TTE Question

I really like the TTE\TTR data in short races (ZWIFT). It helps me to decide if I am able to respond to attacks or hill sprints. Unfortunately, it seems useless in longer races (above 1,5 hour) since it does not account for fatique in the sub threshold zone. Riding 1,5h+ in subthreshold / steady state zone (long tempo climb) will certainly empty your glycogen deposit leaving you with fat oxidation only. It is imho unrealistic to assume that my 400W TTE stays exactly the same (approx 5min) at the beginning and the end of such a climb. What do you think?

Absolutely correct! This slow-recovery fatigue as we call it, affects your ability to perform. Your fitness signature represents your best ability and not your ability to perform after hours of riding, just like you wouldn’t do an FTP test after 3 hours on the road. We have plans to provide more info to our users on this in the upcoming releases. Thanks.


Is there any way just now to take into account this slow recovery rate whilst on longer rides so we can make sense of our TTE? Other than going on feel that is! Thanks

Not really… You could use an Xert Code with a different signature, perhaps with lower signature values.

I’ve found this discussion today and seems interesting your answer.
I am in my first week using Xert, after a one-month test a while ago.
This answer is dated from Feb '18, did you managed to develop any tool with the ability to infer about the long-term decrease in performance? Currently, I am doing Zwift races (Classics and TTTs) and TTE/TTR looks fine, but I have some 2 to 4 h road races (IRL) with stages in my objectives for the end of this year.

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Hi Alvaro,

Thanks for joining Xert.

Long term fatigue is multi-faceted and would be difficult to predict how much power you have accurately since the inputs needed like how much food you had and when, hydration status, outdoor temperature and even things like the amount of sleep you had all can play role in limiting your ability to reach your best after hours of riding.

What we can say though is that gaining a perspective on how well you can perform relative to your best ability is useful in understanding of how well you’re managing the above contributors to fatigue. For example if you fuel well (have enough carbs), manage your intensity and stay hydrated, you’re in a much better position to breakthrough deep into a ride. If you can get a breakthrough after a few hours is an indicator that you have managed your carb intake and intensity well from the beginning.

Hope this helps.

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Great explanation. I got it. Thank you.

I think there is another option you may not be considering and that is the power curve vs time. My power curve extends out for over 19 hours. This can predict the decline in maximum and threshold efforts and I bet it can help predict recovery times. I ride double centuries (200 miles) regularly and managing energy resources is very important. Exceeding LTP comes with a cumulative cost. Understanding how much and for how long I can go above LTP Then time to recover would help me improve my finishing times. I can understand why this functionality may not be a priority but it would be helpful for century and endurance riders to optimize long efforts