Analyzing race power output vs indoor FTP

Jun 9, 19 22:03

Post #1 of 34 (4117 views)

I am a newbie when it comes to training with power, and have yet to fully utilize the data. However, I completed a solid block of training throughout the winter that saw a heavy increase in bike volume. Within this period I set a new FTP of 273, done in aero on the trainer. Power is based off crank arm power meter.

After having done my first 2 races of the 2019 season, I am slightly disappointed with the seemingly lack of gains on the bike. After completing the Monte Rio Olympic Triathlon this past weekend, my power output was the same as that of my first race of the year at the Folsom International Triathlon (also lower than expected).

Monte Rio is a relatively flat course with a few rollers in the middle of the bike leg. There was moderate to high wind throughout the bike as it was along the coast.

My main question is what could be causing the drastic decrease in power when racing outside? I weigh 65.77 kg which would put the FTP of 273 at 4.15/wkg. Looking at Monte Rio, I had an avg. of 226 and 233 NP.
Even if I take into account Normalized Power, 3.54 w/kg is still a difference of 0.61 w/kg! During the race I felt calm and focused, and was seemingly red-lining it the whole time. From what I've read it is typical for outside power to be greater than indoor power, not the other way around. Although you typically wouldn't want to be pushing your FTP for an Olympic bike, shouldn't there be much less of a difference between it and what I rode?

The one conclusion I have come up with is that indoors, I usually hold a cadence of 80-90 rpm. This ride had an average of 96. Could I just not have done enough miles outside to get used to pushing the same cadence/power as I do inside? I have not changed my position since doing the FTP test about 2 months ago.

Open to any thoughts, suggestions, etc. Thanks!

Dominic Pollizzi

Last edited by: zestypollizzi: Jun 9, 19 22:26

Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 9, 19 22:30

Post #2 of 34 (4094 views)

This is a really dumb question, but you aren’t on a kickr or similar indoors, and then your crank power outdoors?

Reason for asking is that my kickr is 10+ watts higher than my vector 3s, and that has been consistent across 4+ hours of test riding this weekend.

Re: Analyzing race power output vs indoor FTP [Misery] [ In reply to ]

Jun 9, 19 22:37

Post #3 of 34 (4086 views)

No, I just use my Gen. 3 Stages power meter indoors and outdoors. The readings for it are pretty consistent as well and I always make sure to calibrate it.

Dominic Pollizzi

Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 9, 19 22:50

Post #4 of 34 (4077 views)

One thing I find is that my power drops when going down mild grades (ex. -1%) even though I feel like I’m working hard....something I’m working on fixing. Indoors this is a non-issue. Dunno, but you might be doing same thing.

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Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 10, 19 0:29

Post #5 of 34 (4033 views)

I sometimes find if you haven't done enough outdoor riding for awhile is that you can find it hard to mantain the real threshold power you can do, because you've got to focus on other things- handling, obstacles, other riders, not crashing, head position etc. On a trainer all you need to be worried about is to keep that power high.

for example, My FTP as recorded on the trainer is ~270 watts, but if I try to replicate that out on the road- it's really hard and I'm hitting about ~250 watts because I actually have to ride- being aware of traffic,bikes, ease up on corners, dodge holes, etc. It's not a big concern of mine though, because IMO it's quite close, less than 10%, and I'm not losing too much sleep over it.

your 50 watt loss does seem a tad excessive for that though.

Re: Analyzing race power output vs indoor FTP [davidalone] [ In reply to ]

Jun 10, 19 2:27

Post #6 of 34 (3978 views)

davidalone wrote:

I sometimes find if you haven't done enough outdoor riding for awhile is that you can find it hard to mantain the real threshold power you can do, because you've got to focus on other things- handling, obstacles, other riders, not crashing, head position etc. On a trainer all you need to be worried about is to keep that power high

I think there is a ton of truth to this, also you swam first then biked. How is your swim fitness? It could be limiting your triathlon bike leg.

I ride almost exclusively indoors. When I go outside, I have a 10bpm increase (at easy paces, hitting it hard makes the gap in power smaller) just because of the extra stimulus (extreme focus required on road surface, other riders, traffic; heat; etc).

Last edited by: TriowaCPA: Jun 10, 19 2:38

Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 10, 19 2:30

Post #7 of 34 (3975 views)

Maybe your swim and what it does to you negatively in regards to your bike. Obviously you are doing your FTP with fresh legs? If you're a poor swimmer and getting out the water gasping then I would take that into account.

Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 10, 19 2:45

Post #8 of 34 (3963 views)

A 50 watt difference between race day and FTP testing is too big to just be expected variance since it sounds like you pushed pretty hard on the bike.

