Endurance Skating

Training, Racing & LCHF Fueling For Skating And Endurance Sports

SportTracks & Training Load

Training builds a long term adaptation to the work – which we call fitness – but it also makes you tired in the short term. Upon these truisms are built the many “similar but different” theories of training which are understood and exploited by all athletes today.

Training Stress Score (TSS), as I have previously written about in my synopsys of Joe Friel’s Cyclists’ Training Bible, is one of the more sophisticated and widely used models of training and performance that has a track record of producing positive results.

Modelling Training & Fitness

Broadly speaking, TSS = Time x Intensity (plus some smoothing mathematical algorithms applied). Simple enough, right?


“When I said I wanted a fitness model…”

One of the key benefits of TSS is that it converts all modalities of training into a common currency – every activity from swimming, running, skating, or weights, and whether you are going by pace, heart rate, or power – is converted into a simple numerical TSS number.

From the accumulation of TSS from each individual workout, we can chart our Acute Training Load (ACL, ie Fatigue), Chronic Training Load (CTL, ie Fitness), and Training Stress Balance (TSB, ie the difference between ACL & CTL, ie ability to race, aka form).

Yes, this can all be very confusing if you are unfamiliar with this model, but it has been around for a long time now and is widely used by coaches and athletes – especially multi-sport athletes (hence it’s popularity with Triathlon) for whom the conversion to a common unit of training (TSS) is helpful in evaluating the effect of training in multiple disciplines.

Competing Platforms

Many platforms such as Strava and Garmin Connect will rate the intensity of a particular workout using their own algorithms (for example, Strava bike workouts will calculate a “Training Load” and “Suffer Score” if you supply the necessary metrics and set it all up correctly), but most of them do not really provide the capacity to further analyse the cumulative effect of multiple training sessions or provide the tools to assess and track fitness and performance over a period of time.

And with good reason – they aren’t really meant to be serious analytical platforms. That is the realm of Training Peaks and other such dedicated software. While most serious athletes are most familiar with the Training Peaks platform to monitor and track their training, there is at least one other very good alternative that I have personally begun playing with:


This platform from https://www.zonefivesoftware.com/ comes in a couple of variants:

  • SportTracks v3/Pro – Traditional Windows standalone App
  • SportTracks Mobi – Online only Webapp

The SportTracks v3.1 client


SportTracks Mobi platform

The convenience of the SportTracks Mobi Webapp version means that you can manage your workouts anywhere from your mobile phone. However, my personal preference is for the Pro (Windows) version, which is more feature-laden and flexible at this point in time. Importantly, although they are 2 standalone platforms, there is a “CloudSync” feature which allows you to sync the Windows App and the Online app.

Essentially, a vanilla version of SportTracks acts as a Training Logbook – you record all your workouts into the Activity Log as a database of your training history. This can either be done manually, from a GPX/TCX etc file, or (most easily), directly from your sportswatch device – most popular brands are directly supported.

Also, similar to Strava, the WebApp platform is also sync-able with your Garmin Connect account. Cross-platform transfers are becoming increasingly available, with many main sports tracking apps of this nature, so we will be seeing much more of this from all the major players in the very near future.

All said, the onerous task of entering your workouts is made as painless as possible. And one of the best things about the Mobi platform is that it has “Skating” as one of the main workout categories – Hooray!

Once you have the raw data in as best you can, you can slice and dice it, unleashing the power of the platform and analyse your training at a much more advanced level than previously…

PlugIns | Training-Load

Having a fancy training log is all very well and good, but the real beauty and power of SportTracks is the open API they have written so that 3rd-party boffs can write their own plugins for the platform. This is a huge differentiator to the closed-platform feel of Training Peaks, and means the application is much more community-driven. All of the plugins are useful to some degree, and many will help you to visualise your training in very novel ways.

One of the best plugins for SportTracks, and the one that got me immediately interested in the platform is the Training Load plugin.  This essentially takes the data from the your Training log and then calculates the TSS/ACL/CTL & TSB values which hopefully you will have a firm grasp of if you’ve been taking notes so far 🙂

From my understanding SportTracks uses TRIMPs (Training Impulse) rather than TSS (which is apparently a trademarked acronym) but the principle is exactly the same – to quantify the training effort.

Training Load is just one of the 90-odd super useful plugins that have been written for the SportTracks app, and it absolutely does what it says on the tin enabling you to chart your fitness and training similar to the tools available in the Training Peaks Performance Management Chart (PMC).

Another useful plugin is the Race Performance Predictor, which is like an advanced VDOT chart and will give you race performance predictors based on your performance at another distance, and which you can also enter different weather conditions, racing weight etc to see how it will affect your performance, as well as use slightly different extrapolation models.

Anyway, the Training Load feature is available at an Plugin on SportTracks 3, and has also quite recently also been integrated into the SportTracks.mobi platform. On the mobi platform, the TRIMP score is simply called “Effort” to give the whole thing an idiot-appeasing feel. Both versions will calculate your Fitness, Fatigue & Form, but I personally much prefer the v3 Plugin, as it is is more feature-laden and configurable.

Training Load In Use

Let’s take a look how the Training Load plugin can be used to track and assess my training as I start my annual winter training in the buildup to my first main race of 2016 (the Barcelona marathon on March 13th).

Training Load 2016-01-14aOn the first view we can see the Daily TRIMP calculated for each day based on all the total of any workouts done on that day. Where there are gaps indicates a day that I have taken as a complete rest day.

