Today I did sprint all-out, the Xert-plugin in Garmin announced an breakthrough and I felt that it was my best sprint-affort so far. It was 1220 watt, as shown in Xert:
But still: no update in the signature, still 1152 watt and suddenly no breakthrough, even when the Xert-plugin announced an bronze-BT. If the reason is, that I have to hold the PP 5sec … than it is not the real PP but the 5-sec-max. But even then the Xert-plugin should not show an BT. Did I miss something here?
XO (xertonline) operates at a higher level than the apps (Garmin IQ player or EBC phone app).
If it was a short spike, it did not fit the algorithm profile required to calculate a change to PP.
Well… I did hear the BT-Sound on my garmin. But ok, it was a mistake than? That should be fixed, if possible. So when the max power output (1 sec) even in Xert is like 1219 (and garmin connect agrees) but the signature stays at 1151 – 6 % difference – what does PP in Xert actually mean? Is it the 3-sec-max-power or what exactly?
Not a mistake. Simply due to the difference in precision between the apps and what the server can do with the data including your historical figures.
All of the signature numbers are derived.
PP is the highest possible power duration Xert predicts you are capable of, not the highest power measured by your power meter.
You will see this in action when you experience a change in PP during a BT workout where you expressed your fitness under fatigue at power numbers well below your max.
You should also think of your TP as an estimated value. For example, 210-ish or 220-ish, not 211 or 218. It is never really an exact number and is subject to change day to day.
Consider power meters aren’t precise and vary depending on brand/model accuracy (1-3%).
Spikes can also occur while riding which is something XO attempts to strip out when uploaded data is analyzed.
On occasion you may have screwy power data from an activity affecting your signature. You can manually flag that activity to remove it from sig calculations while the averaged strain score counts for TL purposes.
On a related note, don’t be upset when you experience a Near BT (fake through) and a slight decline in numbers. It means you were very close to what Xert expects your signature to be. A validation moment so to speak. If you prove otherwise on subsequent activities the numbers will rise again.
For training purposes, you only need your signature to be in the right ballpark then move forward from there. Enjoy the ride.
