Which decay setting?

Xata tells me that my last breakthrough was 2 months ago so I’m planning on doing one of the breakthrough workouts on the trainer today. I’ve still to decide which one to try.

My signature has been on “No Decay” for the last two months now.

Should I leave it on no decay and do the breakthrough workout or am I supposed to change it to small decay or optimal decay beforehand?


Think that if you change it, it only applies from today, so shouldn’t make a difference either way to today’s ride. You could go back and change it retrospectively, but wouldn’t bother with that.
If you go all out but don’t quite reach BT (possible as it’s not been decaying), you can always ‘extract’ the signature from the ride, and then save it (in the Advanced MPA tab).

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Many thanks

If you change the decay setting, it’s my understanding that it goes back a recalculates it from either your last breakthrough or your last saved activity. You could try it before the workout to see the effect then change it back again if you wanted. The problem may be that if you have not progressed as much as your signature thinks you have then you may not be able to achieve a BT. Conversely if you change it to Optimal Decay then the BT may be easier to achieve but you’ll have to make sure you don’t stop when you see you’ve got one, but carry as long as you can.

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There is a pinned post in this forum here which explains it… so it applies going forward unless you go back and save / lock a past breakthrough, which forces a recalc from that point on.


Excellent thank you.

No prob - if you’re happy to share, would be interested in how your BT compares to Xert’s prediction. Good luck!

If you’ve ALREADY got a Saved /Locked activity in the past and you do this it goes back to that activity and recalculates you fitness signature,
This this Slow Decay

This after changing to Optimal Decay

And this after changing back to Slow Decay

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Good to know - wasn’t sure if you had go back and unlock / re-lock to force the update.

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