Avoiding Spiral of death

I’m a new user to XERT workouts but an experienced cyclist outdoors, Zwift, Sufferfest, etc. I’m using Stages SB20 using Auto for XERT workouts.

Did my first workout Sunday and it was brutal. I learned that the resistance for intervals doesn’t change until a second or two after the interval ends. With this in mind I did my second workout. The first few went just as expected then I got to an ntermediate section and I think I let my wattage drop too far and I entered the spiral of death which I could not get out of despite several pauses. I also noticed cadence needed for work intervals is extremely high.

Would ERG mode be better? Perhaps this is just an adjustment period.

Thank you in advance.

Hi @Pschack , welcome to Xert!

Which workout(s) were you doing? Most trainers take a few seconds to reach the target power for an interval & then also take a few seconds to drop the resistance at the end of an interval. The lag on the front + back end usually ends up evening things out. In my experience, the delay/lag (with Xert & other apps) can be more extreme when going from relatively low power to relatively high power outputs, like 100 W to 350 W, for example.

Best practice is to start spinning up a few seconds before a hard interval starts & hold your cadence at the end until you feel the trainer drop the resistance.

Is there a way out of the spiral of death once you’ve in it?

Perhaps someone with an SB20 will chime in but many trainers allow you to backpedal to lower watts then spin up rapidly to jump back into a tough interval.
If problem persists, you could switch to Slope mode and hit targets using gears/cadence.

Speaking of cadence, something else to try is run EBC in conjunction with the Remote or Session Player on PC/laptop to monitor the CO gauge (Cadence Optimizer) in upper right of rainbow gauge.


This displays your preferred cadence at torque. For example, with a red interval coming up the CO will change during the transition beeps and display your preferred cadence highlighted in blue. Spin up to that target range right before the interval hits. For example, you may be spinning 80-85 rpm during a RIB (rest-in-between) interval. However, the upcoming interval requires 110-120 rpm.
I rely on this feature for many HIIT workouts. I glance at the CO after the first transition beep then rev up to that range before the tough interval starts.

I was doing two AI workouts. Yesterday was a smart workout. High power sprints for 30 seconds a piece.

SMART workouts can include intervals that monitor your compliance to target and increase or decrease resistance accordingly. You may, for example, feel an extra push at the end of an interval to ensure the intended strain was reached.
Depending on trainer responsiveness there can also be a lag between transitions so you may need to ride past the interval block before your trainer settles into rest interval watts.

Some sprint workouts will change to Slope mode before the interval. This is a function of EBC when running in AUTO mode. SMART - Adventures of a Lifetime is an example.
In that case you want to determine which gear/cadence is best suited to the upcoming effort which you can dial in during the first interval in slope mode.

I think I’ll try slope mode tonight. With the large flywheel it might be best, 50 pounds with the short intervals.

Using Slope mode worked like a charm!

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