Outdoor Vs. Indoor FTP Number

m21519

Question;

    I have always done my FTP tests Indoors, on a trainer.  My current FTP is 234.  In setting my race zone, do I need to account for the "difference" in Indoor vs. Outdoor wattage?  Based upon my Indoor number my (.68-.70) Wattage would be about 160.  Generally, would my outdoor FTP be slightly Higher? Lower?  Can I gain any extra wattage, theoretically?

    Thanks, Mike

jaleslie

Do you have a race coming up soon?  Reason is, many folks have slightly different results from FTP testing indoor vs. outdoor.  

I'm no expert, but from what I've seen from others, and my personal experience, seems most folks usually have a little higher FTP outdoors.  I recall seeing someone post the opposite once, but seems that the majority test a little higher outside.  

For me, that is definitely the case.  I usually can test out ~10-15 watts higher outside.  Furthermore, I think if you test up a gradual hill (if you can find one long enough), it might even be more significant of a difference.  For me, the trainer is just more painful.  No distractions....just me and the lactic acid!  Also, the trainer resistance is so steady, that it is just harder to hold power.  Outside, even though I test on the same relatively flat road every time, there is enough change in grade to require shifting up/down a gear or two, and therefore some variation in intensity, even though I'm trying to push the entire time.  

Just my two cents.....more experienced folks may disagree or have better/alternative explanations.

 

scott dinhofer

Glad you raised this, it is a common topic and I expect Al or Nemo to post us the link to those threads shortly.(I am feeling too lazy to search right now) But some new discussion is always good.



General rule of thumb is to up your outdoors FTP by 10 watts over your indoors.



This raises a question by me to Al and others, do you adjust your FTP in WKO for rides done indoors/outdoors? Or just leave FTP alone at a number for a training cycle between tests?



Also assume you train to the correct NP indoors vs out?



I mostly test outside and then use that same FTP indoors, which suggests I am working too hard indoors? But, I do hold the intervals solid on the number. Whoch to me validates the test. Any thoughts on this?

stevedorris

Mike,

Check this thread for discussion on inside vs outside power. Bottom line...if you experience a significant difference in power inside vs outside, as I do, then test inside and use those numbers when on the trainer and test outside and use those numbers when on the road. Personally, I think its a mental "thing" for me.

http://members.endurancenation.us/Forums/tabid/57/aft/12777/Default.aspx

Keith Wick

You can tackle the WKO in a few different ways. I used to have an indoor me and an outdoor me so I didn't have to swap the number. This negatively impacted my performance management chart unless I then decided to transfer the TSS info etc. by inputting a manual workout into what I considered my main log. However, by keeping them separate it allowed me to have an accurate power chart to use in order to accurately estimate my FTP if I didn't want to test. I find that this mainly impacts my spring when I'm doing an equal combination of indoor and outdoor riding. When I'm in the OS it's inside vs in my IM builds I'm outside so it's really not an issue.

m21519

Yes, my "A" race is here! IMAZ, Just trying to nail everything down. I plan to go conservative, but I would like to know where I stand. My last FTP test, I tested at 246 for my 20' test ( minus 5%) = 234. That puts me at 160 for the IM, but......If traditional thinking is outdoor FTP is slightly higher, I think that would be a mental plus+....

Jenn Edwards

Good question.  Just adding my $0.02 to this thread, apologies for not looking up the older ones….  

 

After four OSs  I’m one of those people who has gotten very good at testing indoors.  Maybe I just don’t have much between the ears and thus don’t struggle mentally.  II do the bulk of my training indoors as well and for the past three IMs (summer) and Lavaman Olympic (March) I would test outdoors shortly before my race. My outdoor FTP has consistently proven to be about 10-15w lower outdoors.   

 

For races I’ve set my targets accordingly with what I consider good results and appropriate fatigue when I got off the bike.  This year, I didn’t make the outdoor test a priority and it didn’t get done.  I used my indoor watts for my race and I think that bit me in the butt a bit (in addition to a major nutrition snafu, but I digress .  Why I didn’t think to adjust my FTP (downwards in my case) after so many tests proving otherwise is an error I’ve certainly learned from.  They’re apples and oranges, IMO.

 

In training because my indoor/outdoor balance is the opposite of Scotts, I don’t hold myself as strictly to my indoor FTP.    My (relatively rare) outdoor rides are typically take-no-prisoners style and not conducive to structured workouts in any case so I’m not much help to his question.   I suspect that if you can hold those numbers inside and aren’t accumulating undue fatigue or otherwise unable to complete the workouts you aren’t doing harm.  I’m sure a WSM will chime in here.   

 

In short, for Mike’s question: I would recommend testing outside within a month or so of your “A” race and using that figure.  That's right around the corner so may not be so helpful now but something to consider... 

 

Looking forward to hearing how it goes!

MattAaronson

@ Scott. Personally I don't bounce around a lot from indoors to outdoors. I'm inside until about April, then outside after that. During that transition period there is a bit of bouncing back-and-forth, and I do a handful of weekday FTP rides on the trainer in-season when I need to do the workout after dark. Usually in the spring on one of my first outdoor rides I replace whatever FTP intervals are prescribed with a 2x20'(2') test. The FTP is a lot higher, doubtless attributable to a combination of outdoor testing AND improvements in fitness since my last test. I then use that FTP going forward for both indoor and outdoor workouts. The indoor ones are a strong minority of the workouts so I think it's good enough compromise and the PMC is only a bit "understated". The amazing thing – and I think this is really important – is that I find in those indoor workouts that although I give myself permission to target the low-end of z4 (95% of FTP) as opposed to the 100% of FTP I usually try to achieve, I can usually hit the new outdoor FTP in my indoor workouts. Maybe it's partly mental because I'm so wired to try and hit 100% of FTP. But in any case it provides an awesome psychological impact and probably some great training benefit as well (if indeed my "true" FTP on the trainer is lower than the outdoor number I'm targeting).