Indoor vs outdoor training FTP values
 

I started my winter training about 2 months ago, mostly indoors, and noticed that my indoor FTP was about 20 watts lower than my outdoor FTP (245W indoors vs. 265W outdoors, measured on the same power meter).

As such, I lowered the FTP setting for my indoor workouts (Zwift workout mode) accordingly -- using the outdoor FTP would make it impossible to complete.

Now on Training Peaks, all my indoor training result in lower IF and TSS values, making it appear as if I'm under-training. I try to include both indoor and outdoor rides throughout the winter season, so I can't simply change my FTP to my indoor FTP.

Has anyone else run into this problem? If so, it'd be awesome if you can share ideas/solutions.

Outdoor FTP from recently, or from months ago?

If you've been doing this for 2mo, using your outdoor FTP, how do you feel relative to your current CTL/ATL/TSB metrics?

I'd leave the FTP alone and just scale your indoor efforts back and accept that you're likely under-training to your true capabilities. I haven't found exercising in the garage suddenly changes my bodies power or ability to absorb the training loads, and its just the environment that makes the indoor 1.0 IF feel harder than the outdoor 1.0 IF.

And I imagine it's a bit of a feedback loop ... if you train with less intensity indoors, your power will eventually decrease, leading you to lower the intensity even further.

You can edit the TSS manually, if that is a metric you care for. Whether it is a good or bad idea, I do not know. I don't really use TSS for planning my training.

I'm not sure it's a problem. It's just the way it is. For almost everyone, under test conditions, power output is higher outdoors. My "solution" to the issue has been to ignore it. It doesn't matter that much to me because, during "trainer" season, I'm not fixated on IF or TSS. This is primarily because I'm in Base Phase training and what interval work I'm doing, I'm generally able to do outdoors. My indoors miles tend to be Zone 2 (with brief forays into other Zones). And Zone 2 is easy enough and broad enough to offer a lot of leeway.

I never change to an indoor FTP. I test my FTP outdoors, over the same course, every time. And I leave the current FTP in my software whether the ride is indoors or outdoors. And, for indoor rides, I accept workout power values in the lower half of the range the workout calls for. Outdoors, I try to hit the mid number or higher, within the range.

The outdoor FTP mentioned above is from 2 months ago, but it is likely higher now. Although I haven't done a proper FTP test since then, I have continued to ride outdoors, and my average power is consistently higher vs. indoor rides (can hold 300W for 10 min just fine, but I would really struggle to hold that for 5 min indoors).

My legs feel like jelly after some of the hard sessions (VO2Max 5x5, long FTP intervals, etc.), but I'd only end up with 0.8 IF or lower, which doesn't seem representative of the effort...

Yeah, I'll probably leave the FTP setting as is. I don't think I'm training at a lower intensity indoors though. I read a few articles which state that it is common for some riders to have a lower FTP indoors, while others have nearly the same value. When I ride outdoors with others who are also training indoors, I keep up and even overtake some of them on full effort climbs (their indoor FTP is the same as outdoor FTP).

I thought about recalculating TSS using my indoor FTP.. but I was also unsure if this was a good/bad idea..

I suppose you're right about not getting overly obsessed about IF and TSS.

Based on a Training Peaks article, it recommended targeting a TSB range of -20 to -10 for 'effective training' (staying in a range of -10 to +10 for prolonged periods was considered to being 'stagnant'). The optimum range wouldn't be feasible for me to maintain if I used my outdoor FTP for indoor training. Some annual training plans also provide weekly TSS targets.. those would also be hard to reach under this circumstance (unless I ride the trainer 15+ hours/week!).

It'd be nice to see my training progress and track CTL, TSB, etc. accurately though, since that's the main purpose of subscribing to Training Peaks, WKO, etc.

Working to stay in that TSB range depends on your goal. That range pops your CTL up very quickly. Do you know what CTL you can sustain for a couple weeks or so before going over the edge? What CTL are you heading for and when do you want to get there? I always use the Dashboard view that shows a chunk of the future. I'll plan workouts to move my CTL in the direction I want it to go and at the pace I want it to go. Then I do the workouts or try to and see if my guesses at my capacity were correct. It's no good working your butt off to peak in March unless you have big event in March. My first training target is a bike tour at the end of April, so I plan my CTL to go through a couple of sawtooth jumps before arriving at my best guess at a good CTL to have at this time of year when starting a week's bike tour.