Are you sure that your indoor power is reading off your crank arm, and not from your Kickr or power controlled trainer? That would be the most likely situation, with differing power readings between both.

I'd normally say swim fatigue, but even if you're totally out of swim shape, it shouldn't wipe you out as much as 50w (see youtube Vegancyclist who does a triathlon as a pure cyclist with zero swim training and near-zero run training, and still bikes fine for an Oly for his cycling ability.)

Re: Analyzing race power output vs indoor FTP [Shambolic] [ In reply to ]

Jun 10, 19 2:49

Post #9 of 34 (3959 views)

Not only the swim, but also the shape of the day?
At home at an ftp test you're really willing (if not you postpone your test to another day).
At a triathlon you HAVE to start at the moment the man fires the gun, even if you do not feel like it at the moment.

Re: Analyzing race power output vs indoor FTP [lightheir] [ In reply to ]

Jun 10, 19 2:59

Post #10 of 34 (3946 views)

On post 3 he says

"I just use my Gen. 3 Stages power meter indoors and outdoors"

So it's not a crank arm power meter but the discrepancy is still higher than expected with the Stages.

Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 10, 19 3:14

Post #11 of 34 (3931 views)

Based on your data you basically raced at about 83% of FTP which is a little on the low side for an Olympic. Realistically you should be up around 90-95% for an Olympic.
Were you monitoring power and targeting a specific power during the race or just riding by feel/RPE/HR and looking at the data afterwards?

One major change that I made over this last season was racing to power, with the top data field in my Garmin being %FTP and having a set % that I want to aim for during that race, with acceptable surges when needed. For my last HIM I targeted 85% FTP and ended up with an average power of 84.8% FTP for a 2:21 bike split.

Lots of variables can come into play on race day which can affect your overall AP and NP. If it is a congested field and you are coasting a lot you will obviously drop more. I doubt it is a calibration issue, as you mention I tend to find I ride to a higher power than expected outside than what I do inside.

Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 10, 19 3:22

Post #12 of 34 (3922 views)

Why would you expect to ride an Oly distance bike leg at 100% of FTP? You need to swim first and then run after. You held 85% of FTP. That seems like it’s in the ballpark, maybe it’s a little low, I’ll let the power experts give feedback here, but you should see a substantial decrease from an all out FTP test to what’ you do in a triathlon.

The other thing is how your FTP is measured. Depending on the estimation method used, your FTP estimate could be a bit high.

In short, don’t worry about it. Did you race well? Use power numbers to help you, not to dictate your race.

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Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 10, 19 3:55

Post #13 of 34 (3880 views)

If your cadence is markedly different between the two situations then you're doing things differently in outdoor racing than you are on the trainer so it's unsurprising your results are quite different. However, even were this not the case, I don't think your results are that out of line. Two things:
I don't agree about people always performing outside. If you've insufficient cooling and stimulation I think it's the case, but some of my strongest performances up to about 70 or 80mins in duration have been on the trainer with fans blowing and Zwift in front of me. If you're in the right frame of mind it's easier to maintain focus embrace the pain. Beyond that duration, comfort and tedium tend to swing performance back in favour of outdoor riding for me.
In a race situation, especially a multisport race, I'm a lot more aware of the need to pace myself. I'll push harder on the trainer in the knowledge that if I overdo it I can just back of a bit, or in the worst case sprawl gasping or dizzy over my handlebars (okay, you're not doing high intensity intervals in a race situation so this isn't entirely applicable). In a race over-pacing can result in a terrible run or in an extreme case, falling off the bike (again, the latter isn't likely in a race, more applicable to an all out sprint on a training ride).

One other thing, and potentially the most relevant.... how did you determine your FTP?

Re: Analyzing race power output vs indoor FTP [JasoninHalifax] [ In reply to ]

Jun 10, 19 3:57

Post #14 of 34 (3877 views)

JasoninHalifax wrote:

Why would you expect to ride an Oly distance bike leg at 100% of FTP? You need to swim first and then run after. You held 85% of FTP. That seems like it’s in the ballpark, maybe it’s a little low, I’ll let the power experts give feedback here, but you should see a substantial decrease from an all out FTP test to what’ you do in a triathlon.

Did you race well? Use power numbers to help you, not to dictate your race.

I always use power numbers to 'dictate my race'.

IMO, 0.85 IF is my target for the 70.3 bike distance. 0.90-0.92 for the oly and .99-1.00 for the sprint. So I actually do try to hit my FTP in a sprint, but it's damn hard. I hit 0.99 in my last two sprints...

