Should I use No Decay after the recent update or not...?

I’m in the UK and well into the start of my out of race season training. If I switch between Optimal Deacy to No Decay since last breakthrough I gain 10 watts… that might well be the difference between training too hard or not being able to complete a workout… given the recent update, help text quoted below… is it better to stay on Optimal or switch?

" Signature decay over time could be prevented by switching to the ‘No Decay – Training Load Matched’ decay setting. However, the latest update to Xert incorporates aspects of the ‘No Decay – Training Load Matched’ method into all other decay settings. What this means is that rather than allowing your signature parameters to continually decay slowly over time from your last Breakthrough, your signature will decay a little, then follow your training loads. This allows the system to more easily detect your next Breakthrough, while simultaneously preventing excessive decay."

I’ve used No Decay in the past for extended periods of Base training when no BT events were likely.
However, with the updated tracking I’ll likely stick with Optimal and see how it goes.
If TP changes much when you adjust decay method, you can experiment by riding an over/under TP workout with the new value and see how it feels.
For example, this modified Dance with the Devil workout.

Reference –
Improvements to Fitness Signature Tracking – Xert (

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For most athletes, the difference of 10W between using Optimal and No Decay likely won’t be a material difference to the training progress on average since there is always some error in both using Optimal and No Decay and that error can possibly overlap the 10W difference you see. If you’re intending on spending a lot of training time at or near TP, No Decay might be the better option but if you’re planning on doing LTP work and mixing in some higher intensity, the difference in the progress you’ll make won’t likely be noticeable. HTH