I'm saying "stagnant" isn't necessarily a bad thing. I might do a couple of months of base when my CTL might only increase by 5 per month if I were in decent condition when I started that cycle.

The highest CTL I maintained was around high 80s, which was in the summer when I rode 4 days a week outdoors (300-350km). Its dropped to and being maintained at low 70s now, due to taking it easy for a couple of weeks in the fall coupled with lower TSS from indoor training.

I don't have a target CTL or a specific period I want to peak at in mind, but do have a series of races starting this month until end of October (of equal importance). Is it not ideal to try to be in optimum fitness throughout that time?

I'm not highly knowledgeable in terms of optimizing my training, and my use of Training Peaks up till now has been limited to tracking CTL/TSB trends and power profile. Its just that these values haven't been reflecting my training efforts recently since I started training indoors, and I wasn't sure if I needed to do something to make it more accurate.

No, you don't need to do something to make it more accurate. It's not that accurate anyway because it doesn't take into account other variable aspects of your life, like rest and stress etc. Just mentally keep track of this and be aware your CTL is a little underestimating things during times of indoor training.

What kind of racing are you doing? No way can you be in top form from Feb til October. You can have one or two peaks during that time, maybe three. But it will be a huge training mistake to try to be in top racing shape in Feb and maintain that until October. You are going to have to prioritize your races. Pick one or two that you want to win and train to be in top form for those.

Yep, not possible to be in peak form for months on end. You can be in good shape for that long, but not in your BEST shape. This is why the software is called "Training PEAKS." You want your fitness and form to PEAK at two or maybe three (or maybe one) times of the year. The whole idea of the peak is that you reach a pinnacle of fitness that is not possible for your body to sustain long term.

Most of my races will NOT be when I'm at my peak. I select a couple races per year -- one in Spring, one in Fall, 3 months apart -- when I plan to peak. I expect those peaks to last a couple weeks each. After those peaks, I expect and plan for my CTL to drop. It has to drop so that I can recover and begin the process of building to the next peak. During my strength training phase (generally mid-October thru mid-December) my CTL drops even more as I spend more time in the weight room and less time on the bike. Then, in Base Phase (starting mid-December), I begin the process of building fitness back for the next Spring's "A" priority race. That's why I don't worry so much about precise indoor trainer TSS/IF numbers. I know from experience that I'm headed in the right direction and I still conduct my every-six-weeks outdoor FTP test to see how it's going.

This thread is covering some of the same ground as the "Why is more training better?" thread: http://www.bikeforums.net/training-n...ng-better.html

There's an element missing from both threads: how do you know that you've peaked given your current ability to absorb training? Or put another way, how much training can you absorb or how high can you hold a CTL? How do you know your limit before you go over the edge? Because the price of trying for too high a peak or for holding a peak too long is overtraining, which will put your training into a big hole pronto, and which is very hard to climb back out of.

I have a couple ways: Can I hit or hold a certain HR or gear and cadence (I don't have a PM) on a familiar climb? Not being able to hit my numbers means take it easy or time off. I also chart my morning resting and orthostatic HRs. Persistent high values on either of these, especially the orthostatic, is a warning sign. I move the CTL up until I see warnings.

What do you do?

I do two things: First, I always have my HR Zone displayed just beneath my Power Zone on my Garmin. Between FTP Tests, I know that my HR should be trending less and less for a given Power Output (or power increasing for a given HR), until the zones are recalibrated at the next FTP test. If I see an interruption in that trend, I know to look for issues. Short-term, it may just be that I'm dehydrated on that workout. If it persists into the longer term, I probably need an extra recovery day (or two or five).