To the OP-
My outside power is about 5-10watts lower. I have an embedded PT powermeter in my rear wheel. I have put the bike on both my dumb trainer and my newer smart trainer. The power as measured on the smart trainer is also 5-10 watts higher.

Re: Analyzing race power output vs indoor FTP [jaretj] [ In reply to ]

Jun 10, 19 4:15

Post #15 of 34 (3845 views)

jaretj wrote:

On post 3 he says

"I just use my Gen. 3 Stages power meter indoors and outdoors"

So it's not a crank arm power meter but the discrepancy is still higher than expected with the Stages.

Yes I knew that, but was just checking that he might not be for example, running a Kickr+Stages, and THINKING he's only getting power readings from the Stages, but is somehow having a technical glitch and actually getting indoor power off the Kickr and outdoor off the Stages despite what he thinks.

Re: Analyzing race power output vs indoor FTP [dtoce] [ In reply to ]

Jun 10, 19 4:19

Post #16 of 34 (3841 views)

dtoce wrote:

JasoninHalifax wrote:

Why would you expect to ride an Oly distance bike leg at 100% of FTP? You need to swim first and then run after. You held 85% of FTP. That seems like it’s in the ballpark, maybe it’s a little low, I’ll let the power experts give feedback here, but you should see a substantial decrease from an all out FTP test to what’ you do in a triathlon.

Did you race well? Use power numbers to help you, not to dictate your race.

I always use power numbers to 'dictate my race'.

IMO, 0.85 IF is my target for the 70.3 bike distance. 0.90-0.92 for the oly and .99-1.00 for the sprint. So I actually do try to hit my FTP in a sprint, but it's damn hard. I hit 0.99 in my last two sprints...

To the OP-
My outside power is about 5-10watts lower. I have an embedded PT powermeter in my rear wheel. I have put the bike on both my dumb trainer and my newer smart trainer. The power as measured on the smart trainer is also 5-10 watts higher.

That sounds like using the power as guidance to help you race, rather than some arbitrary number that you are trying to hold. I’m guessing that you know those percentages from experience?

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Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 10, 19 5:08

Post #17 of 34 (3788 views)

How did you determine FTP? If it was by one of the methods other than a flat our 1 hour time trial (20 mins x .095 for example) that might be your answer right there. I have worked with some athletes who can just push very hard for 20 mins - well beyond 0.95 factor of 60 mins. I personally know I need to be about 0.92 for a 20 minute test - that is just a lot of years of experimenting and experience that tells me that.

If you want your FTP on the road on rolling terrain - find a local 25 mile time trail and do one on the road. Turbo and Road numbers rarely match each other, are different % for most athletes and can cause confusion in TP with TSS scores and the like.

He who understands the WHY, will understand the HOW.

Re: Analyzing race power output vs indoor FTP [JasoninHalifax] [ In reply to ]

Jun 10, 19 5:11

Post #18 of 34 (3783 views)

JasoninHalifax wrote:

dtoce wrote:

JasoninHalifax wrote:

Why would you expect to ride an Oly distance bike leg at 100% of FTP? You need to swim first and then run after. You held 85% of FTP. That seems like it’s in the ballpark, maybe it’s a little low, I’ll let the power experts give feedback here, but you should see a substantial decrease from an all out FTP test to what’ you do in a triathlon.

Did you race well? Use power numbers to help you, not to dictate your race.

I always use power numbers to 'dictate my race'.

IMO, 0.85 IF is my target for the 70.3 bike distance. 0.90-0.92 for the oly and .99-1.00 for the sprint. So I actually do try to hit my FTP in a sprint, but it's damn hard. I hit 0.99 in my last two sprints...

To the OP-
My outside power is about 5-10watts lower. I have an embedded PT powermeter in my rear wheel. I have put the bike on both my dumb trainer and my newer smart trainer. The power as measured on the smart trainer is also 5-10 watts higher.

That sounds like using the power as guidance to help you race, rather than some arbitrary number that you are trying to hold. I’m guessing that you know those percentages from experience?

These numbers are pretty well established as power targets across the various distances, they are basically what my coach uses and also on many sites. My last HIM I was told to target 85% FTP and if I was feeling good potentially go up to 87.5%....sprints aim for 95-100% (I can never get that high in my sprints.....). For some reason I find %FTP easier to work with than the actual number itself.

Re: Analyzing race power output vs indoor FTP [Amnesia] [ In reply to ]

Jun 10, 19 5:34

Post #19 of 34 (3746 views)

I'd a similar experience recently where i wasn't able to hold planned power for a 70.3 compared to all my SIM sessions which would have had up to 70k @ planned race power with run off it etc.
Turns out i previously had a very poor kick during swim but after focusing on it i have gone to the other end and kick way too hard for the swim leg. This ~30mins of heavy kicking was having a big impact on my ability to hit planned race numbers. The time i made up with kick during swim was far less than what i lost over the bike and run legs as a result.

