Back then I would normally race at 69 to 70 kilos. These days I ride at 66 kilos.
This confirms it, then. That was the 2009 Giro, when he was still with Barloworld. At one point in the interview with Kimmage he says 70/71 kilos, and Mantovani, as quoted in that interview, threw out 72 kilos, but it seems that his normal racing weight was 70, or even less.
By the way, saying he finished 120th I gather is supposed to make the reader think that his racing was really affected by his weight—perhaps to set us up for believing when he lost weight he got much better—but in fact that was not a mountain stage, and Froome finished in the pack.
bewildered said:
to when does 'these days' refer? when did he sit down with Walsh to write that bit? After Grappe?
I assume so. Again, you have to take Grappe as the authority here. If he says Froome weighed 68 kilos throughout the 2011-2013 period, then Froome either lost the extra weight later, or is simply not telling the truth.
Another thing to add: If he did not increase absolute power while losing weight, and was able to put out 459 watts when he weighed 70 kg, then assuming a 90% lactate threshold, his efficiency would have to be about 24.5%.
How realistic is that? I thought the usual range for efficiency was about 18-23%, e.g., see
Coyle et al (1992). However, I found
this very interesting study of eleven elite riders:
Several of the present subjects are among the best cyclists in the world, according to the ranking of the International Cycling Union. To ensure that all of them could be really considered as "world-class" riders, they were required to meet the following requirements: 1) have participated in the mean competition's of the professional category (e.g., 3-wk tour races) and 2) have won at least one major professional race (e.g., one or more individual stages and/or final classification of a major 1-wk or 3-wk race (Giro d'ltalia, Tour de France, or Vuelta a Espana), or Top 3 in World Championships).
One of them is later described as a two-time world champion. I will return to this. Also of interest are their blood parameters:
Mean values of hemoglobin and hematocrit averaged 14.7 ± 0.3 g-dL~' (range, 12.8-16.1) and 43.5 ± 0.7% (range, 39.9-46.5) and thus were within normal, physiological limits for endurance athletes (27).
Now what about their gross mechanical efficiencies (GE)? Several of these subjects had GEs higher than 24%, in fact the mean was 24.5% and the highest was 28.1%. The authors claim this is typical of elite riders:
The values of GE obtained in the present study (~ 24%) are similar to those recently reported in professional riders at the power outputs eliciting the lactate threshold (L T) and the respiratory compensation point (RCP) during a ramp test (14), and higher than those previously measured in not highly trained cyclists (average of 20%).
But they also found—as has also been found in endurance runners, and which motivated the study—that
there was an inverse correlation between efficiency and V02max/kg. In fact, the highest V02max/kg value of any of these eleven riders was 82.5, and the mean was 72.0. Moreover, only one rider with an efficiency of > 24.0% had a V02max/kg of > than the mean of 72.0, and just barely: 24.1% and 76.1. Using
Alex Simmons' power curves, this corresponds to about 5.75 watts/kg.
The authors also say:
The best rider in the present study (e.g., two-time world champion) showed a relatively low VO2max value (slightly below 70 mL-kg~1-min""1) but very high values of both CE and GE (clearly above 90 W -L^-min"1 and 25%, respectively).
This rider had one of the highest efficiencies, at 28.1%, but because his V02max was so low, his watts/kg is estimated at 6.1, still within the range most people think is possible without doping.
This is the highest estimated watts/kg value in the group.
FWIW,
Coyle's study of Armstrong more or less fits in, with a reported V02max of 85 and a GE of 21.5-23 (Coyle of course controversially claimed GE rose over time). This results in an estimated 5.75 watts/kg, based on 85% LT (Coyle said it was 75-85%). Note, though, that this estimated value is far lower than many of the values estimated from LA's climbs, e.g., Alpe d'Huez.
The authors conclude:
The main finding of our study was that, in professional world-class cyclists, both CE and GE are inversely correlated to VO2max (either expressed in absolute or relative units). It follows that a high CE/GE could compensate for a relatively low VO2max in these athletes.
Who were these elite riders? They aren't named, but there is a hint at the end of the paper:
This study was financed by Asociacion Deportiva Banesto.
This is one of the most interesting and useful studies of riders I've ever seen. I wish there were more studies like this (it was more than ten years ago). What implications does it have for Froome? On the one hand, if GEs as high as 28% are really possible (and probably higher, as only eleven riders were studied), then in theory he could put out his Madone 459 watts with a V02max of just 80. Even the mean GE in this study of 24.5% would require just 90.
OTOH, as the authors emphasize, there is a fairly strong inverse correlation of GE and V02max, so that it would seem highly unlikely that someone with a V02max in the 80s or higher would have such a high GE. Only two riders in this study had a V02max of > 80 (they were the only riders > 77, in fact), and one had a GE of 22% and the other about 21%. At 90% LT, that is only about 5.6 watts/kg.
Is Froome a freak, combining a V02max and GE never before seen? As I pointed out before, if he is, so it seems is Porte, who was reported to trail Froome by only fifteen seconds up the Madone, implying a V02max/kg of 6.85-6.90. To put that in perspective, their power output would beat Pantani's record up Alpe d'Huez by more than a minute, even allowing for the fact that Alpe is a little longer, and therefore there would be some reduction in power.
And to be fair, the Madone is quite a bit shorter than the times usually considered for power curves, perhaps an hour; the watts/kg value would fall significantly over a longer interval. Based on Grappe's report, in which he says Froome loses 60 watts going from 20 min to an hour, 459 watts for a little over 30 minutes would be around 420-430 for one hour. But that still indicates a very high watts/kg value at 66 kg, and keep in mind that 90% LT is very generous (in the sense of lowering the V02max required). With 85% LT, e.g., and 420 watts/66 kg., the efficiency is about 24.5% for a V02max for 90, which still seems to be a considerable outlier.
Ever since Froome released this time and power (though as I pointed out before, the time and power do not seem to match), I've been wondering why he would do this yet refuse to release power data from races, except to Grappe, and even then only post-Vuelta. I'm speculating now that it's because he anticipates being pushed hard by Contador in the TDF, and having to put out extraordinary times up certain climbs to win. By putting out this power value now, he can point out that any time he does in the TDF is completely consistent with what he was doing up the Madone. IOW, an attempt to lessen the shock value.
One final comment. This study was done in Spain. I assume the two time WC referred to was Oscar Freire. He apparently had the highest estimated watts/kg value, yet he's not of course an elite climber. That suggests to me that perhaps all these subjects were guys who won classics or breakaway stages, and not representative of those in the peloton with the very highest power/weight values. Something to keep in mind.
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