Originally Posted by Tank Engine
3. Performance levels. These are in no way conclusive of doping, since they are within the acceptable range of athletic performance. This could be seen as evidence of "cleanliness". On the other hand, you might say that of the five Sky riders who have shown a marked improvement in their performance over the last year, four of those belong to the "inner sanctum" (the other being Nordhaug). One of these four, Froome had only previously shown brief flashes of form, but has podiumed 2GTs in the last year. He also suffered from a disease affecting the blood. So where is this improvement from and is the disease a cover up for a crazy passport, one might ask. In the mountains at the TdF he seemed a level above everybody else. It is natural that a cyclist of his age and history should improve, but to that degree after a serious illness?
Ok I will have one last stab at this....
Wiggins has not improved his performance in short ITTs such as prologues compared with Cancellara from 2007 through 2012.
TdF prologue 2007 (7.9km)
Cancellara = 8:50
Wiggins @ 23sec
TdF prologue 2012 (6.4km)
Cancellara = 7:13
Wiggins @ 7sec
When you plug these numbers into cyclingpowermodels, assign 7kg as bike weight and equalize wind and gradient to zero for each rider and each prologue (which are assumptions but the best we can do without proper environmental data) and you use the riders own estimated cda (but you use Hincapie's CdA from 2007 instead of Wiggins since in 2007 Wiggins weighed about 78kg which is close to Hincapie's 79) then you get the following estimated power outputs:
Cancellara = 597W
Wiggins = 529W
Cancellara = 583W
Wiggins = 526W
ZOMG! No change!!
A 5% increase in VO2max from doping means that Wiggins should at least have been matching Cancellara's time in 2012 and a 10% increase in VO2max means that Wiggins should have beaten him by about 10sec.
So basically everything hangs on the weight issue. If Wiggins lost power and he went backwards by 10-20sec over 7kms or so, then it looks as though he could have regained that from doping. If Wiggins did not lose power as a result of dropping from 77-78kg (2007) to 71-72kg (2012) then his prologue performances indicate he did not commence a doping program, or at the very least he didn't get much out of it if he did. Furthermore, Wiggins could have lost power, but improved cda or bike handling skills so that his avg velocity for a given power improved slightly. I wonder if Team Sky worked on that sort of stuff over the past 3yrs?
edit: and just in case the following point has escaped you, what the above shows is that 5-10% changes in absolute VO2max and thus peak aerobic power only make about 10-20sec changes in time over these short distances. These obviously extend out to minutes over longer distances eg: 50km but the question is how much do differences in cda and bike handling skills make?
Wiggins did 50.0kph average in stage 19 ITT of the 2012 TdF which says 462W if you apply the default assumptions (eg: zero wind, gradient etc). If you drop the cda down to 0.235 the power drops to 454 and 446 @ 0.23. Those differences are equivalent to changes in VO2max of 1.5% (if we assume that Wiggins rode at 90% VO2max for the ITT). So a drop in cda from 0.2398 down to 0.23 would mean that Wiggins could have a VO2max 3% lower and still go the same speed.
If acoggan is reading this I would be interested to know if that sort of change in cda is possible or reasonable? Is the default value of 0.2398 even correct??
Now the point here going back to the weight loss issue is that Wiggins could lose 3% of his absolute VO2max and still go the same speed in a long (50km) ITT as a result of weight loss (ie: 462 down to 446W), but lets assume 462W is his FTP @ 77.5kg and 446W is his FTP @ 71.5kg. That would change the FTP w/kg from 5.96 up to 6.24.
Comprende? A weight loss of 7kg could be achieved with a corresponding decrease in VO2max power at 3% and this would INCREASE w/kg by a whopping 9.5% but the same person would only need to improve their cda by 0.01 units to maintain ITT performance.
acoggan is the go to guy for this.... how hard is it to alter cda by 0.01 units????????