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Help me understand this..

So I'm learning more about power and want to uses my PT for more than just a speedometer. I've read Training and Racing with a Power Meter, bought the online course EN put together and I'm working through that.

 

Today's ride :

2h 54m

50 miles

NP of 164 ... my Z4

TSS of 265 ... still on the fence about this one as to what it means , help please.

IF of .956 ... not sure about this either ?

 

So I feel like I worked hard, came home for my 1st brick of the season 30 MIN and progressively ran slower but tried to maintain cadence.

 

The group I was riding with were pace lined, even the folks on tri bikes. I stayed in the back.... far... and did the work. Was that a good move or should I have paced with them ?

 

Comments

  • TSS is training stress score it is calculated on how hard you went (for you based on your FTP) and how long you went. There is some pretty fancy math involved, but the longer and harder you ride the higher it gets. a 40k all out bike should net around 100. A well executed half ironman around 180, full ironman 275ish. 265 is pretty high for a 3 hr ride. I rode pretty hard the other day for about the same time and was around 195 tss. To get an accurate TSS you must have an accurate threshold entered into the software /computer/wko you are using.
    IF is intensity factor. 956 suggests you rode to 95% of your FTP. There is some good videos in the wiki that helps you understand power even better. If you are asking questions and interacting though you are doing the right thing. image
  • The FTP you are using to calculate the other scores (TSS and IF) is too low. By definition, the FTP is the maximum power you can sustain for an hour, collapsing after that. That's an IF of 100% (1.0) As Dan implies, a good IF for an HIM bike ride (3 hours) is 75-85%. It's highly unlikely you can ride @ an IF of 95% for three hours. So you need to get yourself a new FTP before you can make a meaningful assessment of today's ride. Luckily, you don't have to re-test; you probably have the data you need to make a rough and ready assessment. If you have WKO+, you can load up today's ride, looking at it in "Graph View". Over on the right hand side is a column where you'll see "Entire Workout", below a series starting with "Peak 5s" ... and ending with "Peak 60 min".

    For fun, start by selecting "peak 20 min", and see what the NP down below is. Take 95% of that, and you've got a good estimate of your FTP. Check the 30 min and 60 min options as well to get more of an idea. Also, in the "Athlete Home" view, find the "Mean Maximal Power" chart. Double click it or choose zoom from options to make it bigger. The vertical axis is watts, the horizontal is time. "Hover" the pointer over the curve art various times like 20, 30, 40, and 60 minutes, and you'll see the maximum watts yoou have produced for that time period in yoour recent rides. Somewhere between the 30 and 40 minute numers is probably your current best guess for you FTP.

    Why might your FTP be too low? A few possibilities: it was based on indoor testing sessions and now you're outside. Or you have improved a lot since your last test. or your PT needs to be manually zeroed (instructions in their manual). I'm sure there are others, but in the end, the main thing is you need a new FTP to be able to use derived scroes like FTP and IF.

    As to how to use these scores, I suggest reading this article by Hunter Allen, the guy who (literally) wrote the book about training with power. It's a good overview of how numbers like TSS are derived, and how it can be used in assessing the progress of your training, rather than just analyzing an individual workout.

    As to staying in the paceline vs staying off the back and "doing the work": it all depends on how fast they are. If you can get good work by being in the line, go for it. If they are too slow for you, then you need to get into the wind more on the front or off the back. It's often better from a psychological perspective to ride with others, but getting your work levels in can be tricky in a group. You have to manage not only your power levels, but also group dynamics. Sometimes it's better to announce your intentions/needs at the start of the ride; you might find a subset of folks who have a compatible plan that day, and can work with you on it.

    E.g., today I was riding with 8 or so other riders, half of whom are training for the Honu HIM June 4. Those 4 said up front: we'll be doing 3 hours, stopping as little as possible (meaning one pee break), and doing 4 x 25 min intervals at our HIM pace, with 5 min easy in between. OK, so I know what to expect, and could lead or follow as I saw fit, but still get in the comraderie of being with my buddies (half of whom are women less than half my age, which makes it a VERY GOOD RIDE GROUP!) The bummer was, I'd let the battery on my Joule wear down, do I had no power data, and had to go by HR and RPE, but that's good training as well, I suppose.

  • @ Dan, yes I looked up the math in " Training and Racing with a PM ... slick.. The numbers didn't jive with me as well so I posted looking for help. I haven't had the opportunity to look at the " numbers " because I just got out side and when I down loaded them I thought ... WTF... so let the learning curve begin..

    @ Al, As suggested to Dan, I thought something was funny with the numbers.
    You are right on as to " testing " , my numbers in PowerAgent are from inside training. I went to retest on Wednesday but got a flat had to cut things short headed home , got another flat and a mosquito bite, called the wife and said come get me. I have to go to work.
    So I don't know if I can guesstamate my numbers with PowerAgent or not.
    As for the gang I ride with good suggestion as to letting them know up front my plan, maybe I'll have takers. I thought pace riding a no no but ok, when in Rome....
  • @ David - Last year I trained with some young men - 35-39 AG - who are sub 10 hour Ironmen, with bike splits about 30 minutes faster than mine. It worked very well for me to just tuck in behind them for miles. Holding their speed while drafting was perfect for 85% work for me while they were doing 75% for them! And with the group I'm with this year, it's just the reverse - my 80-85% is perfect for them to draft about two feet behind me for their HIM training. Of course, the fact that we're all triathletes, not roadies, makes it a lot easier to work for/with each other - we understand the neds involved.