Training Load 2016-01-14bHere I have added the ACL (Fatigue) line, calcuated as the Daily TRIMP’s 11-period moving average and the CTL (Fitness) line calculated as the Daily TRIMP’s 45 -period moving average. You can see that Fatigue (ACL) is far more responsive to training than Fitness (CTL) and climbs at a faster rate, but falls more after a rest day.

Training Load 2016-01-14cNow I have added the Training Stress Balance TSB (Form), which is simply the CTL – ACL. I have removed the daily TRIMP bars to declutter the view.

Training Load 2016-01-14dFinally, I have added the Training Influence curve – this is linked to your Race target date and gives you an idea of how much “bang for the buck” you will get for training during the weeks leading up to your target date, and therefore when your training should be peaking.

A 1hr workout when your Training Influence is 0.4 will have exactly the the same impact on your race performance as a 2hr workout when your Training Influence is 0.2.  Let me say that I absolutely freakin’ LOVE this feature – it perfectly illustrates the importance of understanding the theory of training, and how to maximize your return on investment.  Note that close as you approach race day the Training Influence curve quickly turns down and then deeply negative – as I’ve written about, hard workouts in the last 11-12 days before a race are almost certain to be negative to your race performance as you will not be able to shed the fatigue accumulated from such a session – Training harder when it matters the most!!

Some of these numbers might flummox you if you are unfamiliar with the maths behind them – eg why is ACL an 11-day average, and CTL a 45-day average? Suffice to say that most of them are set to industry standards, but if you don’t agree with them you can tinker with them. On the whole though, I don’t touch them, and neither should you, unless you have a very good grasp of the maths behind it all! 

It’s important to point out that, with all the quantification and number crunching, this is still a very imprecise science. A precise performance score does not correlate to a particular time or performance level (if only it were that simple!), it just means that, in theory, you are better trained and race-ready than if your score was lower.

The crucial point when using Training Load (whether you are using SportTracks, Training Peaks or any other platform) is that you must ensure that your training log is as complete & accurate as possible. Missing workouts, or over/underestimating your heart-rate or duration of your workouts and you can end up with unrepresentative TRIMP & TSB scores. Garbage in, garbage out.

This is the most painful part of the setup – ensuring that you enter a decent history of all your training upon initial setup. It took me a couple of hours to fully enter my 7 week training log, but then seeing the payoff was well worth the time.

It is possible (and encouraged) that you pencil in future planned training sessions to see how the shape of your ACL/CTL/TSB will look going forward.

Personal Opinion – Is it as good as Training Peaks?

Whether or not you prefer Training Peaks or SportTracks is very much a question of taste. I can honestly say that my brief dabbles in TP have always left me frustrated and confused, while I had a much easier time with SportTracks.  Now, having been using SportTracks, I cannot see a reason why I would want to switch to Training Peaks.

SportTracks is also cheaper than TP, although not free – and it shouldn’t be free, it’s a fantastically powerful piece of software that can give you key insight into your own training that could reap far greater rewards than that spending money on upgrading kit or supplements could ever hope to provide. Properly used, it can be a difference maker.

Model Limitations & Warnings

However, a word of warning. There is a saying that “all models are wrong, but some are useful.” This model of performance has clear limitations and is clearly “wrong” on some levels. By far the biggest thing to be aware of is that Training Stress takes no consideration of the distribution of intensity of training that you have been doing.

15 minutes of threshold work produce the same TRIMP score as 30 minutes of base work, but there is clearly a right and a wrong time to do either and race day performance will depend upon getting the right type of training done at the right phase of the training plan. A higher TRIMP does not necessarily mean that you body has absorbed all that training. 

There is also the issue of how to fairly represent gym & strength workouts in terms of TSS. The TSS calculation is clearly driven by cardiovascular output, so falls short in terms of how to quantify training stress that is strength-based.

Therefore, in my opinion, Training Load is most useful as a supplementary tool to tweak and fine-tune an well designed training plan and not as a wholesale substitute, and it is certainly not an excuse to fly by the seat of your pants each day without a long term plan in place.


Is Training Peaks/SportTracks necessary at all?

No, of course it isn’t. There are plenty of successful athletes who do just fine and make progress year upon year using far much less sophisticated.

However, I do firmly believe that if you are at all serious about training then at least some form of training log is essential, whether it is a spreadsheet, a written logbook or some other system you use. There are no serious athletes whose training plan is all stored in their head.. keeping a log is absolutely essential – you will not find a coach on the planet who says that you can wing it.

So given that some form of record keeping is essential, you may as well go to the trouble to do it with the same effort as you put into the rest of your training and take advantage of something that will record and calculate totals, and provide you with further analysis to your help you get the most out of training.

I have used a GoogleDocs spreadsheet for the last couple of years which has served me very well, and at the moment I’m having a sentimental problem abandoning it and jumping ship to SportTracks. However, the more I use it this platform, the more I’m liking it. That’s normally a great sign, so I’m going to use it for this training cycle to see how I get on… I expect that I’ll be absolutely swearing by it before long.


Some other blogs:


2 comments on “SportTracks & Training Load

  1. Van
    January 18, 2016

    Joe Friel’s 3-part series on Chronic Training Load is a great read to further understand these tools:


  2. Pingback: Winter Marathon Training | Endurance Skating

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This entry was posted on January 15, 2016 by in Equipment, Resource, Science, Training and tagged , , , .

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