By how much should I reduce the target power for indoors workouts?

In addition to ventilation (and hydration which Armando mentioned, but doesn’t seem to have generated much discussion), a couple of other factors come to mind - not sure how strongly each is proven though:

  • what position are you in for outdoor rides vs indoor e.g. were your steady outdoor efforts on climbs vs indoor on flat? Would expect different mechanics and efficiency due to different alignment with gravity / position relative to BB, hip angle etc. That can also affect breathing.
  • How stable is your core when pedaling? or how much do you move your bike under you when riding outdoors, even seated? indoors the bike won’t move which again changes the pedal stroke… you may be unconsciously shifting your whole body side to side (slightly) each stroke, which would take more energy for example
  • What gear ratio are you using on the trainer? read an interesting article about the impact of kinetic energy on power output and perceived difficulty (explaining why some people can put out more power climbing but struggle on the flats, irrespective of cadence) so wonder if speed of the flywheel could have an impact? you can google climbing vs time trialing cycling tips… and of course can experiment at home in ERG mode with high and low gears
  • Are results different for ERG vs slope mode - again thinking of changes in pedal stroke due to difference changes in required torque and power throughout the stroke with each option

Indoors, depending on the type of workouts I will do, I select a road on BigRingVR to make it compatible will the efforts I will have to produce. For ex., if I have to do a 3x13min. Ronnestad, I select a road will some gradient to do the intense intervals with a “reasonable” cadence, but not too hard, so that the slope doesn’t impact the recovery intervals. One good thing with BigRingVR is that you can also limit the min. and max. gradient (between -25 and +25%); so if required, I will limit the slope to 3-4-5% for some efforts, and the downhills to … 0%, so I won’t do high cadence to reach a target power.
Previously I had a Saris Hammer 3, and the reported power was different between the small and the big ring : 5-10% too generous on the big ring. So, I was doing most of my workouts in ERG mode on the small ring. I don’t have that problem anymore with the Direto XR.
As I’m doing most of my workouts with BigRingVR to ride great virtual roads, when I’m not in ERG mode, I follow the profile, so I change my gears as I would do outdoors.

OK, so your 3x20m vs 3x15m indoor vs outdoor were on similar simulated slopes(?), but in practice the outdoor one was on a real incline, while indoors you are level? you could try putting a few books under your front wheel to make it more directly comparable?

Yes, the 3x15 outdoors was done along the local river, so mostly on a flat road. The 3x20 indoors was on a slightly wavy profile: 700m of elevation on a 50km ride; I think I also limited the percentage to a max of 4% ? And if you look at the screen captures, you’ll see that my cadence didn’t change during the incline variations, going up or down, it remains the same, as well as my HR: stable during each interval.
BTW, you will see that shows a parameter, the ratio Power/HR, that is much lower for the indoors workout vs outdoors (1.35 vs 1.46: the higher, the better !). And you’ll see that my cadence was lower when outdoors, probably because, from my perception, it was way easier. I mean, outdoors it was an “easy ride”, I set the RPE to 4 only because it was turning kinda “boring” during the last 30min, else I would have it set to 3. But for the indoors one, it was kinda challenging, so, a good RPE 5…

PS: anyway… I will also switch the PM from my 2 bikes, to check if some discrepancy appeared since… last year, I think ? Just to be sure…

That’s another biggy. Get it singing in a big gear like a 53 x 12 and use the ergometer function to dictate the power level.

Hi there all. I’m new to the program so bear with me if this has been discussed or handled elsewhere.

Most of the suggested workouts are quite long, in excess of 1h.
I find myself having a hard time spending above 1h in the indoor saddle (can stretch it to 1,5 h) while outdoors I can be in the saddle hours after hours.
Firstly- am I alone on this or ?
Secondly - if this is a common issue, the suggested workouts are to my liking a bit too long. Yes, I can quite halfway - but then I miss the point of concluding the workout. Hate to quit and suggest a bit shorter (more mentally appetizing) instead of one quitting after an hour or so. I guess the plan needs to be addressed and altered due to the lack of XSS.
thx P

Welcome aboard. I suggest you start with this thread which includes many newbie tips –
Beginner questions - Support - Xert Community Forum (

User Filter to the right of Recommended Workouts to change duration and select a shorter workout. For example, 30 minutes to 1 hour 15 minutes, Apply Filters. then Load More to view all twenty possibilities.

