Endurance Training Score (ETS)

Ergo Training

Adrian Cassidy

Introducing Endurance Training Score

The next step in monitoring rowing training

This is a feature we are currently developing. Our sophisticated users, who train with Heart Rate bands on a regular basis we feel this will bring a new insight into rowing training.

What is Training Load?

Sport scientist's have been trying to quantify training since Bannister first introduced the TRIMP model way back in 1991. TRIMP stands for TRaining IMPulse and uses heart rate measures and time to estimate a training load for any given activity. The major benefit to quantifying training is so that you can more accurately plan training as well as retrospectively assess a single training session or the volume of work completed in a 4 week cycle . The TRIMP model uses and individual's heart rate response to exercise which ensures that the majority of rowing training can be quantified. Where heart rate has its limitations is in the time lag that it takes to register when external work is actually being done and as such it is really only valid for steady state exercise lasting 2 minutes or more.

When the exercise duration it's less than 2 minutes or intensity is near maximal the quantification of external work done using heart rate response typically under-represents the true nature of the exercise. The limitation described here with heart rate is where power metres have gained so much attention. Power meters quantify external work considerably more accurately as well as responding immediately to the force being produced. As such power metres are seen as the gold standard for measuring external training load and every other measure is a less accurate alternative with its own inherit set of limitations. Unfortunately at the moment power meters (WEBA, Peach Innovations, NK) for rowing are reasonably expensive, problematic to ensure long term installation on a rowing shell and not focussed around quantifying training but more directed towards the biomechanical analysis of the rowing stroke. The sport of cycling has created a opportunity to show rowing exactly what can be done with the everyday use of power meters; it is now routine for cyclists of all categories and experience levels to use power metres to capture training and racing data. In the future I see a time where rowers will collect data from training and racing much like cyclists do now however there is a long way for the reliability of the technology to move before this happens for us.


Rowing Training

Rowers undertake a large volume of training in a wide variety of disciplines (rowing, cycling, running, swimming, skiing, conditioning, weights etc). Power meters are unable to collect training load information from all of these disciplines and as such rowers need simple measures that span all of these modalities. In the past simple measures such as time spent training and distance travelled have been used to plan and quantify rowing training. The main issue with these basic metrics is that 1 km of rowing does not equal 1 km of cycling both in terms of time and and perceived effort to the individual. A perfect example of this would be to ask a rower which task is more difficult; rowing 10km at stroke rate 20 on the water or rowing 10km at stroke rate 20 on the ergometer. Most if not all rowers and coaches that I have spoken to will answer that rowing on 10 km on the ergometer is significantly harder than rowing 10km on water regardless of whether the stroke rate and or heart rate are similar.

Herein lies the biggest problem when quantifying rowing training; how can rowing training over a number of training modalities be summarised back to a simple number that can illuminate the training load?. At the national training centres in Australia Elite rowers will regularly undertake on water rowing, ergometer rowing, running, indoor cycling, outdoor cycling, strength and power weights, strength endurance weights, muscular conditioning, walking and swimming. Trying to find one training metric that encapsulates all of those activities as well as understanding that rowers are efficient at rowing and not as efficient at running is extremely difficult.


A better understanding of actual training

We are finally getting to a point where we are able to easily measure training at a very detailed level without disrupting the athlete in any way.

What does ETS actually mean?

With this problem in mind I developed T2 minute training load score which ROWE.RS will refer to as the Endurance Training Score (ETS). This model attempts to quantify or scale most forms of rowing training back to on-water rowing in a single scull at a general aerobic heart rate intensity (~stroke rate 20). I originally chose this intensity of on-water rowing as most coaches and athletes I spoke to understood and could relate to this intensity immediately. The model was originally developed by gaining an understanding from rowers and coaches about each of the training modalities that a rower uses and how it equates to on water rowing ie is ergometer rowing harder or easier than on-water rowing? Is indoor cycling harder or easier than on-water rowing? Is indoor cycling harder or easier than outdoor cycling? The process went on and ultimately created an understanding all of these reference points relative to on-water rowing. After that initial scope I began to get a good indication of weighting factors for each of the training modalities that rowers use as outlined in the left hand columns of the table below.

The right hand columns of the table below show how the weighting factors for intensity are used ETS calculation. Time spent in each heart rate (HR) zone is multiplied by the relevant weighting factor and summated to provide an ETS. The coefficients are not based on any scientific evidence and/or physiological data but like Banister base the weighting factors on a typical blood lactate response to incremental exercise.

As training intensity increases the curve linear factor increases exponentially. Simply put the curve linear factor attempts to equate training intensity back to mins of exercise at an equivalent intensity or effort perception of on-water rowing at stroke rate 20. A specific example of this would be that 1 min of Race pace / Over Speed work (Training Zone 6; T6) equates to 9 mins of work at Training Zone 2 (T2) and as such 9 ETS units. The entire spectrum of modalities and training zones are illustrated below but some simple examples would be

  • Examples

  • A single (1) min of on-water rowing at an intensity of Training Zone 2 is equal to a single (1) ETS unit

  • A single (1) min of on-water rowing at an intensity of Training Zone 5 (race pace) is equal to five (5) ETS units

  • A single (1) min of ergometer rowing at an intensity of Training Zone 2 is equal to 1.35 ETS units



Weighting factors both for training intensities as well as Training activities.


One of the real advantages of the ETS unit is it allows coaches to quantitatively compare training programs across training environments as well as allow for flexibility for how an athlete or coach accumulates an endurance training load as dictated by their individual needs. The ETS standardises the wide array of nominal values that coaches have linked to different training modalities i.e. on-water rowing is twice as hard as cycling, ergometer rowing is twice as hard as on-water rowing etc. Importantly, the ETS provides a single number by which the entire weeks training can be judged and compared on.

Understanding the origins and methods of the ETS is the first step in designing and assessing your yearly training plan. It allows you to put a exact number to your light, medium, hard and recovery training weeks and in the coming blogs we will use the ETS to create weekly training load targets as well as individual sessions. However, before we can get to all of this we need to understand how Training Zones are created as this directly affects how much training you must do to reach a certain ETS in each session.


In the next few blogs we will be discussing how to formulate your training zones based on a number of predefined tests as well as some of the limitations of HR based training load estimates and HR training zones

Contact Tony

Feel free to drop Tony an email. Tony is busy, but will reply in due course.

He is available on Tony@rowe.rs

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