# 4DP test analyzed in Xert **URL:** \ **Category:** Uncategorized\ **Created:** [February 12, 2021, 6:07pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059 "2021-02-12T18:07:11Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Gordo62](https://avatars.discourse-cdn.com/v4/letter/g/9de0a6/32.png) [@Gordo62](https://wahoox.forum.wahoofitness.com/u/Gordo62)\ **Post date:** [February 12, 2021, 6:07pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059/1 "2021-02-12T18:07:11Z")
![Xert The Sufferfest_ # Full Frontal (4DP Test) - Xert](https://us1.discourse-cdn.com/flex020/uploads/thesufferfest/original/2X/b/bdc09daba00a49fddbbc35cb3acf24247bedcbf5.jpeg) ---
**Author:** ![Oliver.Pix](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/oliver.pix/32/178_2.png) [@Oliver.Pix](https://wahoox.forum.wahoofitness.com/u/Oliver.Pix)\ **Post date:** [February 12, 2021, 6:33pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059/2 "2021-02-12T18:33:55Z")
Great effort and a nice breakthrough 🕶 Also the recovery sections with the nearly full restore of MPA demonstrates the valid scientific and physiological modelling in XERT and Sufferfest. ---
**Author:** ![Heretic](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/heretic/32/2329_2.png) [@Heretic](https://wahoox.forum.wahoofitness.com/u/Heretic)\ **Post date:** [February 12, 2021, 6:58pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059/3 "2021-02-12T18:58:47Z")
I do not quite understand, it seems that the MAP effort was a maximal effort, but does not the graph indicate that the FTP could have been higher as there was still MPA left to expend? ---
**Author:** ![Gordo62](https://avatars.discourse-cdn.com/v4/letter/g/9de0a6/32.png) [@Gordo62](https://wahoox.forum.wahoofitness.com/u/Gordo62)\ **Post date:** [February 12, 2021, 7:03pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059/4 "2021-02-12T19:03:36Z")
Theoretically yes the end of the FTP section should be where your MPA touches the power. It would take practice and luck to be able to control your power over 20 minutest to completely deplete your MPA. If you hit the threshold with your MPA 1 minute before the end of the test you would not be able to complete the 20 minutes. ---
**Author:** ![Coach.Mac.C](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/coach.mac.c/32/1214_2.png) [@Coach.Mac.C](https://wahoox.forum.wahoofitness.com/u/Coach.Mac.C)\ **Post date:** [February 12, 2021, 7:13pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059/5 "2021-02-12T19:13:50Z")
This is a copy-paste from a previous response to a very similar question. Theoretically, your 20min test during FF will be equal to your FTP. If your Xert FTP is set correctly, then by definition, your MPA should not drop at all since you are technically never going “above” FTP. In the same sense, if your fitness signature is accurate in Xert, it should very nearly bottom out at the end of the 5-minute effort. If it doesn’t, the most likely culprits are not having your best day on the bike, or your fitness signature has been created around your outdoor power figures, and you will always see some level of decreased power when riding indoors vs. outdoors. Ultimately Xert and the fitness signature are only as good as the data you feed it, and FF results depend significantly on how good/bad a day you are having. ---
**Author:** ![Heretic](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/heretic/32/2329_2.png) [@Heretic](https://wahoox.forum.wahoofitness.com/u/Heretic)\ **Post date:** [February 12, 2021, 7:15pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059/6 "2021-02-12T19:15:37Z")
On another thread , I read that some people use use their bicycle computer to calculate their normalized power during a lap that corresponds to either the MAP or the FF section. That helps them with their pacing. Incidentally, I modeled my last FF before I did it to estimate my output. Here is the model I used: > [@Sufferlandrians using Xert to track fitness?](https://wahoox.forum.wahoofitness.com/t/sufferlandrians-using-xert-to-track-fitness/3702/44): > > There are two parts to the model. The first part is fixed and only has to be done once, the second requires adjustments because your fitness signature changes over time. Fixed Part: Create as many intervals as there are in FF. Each interval is a no-repeat, no rest interval. The length of each interval is the same as in FF. For the two NM intervals I set the power to 100% Peak Power (PP) For the two AC intervals I set the power to the limit of reserve power - 0% Reserve MPA. I initialize all t… Here is where I discuss my results: > [@Sufferlandrians using Xert to track fitness?](https://wahoox.forum.wahoofitness.com/t/sufferlandrians-using-xert-to-track-fitness/3702/50): > > I did FF yesterday using my pacing plan based on my Xert model with mixed results. The plan worked well enough for the NM/MAP part of the test reaching MPA = Power at the end of the MAP segment. I was almost at MPA when the MAP segment started. The NM estimate was pretty close, the MAP was overestimated. The FTP pacing did not work out. There seems to be a relationship between MAP and 20 minute/FTP power that Xert does not capture. I was exhausted after the FTP segment, but the power level was… With the model and a head unit I imagine you could come pretty close. I am going to try that for my next FF. There is also a general discussion about Xert and Suf in that thread that might interest you. ---
**Author:** ![Gordo62](https://avatars.discourse-cdn.com/v4/letter/g/9de0a6/32.png) [@Gordo62](https://wahoox.forum.wahoofitness.com/u/Gordo62)\ **Post date:** [February 12, 2021, 7:21pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059/7 "2021-02-12T19:21:01Z")
Thanks for the information. That makes sense. I haven’t ridden out side for awhile and had been doing mostly sweet spot workouts before trying sufferfest on Wednesday. I think the lack of FTP or above efforts causes my signature in Xert to drop as it was set to normal decay. My calculated FTP in Xert was 248 and my 4DP effort ended up at 265 which is probably why my MPA was dropping for the whole FTP segment. ---
**Author:** ![Oliver.Pix](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/oliver.pix/32/178_2.png) [@Oliver.Pix](https://wahoox.forum.wahoofitness.com/u/Oliver.Pix)\ **Post date:** [February 12, 2021, 7:47pm UTC](https://wahoox.forum.wahoofitness.com/t/4dp-test-analyzed-in-xert/8059/8 "2021-02-12T19:47:42Z")
Perhaps you can adjust your decay setting to “small” in your XERT profile and have a look for your values over the next few weeks. This worked for me, since I don’t “Stravafy” or “Xertify” my commutes. Also after three weeks without breakthroughs my values are nearly spot on, when I finally crush it.