Second, this is where my every-six-weeks FTP tests come in. If my training is progressing well, I should see a positive trend from one FTP to the next. If my FTP plateaus, I know to look for the cause. My training isn't working for some reason. If my FTP drops and there's no other clear reason for the drop, I know that I probably need to adjust my training for more recovery between workouts. (I've had this experience before. My training was going great so I increased my 3-week training cycle to a 4-week. Even though I felt I was doing great with it, my FTP numbers started dropping. I took a couple extra days recovery, went back to a 3-week cycle, and my FTP started back up -- after the loss of a couple months' progress.)

I was thinking about this thread this morning as I was struggling through a trainer workout. This was a Zwift workout where the wattage targets are automatically generated based on your set FTP. The set I was doing would have been heavy but not killing. Indoors, though, I was just wrecked.

I think a lot has to do with heat. Even with two fans in a cold basement, it's still a sweat fest. And not being able to rock the bike during out the saddle efforts. That's my unscientific take.

Agree about the heat. Even when my shop is 50° and I take my shirt off. Which is the reason I don't do really hard indoor workouts. The other reason is that I do all my hard workouts on the tandem, which is a big reason I don't use a PM. We're going to get wrecked tomorrow. The first climb is over 15°. We should get about 1.5 hours of Z4 and above on this ride. If I don't, as has been said, I'm either not recovered from workouts or my flu/cold bout yet. Same issue, whichever it is.

CTL is not very well correlated to a fitness peak. You want your TSB to be high which you get by dropping volume (and CTL) before a key event. Maintaining a high CTL isn't particularly difficult but you won't be at a peak in fitness until you back off.

Another factor if you're using a smart trainer in ERG mode is the way the resistance works. I struggle with this on long intervals in particular; it's hard to keep the cadence up against the relentless resistance of the trainer, which has a different feel from riding on the road. And outside, if you let your cadence drop a bit, resistance doesn't change your power just drops a bit and then when you realize it you get back on top of the gear and get your power back up. But with a trainer in erg mode, if your cadence drops the resistance increases and it just gets harder and harder; really easy to dig yourself into a hole on longer intervals; and once you're mashing at a low cadence and your legs are burning and fatiguing that much faster, it can almost impossible to get back into your rhythm. Long tempo intervals on the trainer are the worst IMHO, I'd rather do something like over-under intervals or shorter VO2Max intervals than just grind away at tempo power for 20-30 mins.

Totally agree. It's not a matter of noticing when you've trained too much. It just understanding how the ebb and flow of training goes. You don't back off on training before a key event because you have to, you back off because you should.

As we used to say in freshman dorm, one has to define their terms. I don't define fitness the way you do. I would call what you're calling fitness, "readiness to compete." My usage of "fitness" means CTL level. My power and endurance will increase with increasing CTL level, all other things being equal, meaning proportion and level of intensity which make up that CTL. IOW, when I work hard for a few months while doing a good job of apportioning intensity and rest, my CTL increases. I can ride faster and further, which to me means fitness, than I could at a lower CTL, assuming similar TSBs at the snapshot moment.

I'll drop my CTL before anything I care about, whether I'm particularly fit or not.

I disagree about how easy it is to maintain a high CTL. When I'm enjoying my highest CTL for the year, I can't maintain it for more than a couple of weeks without overtraining. If one's CTL is easy to maintain, that just means it could be higher and one could be stronger.

Just my experience.

An interesting description of how a pro rider manages their training during a season: How Tinkoff-Saxo Manages Fitness and Fatigue Over the Season | TrainingPeaks

Great article. Reading that, I have a new goal: a CTL of 180. I am gonna get so fast!

I started the year with a CTL of 68. I'm taking the slow and steady approach gaining a little over 3 pts/wk. I'll be at 180 by the end of Aug :)

That sounds about right. ;)

I just have an old fluid trainer. Power and cadence from my Quarq.

I don't like ERG at all for a lot of reasons, what you described being part of it. I much prefer doing my intervals in regular mode. In fact, I do them in Zwift in free ride, with changes of elevation and everything. I think they represent what you would face outside during a race/ride better than the constant power/cadence intervals that trainers force you to do. Doing it that way I don't mind long intervals on the trainer. Did 100 continuous minutes of sweetspot on Tuesday and it was not too horrible.