Let Xert get to know you over a few weeks. You control hours/day and which days to train and rest. XATA will recognize any pattern you establish and begin to say “Advice is based on your recent activities performed on < day of the week >”. That doesn’t mean you can’t change the pattern whenever you want but indicates what you have been doing.
The pacer needle position is more important than daily XSS targets which will vary over the week depending on your schedule and commitment level.

Riding indoors does take some getting used to so by all means lower the minutes and build up your capacity over time. Rising out of the saddle for some intervals and changing positions will help alleviate indoor-itis. :slight_smile:
If necessary lower IR to reduce how quickly you will ramp up. Any change will be noted by the pacer needle and hours/week slider in the ATP box.

Improvement Rate (IR) sets the tone for how many hours per week you will train starting now and moving forward. The higher the rate the more hours/week are required and intensity are required over meet the projected XSS goals. You will also use IR to reduce hours (Taper) or when taking time off (Off-Season setting).

Reference –
Beginner’s Guide: Improvement Rate – Xert (

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Totally off topic. How do you get all the workouts to Intervals calendar?
Do you export them from Xert one by one and import them?

Yes I do export them, one by one, in the ZWO format (though I think that the other formats should work). And import them from After some time, most of your regular workouts have been adding to the library, so it’s becoming easy to add them to your calendar…

OK, folks… MY BAD !!!

I swapped my PMs and found out that the one I use for my workouts outdoors, returns at least 10% more watts than my HT and the other PM I have which was calibrated to match the one from the HT !

So, today, I was able to do my indoor workout with an HR close to the one I had outdoors. Feeling fine after 3 hours of “Take me to the church” :smiley:


I have the same set up as you but I have the Vacmaster on third speed all the time, lowest speed does nothing. Try turning it up to full speed.

How do you position it ? Mine was positioned “full front”, almost against the front wheel, on a 40-50cm furniture, and oriented at 45°. Lately I put it directly on the floor, on my right at 2h (or left/10h if you prefer), it gives me a slight breeze on the legs, in addition to the torso. It helps me dry my back, but I still finished my last 3h workout, drenched.

I have it alongside my front wheel at about 10h, on the floor and angled so that it is on my chest not my legs at all. It is always on full speed but if it is a bit cold at first I might leave it off and then turn it on with a smart plug. I never do anything like 3 hours on the turbo though !

Glad to see you resolved your watts/HR disparity but if you’re still drenched after most workouts the ventilation issue remains.
Lasko/Vacmaster Air Movers push lots of air but with a focused flow unlike outdoors where your entire body is enveloped in a breeze.
Consider an industrial-style fan if you have the floor space, or dual fans for more coverage, or try moving the Vacmaster further away at a higher speed.
I’d also nix the jersey/shirt indoors. Even bib shorts are too much for me when riding indoors. Evaporative cooling works better with skin exposed. YMMV :wink:

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+1 to the above.

TMI :see_no_evil:

I use two Vacmasters, one aimed at head, one at body. I have them plugged into a device that allows me to switch them on remotely, once I have warmed up. I think I spent $10 on the switch, with remote control.

How loud are these things out of interest? For sure fine in a garage or basement, but anyone using them in an apartment? Early morning before the family or neighbors are up…? Quiet and powerful would be great, but not sure it exists?

I don’t think they are unusually loud. I watch movies etc on my iPad.

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I use one in my apartment in the room right next to were my girlfriend and our 6 months old sleep.

It’s a laudish humming sound. You can hear it in the other room but it’s not loud/strident to wake them up. Equivalent of being in an airplane.

I put my headphones and barely notice it.

But I guess it depends how light sleepers the rest of your household are.

There is a version with a remote control that I recommend.


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