Correlation between Conconi (Ramp) Test and 40k TT (FT) Test

Bruce Diesel

Hi All,

I am fairly new to cycling (18 months) but have been working with a trainer since the start. This week I performed a Conconi Test on a Cardrigus Ergometer and I am having trouble correlating the results of the Ramp test with my Functional Threshold. Tomorrow I will be doing a 40kTT test on my bike with a powertap and a Cateye CS1000 indoor trainer. I am trying to work out what power I should aim at in order to pace myself (I have never done a 40kTT test before).

THe results of the Conconi, which I understand gives me my MAP are 523.5W at 159 bpm (HR). I currently weigh 77.8kg giving me 6.7W/kg at MAP. My max HR is 184bpm. My age is 37.

Trying to read as much as possible, it is my understanding that I should be aiming at 72% to 77% of MAP as being my FT.

This is where things go wrong for me. I should be between about 370W and 400W for FT. Yesterday I tried to correlate these outputs with RPE so that I can try to pace myself in the TT. My problem is I cannot maintain 370W for anything like 60minutes - closer to 5 - 10 minutes. From an RPE perspective I feel my FT is around 320W.

What is wrong with my logic?
1. As I have not been cycling very long, would be FT be significantly lower than the 72% - 77% range?
2. Can there be this much discrepency between Cardrigus and PowerTap?
3. Have I misunderstood the concepts of MAP and FT?

Any help would be much appreciated.

Spunout

As you are doing the two tests on different equipment, expect some variability. Zero the torque on your PowerTap.

Where was your HR-VT on the Conconi test? This can also correlate to your HR-FT.

If the testing/training equipment checks out, you may have done an incredible Conconi test but have no FT endurance. This may be the case in your untrained state. Start with a 20 min TT to guage your FT, and then try a 40km TT starting 10 watts under that.

Bruce Diesel

I'm not sure what you mean by HR-VT?

I'm not untrained at the moment. I raced competitively last year and these numbers are similar to numbers I achieved last season. My trainer is very happy with my power, but tells me it will take a couple of years longer to reach cycling potential. Which may be another way of saying it will take time to get my FT to where it should be.

Road racing wise I am able to respond to attacks and get into the breaks, I have trouble sustaining them - so maybe these results are correct?

acoggan

1. It's possible. Alternatively, you may just have a higher-than-average anaerobic capacity, which will skew your power at the end of an incremental exercise test upward relative to what you can sustain for a prolonged period of time.

2. This is also possible...and given your weight, age, maximum heart rate, and cycling experience, a MAP of >500 W strikes me as surprisingly high.

3. It doesn't sound like it, although it does appear that you misunderstand the Conconi test protocol. Specifically, this consists of performing an incremental exercise test with a very rapid increase in exercise intensity while attempting to identify a deflection in heart rate, which is supposed to correspond to your maximal lactate steady state/critical power/functional threshold power. In reality, however, it doesn't work, as A) many people don't show an identifiable deflection in heart rate, and B) even in those who do, it doesn't correlate with any lactate-based or performance-based measurement (nor would you expect it to, since there is no known mechanism by which a deflection in heart rate would be linked to such measures of metabolic fitness).

rmur17

Can you describe the Conconi test in detail? Starting power, power increment per step, time per step?

If it's equivalent to a BCF ramp test to failure then FT ought to be around 75% as you describe. Power measurement differences is another source of error as has been mentioned ..

rmur

peterwright

Hi Bruce

We use the Cardgirus ergo's and for what it's worth, although the power seems similar to the PT, I have managed a 20km TT of 315 on the CG but can only achieve 288 on the road with the PT - so I would recomend a 20km TT on a repeatable road course with the PT (trainer will also elicit a different power) and then .93% to establish FT for training zones. Far simpler and less onerous than a 40km TT that you probably won't want to repeat as often as you should - a 20km TT can be built into a 2X20 session every other week if you choose (this is what I do)

Cheers

Peter

Bruce Diesel

I agree that the 500W number seems to be extremely high - given all the literature I have read, this is why I am concerned about the Cardgirus Ergometer.

With regards to the Conconi test outcomes, the LT inflection point is calculated by software - I am not sure how this works? My assumption is that the LT calculated by the software is in fact my MAP and not my FT. Unfortunately my trainer is away for 3 weeks so I can't ask him about this.

The test protocol is initial speed = 20km/h, Speed increase 2 km/h, Seconds per section = 60. I reached a final speed of 50km/h (power = 587.2Watts).

I believe the Cardgirus Ergometer is a good piece of equipment, however, even good equipment can be out of calibration.

Interestingly though, in CyclingPeaks my mean maximal power for 1 minute is 470Watts so??? This is from the last 28 days in which I haven't pushed as hard as possible.

Bruce Diesel

Hey Peter, good to see you on another forum!! I've seen the .93 20min protocol as well - that should be achievable here in Jhb!!

The difference you are talking about between Cardgirus and PT is 10%, which is significant!

rmur17

Are you riding 20km in 20 minutes? For me that's closer to 30min and taking 0.93 of that would underestimate my FT appreciably.

I think such fudge factors are appropriate ONLY when you have enough personal data on your Power-Duration curve to trust them. What's 0.93 for one person could be 0.9 for another and 0.98 for yet another. That's a big spread when looking at TSS for instance which is proportional to (1/FT)^2.

Just something that keeps coming up. Maybe it's all covered in the manual

rmur

acoggan

Not, as I recall, in great detail (keep in mind that one faces certain constraints when producing a multi-author manuscript for a publisher that hopes to turn a profit on your words).

peterwright

Noted, what %age is appropriate for estimating FT based on a 25 -27 min effort ?

Spunout

No, usually the highest power (completed ramp or portion of next) in a ramp test is your MAP. LT would be lower, and may be closer to FT.