    You can create intervals in PowerAgent, using the "Details" view. Just select a likely looking 30 minute +/- section where it seems the watts are holding fairly steady, and check the resulting NP.

  • Normalized Power, Intensity Factor (IF), Functional Threshold (FT) and TSS for dummies:
    Normalized power is just a way to give a little more weight to hard work vs easy work. Example, if someone rides very steady for 1 hour and holds exactly 150 watts for the entire time, then their average watts are 150 watts per hour. If person 2 rides steady for 30 minutes at 100 watts and then 30 minutes at 200 watts, their average will also be 150 watts. Same answer, but most would agree that the second workout would be harder than the first. The math would calculate average power at 150 watts and something called normalized watts at some higher number, say 160 watts. The IF number simply compares your best one hour power number (or estimate of it) to the normalized power number of the ride. So if your best one hour power number, also called your FT is 320, then the ride IF would be 0.5 (160/320). TSS is then simply a measure of that effort over time where TSS = hours x IF squared x 100, so in this example assuming a two hour ride, TSS = 2 hours x an IF of .5 ^2 x 100 or 50 TSS points. Because the IF number is squared, it makes a huge difference in TSS if you push really hard so for example an all out one hour push nets you 100 TSS (1 hr x 1.0 IF x 100 = 100 TSS), where a leisurely ride for two hours at an IF of 0.5 gets you only 50 TSS.

    See Dan's post above for reasonable estimates. As Al noted, if your rides don't make sense from a TSS perspective, it's usually because your one hour power test estimate is off.
  • @David, I feel I should also give a plug for the power webinar put on by several smart folks that is for sale in EN store. Very good and well worth the cash.
    http://www.endurancenation.us/store/resources/ebooks_power_webinar.php

    You are in the right place asking the right questions. Rest assured.
  • @ Tom, IF got it, FT got it, TSS understand it and its math ! My poweragent figures all that out for me thank God. Thank you for the information !

    So a recap of what I learned from this post and the research I have done on ALL your input.

    NP is the real deal in watts as to what you rode, unlike on a trainer it takes in account all the variables one encounters on a ride.

    FTP , you test for it , plug in your results and get your zones, or do the math itself,

    IF, NP of interval divided by ones FTP measured by the best 1 hour of the ride. Values for IM .68 - .75, HIM .80 - .85, Short course .93 - .97

    TSS, training stress score, a measure of IF over time. According to the Power Webinar I'm working through one should stay in a particular number/zone to have an effective run.

    My ride as listed above with an IF of .956 for 3 hours suggests I need a retest because that number I held for so long indicates my FTP is off in my Poweragent Software because its to close to 100 % which I should only be able to hold for an hour.

    So learning about Power why isn't there a power tap that displays IF, TSS and even NP vs. watts, mph, hr and all the things we don't talk about here ? Such as my wired Power Tap.

    @ Al , I did look up that information as suggested by you., I took a 30 min spot and could maybe add 10 watts to my Poweragent profile. PA will not let me. It wants a 4 min all out followed by a 30 min ride to THEN give me an additional 10 watts. It really kind of sucks cause coach wants us to do 2 x 20 + the 2 min rest time for a test.

    @ Dan , Thanks got it and am working through it.

    Does anyone else have any input to this post , please feel free to add I'm all ears and will work to understand this concept.

  • So learning about Power why isn't there a power tap that displays IF, TSS and even NP vs. watts, mph, hr and all the things we don't talk about here ? Such as my wired Power Tap.

    There is it is called the joule. you can see everything live.

    As for the power agent software. Make sure you are running the latest version. You can input your FTP in the new version.
  • @ Dan , get the heck out of here WOW how much is that ? Sure would be a nice Fathers day Gift , ha ha.....

    My version is up to date perhaps operator error, could you help me out with that. I tried changing my FTP and nothing , am I doing something wrong ?
  • open power agent, click on your user on the left side. Click the power zones tab, enter your FTP (result of your 2x20 2') test in there. Click OK.
    If your PT is wired then you need a new hub. I would say on the low side 1200, 1500 on the high side for a new setup. Since you need a new wheel. I (and others) have thrown down some pretty good races w/out the joule. You can race just fine without it.
  • Thanks, just a bit more than I expected. My wired PT is built into a 404 with it's hub. I guess since I have the race wheel a need hub could be built into it. Unlike just getting the new CPU head ( cheap ) the hub is where the dough is. So much for that idea for for now....

    Al wrote me and told me how to enter the FTP in PowerAgent too , same as you. Even though my PA is up to date it will not generate anything unless I put in a 4 min value and 30 min value.
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