TrainingPeaks – how much do you know?

Most people these days are using some kind of tool to track and plan their training. One of the most popular choices and what we use at Felix English Coaching is TrainingPeaks. But how many of the key terms used on the software do you fully understand the meaning of? This short article aims to give a quick summary of the key units used on TrainingPeaks to help you better understand your own training.





Training Stress Score – TSS


Training stress score is probably the most widely used unit on TrainingPeaks. It gives an approximate guide to training load for each session and can also be used to assess fatigue/recovery time needed after a session or competition. It’s calculated using the Intensity Factor (IF) and duration of the session. Although every rider differs on the workload they’re able to tolerate, the below figures give a rough estimate on recovery time compared to TSS.

Tracking TSS over long periods also allows you to estimate the amount of duration and intensity needed in order to see performance gains without overtraining.


TSS less than 150 – can normally train the following day with recovery process completed

TSS between 150-300 – residual fatigue still normally present the day post session but should be gone by the next day





Intensity Factor – IF

Intensity Factor is a relatively simple term – it is a calculation done on TrainingPeaks that does exactly as it sounds, works out the intensity of each individual session. It does this by comparing your Normalised Power and your Threshold Power. For example, if you had a threshold power of 300w and you had a normalised power of 300w for 1 hour you would have an intensity factor of 1.0. This TrainingPeaks unit is particularly useful for identifying if a riders FTP has changed. As an example, if a rider has completed an hour long event with an Intensity Factor of more than 1.0, it indicates that their threshold value has increased.




Fatigue – ATL

Fatigue is calculated from an exponentially weighted average of your last 7 days of training TSS scores.




Fitness – CTL

Fitness or CTL is an exponentially weighted average of your last 42 days of training and each days TSS and directly reflects your last 6 weeks training. However, the most recent training sessions will have a higher impact on CTL than older sessions.




Form – TSB

Form is calculated by subtracting yesterdays Fitness (CTL) against yesterdays Fatigue (ATL). This number offers up the chance to see the balance of training stress and a positive number during competition usually indicated to being fit and fresh.




Normalised Power – NP

Normalised Power is a tool used by coaches to quickly see a more realistic power average from training sessions that don’t have a constant power. For example, a criterium or a circuit with multiple short climbs/descents will often result in a lower average power due to the frequent ‘soft-pedalling’ or freewheeling. NP calculates the approximate power you could’ve sustained for the same duration of time, using the same physiological effort if power had been consistent.




Was this post useful? Would you like to know more? Let us know your thoughts at felixenglishcoaching@gmail.com

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