Charlotte Head

23 Jan 2023

Co-creator of ‘sweet-spot training’ aims to simplify training optimisation with his new app, currently used by Human Powered Health

Fastcat Coaching launched Optimize, its new training app, in November last year, calling it the ‘next generation platform for endurance athletes’. The aim of the app is to use the wealth of accumulated data from wearable technology to enhance cyclists’ training and performance.

Not-so-humble beginnings

Fascat was founded by Frank Overton in 2002, who has over 20 years of experience as a cycling coach.

His most notable work includes the creation of ‘training stress scores’ – TSS as they are commonly known – with Dr Andy Coggan in the early 2000s, and ‘sweet spot training’ in 2005.

Fascat now employs nine coaches, many originally coached by Overton himself, and works with athletes in 72 countries.

The team, led by Frank, became the official data analysts for Human Powered Health’s women’s WorldTour team in 2022.

New inspiration

The team at Fascat saw the growing trend in wearable technology as a data goldmine that was largely untapped. ‘The problem is that the data is stuck on those individual platforms,’ says Overton. ‘We want to be the platform that takes the wearable data and the power data and combines it into actionable insights.’

This took shape in the form of the Optimize platform. The app uses several different data points to create an optimisation ‘needle’, which helps users plan their training around their live health data.

‘What the Optimized needle does is it tells users what the balance is between your training and your recovery,’ Overton tells us. ‘This really taps into my fundamental belief that there’s three ways that training can go. I call it the Goldilocks principle: porridge too hot, porridge too cold, or porridge just right. And that’s the way it can go with training, either you do too much, too little, or just the right amount.’

The platform uses heart rate variability – HRV – and sleep data from wearables such as watches or rings, and stress and load from power meters to feed its algorithm. Stress is measured in an evolved form of TSS developed by Overton and Dr Phil Skiba, aptly called ‘optimised training stress’ – OTS.

Better than before

Though Overton’s original stress metric was game-changing at the time, it wasn’t without its flaws. ‘We developed OTS to basically improve on TSS’, he says. ‘The limitations of training stress score were two-fold. Number one, it didn’t take into account physiological changes that occurred during a ride.

‘When you do long rides, say more than two hours, four hours, five hours, the stress towards the end of that ride is much higher than the stress at the beginning and TSS didn’t take that into account.

‘The other thing that TSS did was that it gave you credit for when you’re coasting downhill. If you do 10,000 feet of climbing and you spend 40 minutes descending, you shouldn’t get like TSS credit for those minutes. So, TSS wound up being artificially high, and we corrected that.’

Accurate data, unreliable interpretations

There has been some discourse on the reliability of heart rate variability data since it became mainstream several years ago, with some claiming that the data is an inaccurate way to measure overall health.

‘A single day HRV value does not tell you much,’ Overton concedes, ‘but it’s the trend which is the most powerful way to use HRV data.

‘What we’ve noticed is that just because you wake up with a poor HRV value doesn’t mean you can’t have a great workout or race. And similarly, just because you get like a really high HRV value doesn’t mean you’re magically recovered.

‘The human body is wonderful at adapting to say a poor night’s sleep or a really stressful night and the low HRV is understandable as a one off. It’s not good if that’s consistent over three to seven days which is why we use trends instead of single data points.’

Future plans

Fascat has big plans to expand the platform in the near future, looking to launch the web version of the app in the second half of 2023. While the app is currently only compatible with Garmin, Whoop and Oura wearables, it aims to integrate Apple into its system as well.

It also wants to allow users to be able to deep dive into individual metrics as, at present, the data can only be viewed as a whole via the ‘optimised needle’. There are also plans to introduce a post-workout carbohydrate survey.

Overton’s aim is simple: create a user-friendly system whereby everyone from ‘Tour de France pros to your average Joes’ – to steal his phrase – can get personalised data to help optimise their training.

‘It’s gotten too complicated over the past 20 years and what we want is to emphasise the fundamentals: riding consistently, flexibility and staying with it all year round.’

Looking for more apps to help bring your riding up to scratch? See our guide to the best cycling indoor training apps.

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