1500m swim having an impact on your bike??
Regarding indoor and outdoor i find them similar enough once route doesn't include many sections where your easing off power due to lights, corners etc but wouldn't be the case in your race.

Re: Analyzing race power output vs indoor FTP [Rodneyr1981] [ In reply to ]

Jun 10, 19 6:38

Post #20 of 34 (3693 views)

Well, you're talking about a planned power a lot lower than ftp for a multisport race. Not ftp power vs. ftp power for a time trial only.

Also, in a real race your pacing might take you higher and lower (your VI) than on a fluid or smart trainer at a constant output indoors.

Perhaps attempt a similar "course profile" indoors and see what you get.

It's one thing to peg it indoors in a super steady controlled situation with no other focus than suffering the output versus outdoors where you're encountering gradients and having to focus also on steering the bike.

I'd say the old Coggan "best indicator of performance is performance itself" would lead to doing some outdoor simulations to see what power you should target.

Before I did my first ever duathlon, I used the local weekly tri group ride to do a brick workout just like I'd do the race and rode behind the group a 1/2 mile at race pace to get some data.

I'd never use my indoor ftp to depend on a "goal %".

Re: Analyzing race power output vs indoor FTP [earthling] [ In reply to ]

Jun 10, 19 6:46

Post #21 of 34 (3683 views)

earthling wrote:

How did you determine FTP? If it was by one of the methods other than a flat our 1 hour time trial (20 mins x .095 for example) that might be your answer right there. I have worked with some athletes who can just push very hard for 20 mins - well beyond 0.95 factor of 60 mins. I personally know I need to be about 0.92 for a 20 minute test - that is just a lot of years of experimenting and experience that tells me that....

Yep
I'm out of shape right now but for a long period last year I could manage 305W for 20mins, giving an FTP estimate of 290W using the 95% rule of thumb. However, 285W was about the best I could do for half an hour. If I wanted to do 2x20min intervals I had limit myself to about 275W-280W. I reckon my actual FTP was probably closer to 270-275W (88.5% of 20min max).

Re: Analyzing race power output vs indoor FTP [TriowaCPA] [ In reply to ]

Jun 10, 19 7:04

Post #22 of 34 (3654 views)

TriowaCPA wrote:

I ride almost exclusively indoors. When I go outside, I have a 10bpm increase (at easy paces, hitting it hard makes the gap in power smaller) just because of the extra stimulus (extreme focus required on road surface, other riders, traffic; heat; etc).

I'm pretty similar in seeing higher HR outside and while I have different measurement devices (powertap wheel outdoors, cycleops hammer indoors), I've compared them to a 3rd meter in the past and found them to line up. I think one factor, for me, is that steady power outdoors is something that's tough for me due to the rolling terrain and I ride an 8 speed bike so finding a good gear can be tough for me sometimes. I really wonder how much smoother I could be with 10 or 11 speed. ERG mode makes training so much better for me, but I should get out in the real world a bit more.

Re: Analyzing race power output vs indoor FTP [TriowaCPA] [ In reply to ]

Jun 10, 19 7:41

Post #23 of 34 (3625 views)

I've definitely been doing the majority of my hard rides indoors since April, with only a few exceptions to that. Now that it's summer I'll start adding them back in. I'm not the fastest fish at local races, but usually come out of the Olympic swim in about 21-23 minutes depending on the conditions. I also swim in the pool 4-5 days a week .

Dominic Pollizzi

Re: Analyzing race power output vs indoor FTP [Ai_1] [ In reply to ]

Jun 10, 19 7:48

Post #24 of 34 (3609 views)

It makes sense that if I'm riding with a different style outside, then I'll be experiencing different results. Pushing hard during a race with lots of other variables is way different than just being stationary and glued to a screen. I got this FTP number after a zwift race which lasted about 50 minutes.

Dominic Pollizzi

Re: Analyzing race power output vs indoor FTP [zestypollizzi] [ In reply to ]

Jun 10, 19 8:14

Post #25 of 34 (3563 views)

zestypollizzi wrote:

It makes sense that if I'm riding with a different style outside, then I'll be experiencing different results. Pushing hard during a race with lots of other variables is way different than just being stationary and glued to a screen. I got this FTP number after a zwift race which lasted about 50 minutes.

I think Zwift bases automatic FTP updates on 95% of your best 20min. If that's the case, it's possible your race performance as a whole could have had an average power way below that FTP value, you just did a really hard 20mins at some point during it. I may be wrong.

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