the biggest principle that must be factored in when predicting performance from load is that of….

3. The Principle Of Individuality

This is the really big fly in the ointment that has caused many a coach to throw up his arms in frustration or, worse than that, to attribute the failure to the athlete – ‘you just don’t have it, Kid’ ‘choose your parents wisely’  etc etc.

Even if we are able to accurately quantify true load and accurately discern the general fitness effects of training at a given point in time to some performance in the future, no two athletes will respond exactly the same way to this load.

The more astute coaches have recognized that different athletes respond differently to the same load and rather than adhering to ‘what we’ve always done’ have tailored their programs to the particulars of the athlete. Folks like Terrence Mahon, Bill Sweetenham and Brett Sutton are masters in using their experience driven intuition to ‘size up’ an athlete and design their training load accordingly.

With the advent of dose-response modelling techniques, these differences in the individual athlete’s rate of adaptation to a given load have for the first time been able to be quantified. This is a big part of what I do as a coach. I prescribe load, see how the individual athlete responds and then ‘tweak’ the individual athlete’s constants so that I can come up with the best combination of load that will lead to the highest performance on a given date.

While the use of software such as wko+ and RaceDay goes a long way towards addressing the first 2 issues, the only way to adequately answer the 3rd problem of individual response to training is to spend a lot of time with an athlete observing their response to different amounts and forms of load.

Keeping the above limitations in mind, I thought there may be some interest in the ranges of load:performance relationship  that I am observing in CTL (Chronic Training Load) terms. Again, this is a dramatic step up  from trying to express load:performance relationships in terms of  hours  because it takes into account:

  1. Relative quantities of  training load for different sports  and intensities
  2. The effect of training at a given point in time on performance at some point in the future.

The table below illustrates typical combined CTL (chronic training load) numbers that I am seeing for different levels of athlete. For more on CTL, click here.


As you can see, each (performance) level encompasses a pretty wide (load) range due to the factors mentioned at the beginning of this piece. A couple of tips to help with applying these numbers to you….

  • Older athletes will typically require more load for a given performance, i.e. they will fall toward the top end of the range. ‘Older athletes’ in my sample are 45-49. ‘Younger athletes’, those typically falling toward the bottom of the sample are 20-29. Considering CTL tolerance for most folks is limited to  ~150TSS/d, you can see how age can become limiting at the top levels.
  • Smaller athletes will typically require more load for a given performance. Athletes with more natural muscle mass require (and can tolerate) less load to hit a given performance.
  • Female athletes will typically require more load for a given performance.

The middle of these load ranges will be appropriate for ‘average’ sized males in their 30’s.

In real world terms, these ‘chronic’ load numbers mean that an athlete will have a 3-5 month block of training at the appropriate level at the appropriate time. For a top age-grouper training at an average steady intensity this equates to ~20 weeks in the 18hr range if flat loaded. However, as mentioned, the real value of modelling lies in getting the most performance bang for your training load buck by manipulating load so that it happens in the right amount at the right time. More on that to come in future blogs….

Train smart.

About the Author

Alan Couzens

Alan Couzens, M.S (Sports Science) is the team Exercise Physiologist/Coach with Endurance Corner in Boulder, Colorado. Alan advises top age-groupers and professional endurance athletes on how to apply the latest in exercise science to get the most from their training.

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