Recommended workouts XSS way off

I’ve read as many user guides as I can and have a basic understanding, but something is not right.

Yesterday, Xert’s Training Advisor told me to find a **1/2 workout with around 125 XSS. So I chose SMART - Higher Ground - 3.5, which has an XSS of 121. I copied the file over to Zwift and got started.

Xert had me at:
TP - 165W
HIE - 30.4 kj
PP - 1,194W
6min - 263W
LT - 106W

On Zwift I think it has my FTP at 202W or something.

Anyway, did the workout and it comes back at a whopping 351 XSS, not the 121 XSS that the workout mentioned. I had the Xert data screen running on my Garmin (not the workout player, just the data field) and I was at Breakthrough over MPA for almost the entire ride. Afterwards Xert bumped my TP to 182W.

A few thoughts with a question:

  1. My TP seems wrong, 165W was really low, 182W still feels kind of low. I could probably maintain around 210W for an hour if a bear was chasing me.

  2. LTP seems rather low too. If I had to ride a century for example, I’d probably do it around 140-160W.

  3. I’m sure the XSS is way high because those numbers are low on Xert and higher in Zwift, which is controlling the workout, but what workouts should I do to get accurate numbers into Xert? Like how does Xert come up with LTP and TP? I have my resting and max HR set right and have lots of rides for data.

Two things going on as far as I can tell:

  1. Your signature is probably not accurate in Xert. It is determined from breakthrough (all out / to failure) efforts and if you haven’t done that for a while, Xert will underestimate it (also due to signature decay). There are other threads re tips on getting a breakthrough and accurate signature, and I’d do that first (when fairly fresh). It’s purely power based; HR isn’t used for your signature, only for estimating efforts done without a power meter.
  2. You need to set your Zwift FTP equal to the Xert one to get the right intensity in Zwift. As described in the guide, Zwift workouts are defined as % ftp

With a peak power of 1200w I think it highly unlikely your TP is 165w. Not impossible but unlikely
As Wesley says, you need to adjust TP to match FTP or vice-versa.

What was the highest TP you have had in Xert - has decay reduced that because you have not had any breakthroughs?

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Thanks all, I contacted support and the conclusion was exactly as you each said. I also had Strava synching EVERYTHING vs just rides (including my rowing sessions on the water, hikes, bike rides w/o power, etc). I removed all those and am closer now. I don’t want to drop the Zwift FTP to the Xert TP as that will make workouts within Zwift a little too easy, so hopefully I can do a suggested draw-down breakthrough and get Xert in synch. After removing some of the above files it took the latest breakthroughs away, now my last one is four weeks ago.

The highest TP shown in my activities table is 195W. It looks like it gets greatly reduced anytime I do an easier ride, should I flag those rides not to be considered?

What it looks like now:

TP - 190W (still a tad low by maybe 15-20W, but close enough for my fitness level)
HIE - 15.8 kJ (I understand this is work capacity above TP, but don’t know really much beyond that :))
PP - 1,063W (I thought I read in one of the guides this is 3sec power? If so, seems right)
6min power - 233W (seems right)
LTP - 150W (seems about right)

No, it’s actually not reducing due to the ride being easy, it’s just signature decay. If you are only doing base / endurance you can change the decay setting to ‘no decay’… but otherwise leave it… and do a breakthrough effort every now and then (and probably now if it’s been 4 weeks and feels low still)… more detail here: