Help needed to interpret a Race file

Discussion in 'Power Training' started by MY02_STi, Feb 18, 2007.

  1. MY02_STi

    MY02_STi New Member

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    First a bit of background........the 'race' was really a Club ride consisting of 5 teams of around 10 riders each, starting on a handicap basis (we started second last and stayed away to win :cool: by just under 2 minutes). The course was a semi out & back (rolling terrain) with 1600m vertical ascent (2 major climbs of around 4km each at 5% and the final climb of 3 km at 4%).

    I've had a PowerTap SL since mid January (after struggling with a Polar unit for too long) and despite some test efforts (both on the trainer and on the road) I'm still not sure what my FTP is, and after yesterday I'm still not sure.

    With the PowerTap I had determined my FTP to be 300W using two points (10 minutes and 20 minutes) in the CP model.

    The data I downloaded (I've attached the WKO+ file - the race is called Germaine Birthday Race) for the 'race' showed I averaged 250W for the 2 hour 22 minute (86.3 km) with a 300W NP reading. The range I've indicated on the graph is 272-317W based on an FTP of 300W. The three climbs can be identified by the very 'flat' power output in this power band.

    The heart rate data I downloaded from my Polar HRM (I find it far more reliable that the PowerTap heart rate readout) also showed that I had operated within my 'typical' L4 HR range (83-92%) for around 1 hour 45 minutes) so the effort was 'full on' for the entire ride.

    I was fresh and EXTREMELY motivated to ride well (+3.3 TSB, CTL 129.3) :D

    Basically, can I still take my FTP to be 300W as theoretically I should be able to maintain a higher level for a shorter period of time :confused: OR the 300W is 'about right' due to the variable/on-off nature of the ride (it was a pace line/TTT effort from start to finish :confused:

    Any interpretations or advice would be gladly received :)
     
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  2. Alex Simmons

    Alex Simmons Member

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    Sounds like fun although I don't quite get the format. You started 2nd last but stayed away? Does that mean you caught/passed everyone else?

    I can't see the file from where I am at the moment so can't comment specifically on that.

    How did you generate the 10 & 20 min data points for the CP model? Cherry picked from other ride files or full on tests?

    For you I think NP from a hard 1 hour effort would be a strong indicator of FTP, so 300W NP for 2+ hrs would suggest an FTP > 300W to me. Out of curiosity, look at your CP model and see the % difference it suggests for 1 hr vs 2 hr power.

    What was the mean maximal 1hr NP? You can't see that directly from the file. Two ways to ID it:

    (i) In the ride journal page, create a mean maximal power chart for the ride using NP as the channel and scroll pointer until you show NP at around 1hr mark.

    (ii) In the athlete home page create a chart showing mean maximal 1 hr NP for the last, say, 7 days and look at the day in question.
     
  3. MY02_STi

    MY02_STi New Member

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    Alex

    1. Yep, our elite riders (and some of them are VERY young and VERY good) started twelve minutes behind us and they didn't catch :D but we caught the 3 teams ahead of us (the last one only about 10 km from the finish)
    2. Nope, full on tests (on the road - 10:00 test [climb] out of Bobbin Head on the west side (360W average), 20:00 test flat] along Mona Vale Road out to Duffys Forest (319W average)). I don't seem to be able to generate the same power on the trainer :eek:
    3. CP model predicts 300W for 1 hour and 294W for 2 hours (296W for 90 minutes) so not much difference :eek:
    4. 317W NP at 1:00:29 ;)

    Thanks for your input
     
  4. NomadVW

    NomadVW New Member

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    I'd use the 317 (1 hr MM Pnorm), at least (I like round numbers, so I'd go with 320). Worst case scenario is you can't complete your first week of efforts at the new numbers and you back it down a notch to 315 or 310.
     
  5. Alex Simmons

    Alex Simmons Member

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    Race motivation is a wonderful thing! Were you fresh/motivated for CP tests?

    I suppose you will know how well this number stacks up when/if you do some structured interval work, especially L4s or another hour long race pace effort.

    Remember that a hard 1 hour NP is typically within 5% of FTP. 1hr NP max = 317W. Less 5% = 301W. Given your CP data, that would suggest to me you are probably somewhere between 300 and 317W (not allowing for the fact that if it was only a 1 hour effort perhap there may have been a tad more available).

    Since you have 2 methods now, each within the tolerance range - I'd split the difference and go for 310W. Over time, settle on a protocol that you can repeat and which gives you a consistent number. That is probably more important (unless you really need to nail a number for 1 hr TT pacing).

    Lower power on trainer is not uncommon.
     
  6. MY02_STi

    MY02_STi New Member

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    Aound 310W sounds good to me...thanks :)
     
  7. MY02_STi

    MY02_STi New Member

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    I was quite fresh and definitely motivated for the CP tests ;) so I feel that the data is quite valid.

    Thanks (again) for the advice and help - now at least I know that I'm in the right area ;) for FTP so I can now move forward with a fair degree of confidence that what I'm doing is correct :D
     
  8. rmur17

    rmur17 New Member

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    all sounds good - well except for using the CP-Monod model to predict power out to the 2-hr mark. I would definitely not suggest doing that. Perhaps one of the ex.phy. blokes can explain in detail.
     
  9. Alex Simmons

    Alex Simmons Member

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    Agree, however I was really only suggesting they look at how their race motivated 2hr vs 1hr data looks vs what CP says. I'll take actual performance data over CP model any day for that!
     
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