Did first CP tests, have questions

PSUcycling

I did my cp tests this afternoon for the first time and now have a few questions.

1. I didn't click off the intervals as i went, (I thought i could go back later and get a good average from the graph). The powerlink software graphs your M.A.P. based on the current ride. How accurate is the MAP section, compared to clicking off the interval and looking at it seperately to get my average?

2. at 66kg how does my LTPower compare at 300watts for 20mins?

thanks

JMc

jws

You should start by reading "Power 411" at:

http://www.cyclingpeakssoftware.com/

I'd recommend buying the software for $75(I think); PTlink is garbage compared to CPS.

More info at:

http://www.midweekclub.com/articles/

PSUcycling

Thanks jws,

I have read those links, however, I am still looking for some info on the validity of the M.A.P. section of the PowerLink from others with this program.

John

biker-linz

Hi JMC,

Firstly, what do you mean by CP tests? Are you referreing to Joe Friel's misuse of an existing scientific term, or do you mean the type of CP tests suggested by Monod et al (and many others)?
As I don't use the Powerlink SW (even though I have a couple of PTs), what does MAP stand for. Most of us use it to mean Maximal Aerobic Power, but again there is a specific test protocol for this.

L.

__________________
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RST Associate Coach
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in.10.city

Explain this if you may - "Joe Friel's misuse"... How is CP6, CP30, ... defined differently?

acoggan

As Lindsay alluded to, "critical power" is a term that has been used in the scientific literature since the 1950's. Friel's decision to label your "MAP" (maximal average power, which is what it stands for in the PowerTap software) over different durations as your "critical powerS" was therefore an unfortunate one, as it has created unnecessary confusion.

BTW, "MAP" can also be used to stand for "maximal aerobic power", which is how Ric Stern/the BCF use the acronym.

PSUcycling

Thanks all,

I did notice a discrepency in the way that Friel defines both CP and MAP as opposed to others. My problem is that after doing 4 CP tests (per Friel) I'm not sure what to do with those exactly. I'll give you a run down of that work out....

40min warmup, with 3x15sec jumps (this is part of my typicall pre-race ritual).

then, 12sec interval, 1 min interval, 6min interval and finally a 20min. cooled down for 45mins. all intervals were treated as TTs and were done at my max power.

The computer defined my "map" @

12secs - 963
1min - 527
6min - 324
20min - 300

all @ 66.3 Kg that morning.

all of these numbers seem pretty close based on what i was seeing on the graph and while i was riding.

Total ride time 2hrs

Since, I did not manually click off when I started and stopped each interval (My thinking was that I could go back into the program and select each interval, but the program does not let you get that precise....) I was not able to get real definitive numbers. The Newest Powertap software (which I am currently using) seems much better than the junk they sent me originally. After each workout is down loaded, there is a TAB labeled MAP that goes through and charts your "MAP" for you.

My original question was for someone who had experience with this program as to its accuracy. However, any other feedback, ideas etc... are welcome.

thanks

JMc

beerco

I'm sure that the software does a better job of picking intervals than you can actually. CPS does the same thing.



4.5w/kg for 20 min sounds pretty darn good to me (much better than what I can do), but your LT power is well below that.

p.s. make sure your PT is zeroed. Another guy kind of made a fool of himself here by brandishing some numbers that were um, a little inflated

PSUcycling

Thanks,

that is the point though. The software will not allow me to pick specific time points to call an interval. You can get close, but i keeps adding a couple of minutes to each side, which obviously screws up your average because your power goes almost to zero.

as for numbers, I was just trying to get a reference, I had no idea if those were good or bad. Brandishing??

JMc

PSUcycling

I went back and looked at a few of my last rides and noticed the tq values seem odd compared to watts..... one ride had a max of 572 watts but only a tq max of 12in-lbs the other max of 1091 W with a 45in-lb tq. max. Does that sound right???? Tomorrow I'm going to do the stomp test.

JMc

beerco

Without cadence values, you can't tell if those are good numbers or not. If you're aware of the stomp test I'm assuming you've read the power faq etc.

Most importantly just check the zero at the start of every ride. In fact, re-zero at the start of each ride just in case it's on the verge of 0 and 1. I can't remember the last time I saw a non zero torque offset on my powertap (second year running it) but those things tend to happen exactly when you don't want them to.

To check the file, just look for zero power with non zero torqu or areas where you were coasting which show up as non zero power.

acoggan

The torque values recorded by the PowerTap/displayed in the Link software are practically meaningless, since they are measured at the hub, not the crank. Consequently, they are gearing-dependent, i.e., for the same torque applied to the crank, the torque at the hub will be higher when the gear ratio is lower, and vice-versa. (As anybody who has ever tried to remove an old-fashioned freewheel with a large cog already knows!) It is possible to calculate the crank torque from power and cadence data, but doing so requires accurate cadence measurements, i.e., use of a PowerTap Pro with crank sensor, and not the original PowerTap with its "virtual cadence" feature.

acoggan

The durations at which you tested were different, but this should still give you some feel for things:

http://www.cyclingpeakssoftware.com/profile.html

acoggan

Isn't this a question you should really be asking Friel?