Next-gen Coros smartwatch could take on Garmin with smarter fatigue tracking

Coros Vertix 2
The Vertix 2 is one of Coros's most advanced watches (Image credit: Coros)

Coros is working on a new sports watch that will work out how 'fresh' you are more accurately using your heart rate, plus factors like temperature, altitude, and your type of exercise.

A  new patent application published by the US Patents and Trademarks Office explains a new way to calculate fatigue, which will help you plan your workouts and recovery so you can train more effectively.

In the application, Coros describes the problems with measuring fatigue based on perceived exertion alone. "At present, the fatigue degree commonly is assessed by some subjective indicators such as self-feeling, complexion, perspiration, breathing, movement, and expert advice, which often fluctuate greatly due to weather conditions or other reasons, however," it says.

"For example, running at the same pace, a user may feel comfortable if he/she is under a good condition and the weather is suitable, instead the user may feel tired if the weather is muggy and he/she had a bad sleep."

The patent describes a method for calculating chronic training load (the cumulative effect of training on your fitness over time) and acute training load (the short-term fatigue caused by a training session) using a combination of heart rate and recent workout data. 

It will then calculate your 'freshness' by weighing up your fitness and fatigue. The basic idea is that the fitter you are, the less fatigued you will be after a workout.

Smarter training

Most of the best GPS watches use a similar method to calculate fatigue and estimate recovery times after a workout. Current Coros watches already have something similar as part of their Evolab Metrics, which shows the impact of your workouts and suggests the training intensity you should aim for in order to improve your fitness.

Man wearing Coros Vertix 2 watch

Coros is one of few watchmakers that takes climbers into serious consideration (Image credit: Coros)

The method of calculating fatigue described in the patent application is more sophisticated than this, also taking into account factors like temperature and altitude, which can increase stress during a workout,  as well as the type of exercise (Coros gives the examples of running, riding, boxing, and swimming).

Coros makes some of the toughest sports watches for activities like trail running, hiking, and rock climbing (the Vertix 2 can even be attached to a carabiner and clipped onto your harness), so we'll be particularly interested to see whether future devices can take different outdoor adventure sports into consideration. Climbing in particular is underserved by many smartwatches, so more accurate fatigue and recovery figures after you've completed a tough ascent would be particularly welcome.

Cat Ellis

Cat is the editor of Advnture, She’s been a journalist for 15 years, and was fitness and wellbeing editor on TechRadar before joining the Advnture team in 2022. She’s a UK Athletics qualified run leader, and in her spare time enjoys nothing more than lacing up her shoes and hitting the roads and trails (the muddier, the better), usually wearing at least two sports watches.