4 minutes vs 40 minutes

2010 Track:

2 Rohan DENNIS SA AUS19900528 56.30 4:15.764
4 Michael HEPBURN QLD AUS19910817 54.93 4:22.163
7 Luke DURBRIDGE WA AUS19910403 54.09 4:26.200

2010 Road:

1 241 Rohan DENNIS SA 46.38 36:13.27
2 239 Luke DURBRIDGE WA 46.17 36:23.16

1. [AUS] DURBRIDGE Luke JAS 31'44"
9. [AUS] HEPBURN Michael JAS 01'04"

1. [GBR] MILLAR David GRM 47'19"
3. [AUS] DURBRIDGE Luke JAS 01'01"
6. [AUS] DENNIS Rohan JAS 03'03"

1. [USA] PHINNEY Taylor RSH 42'50"
2. [AUS] DURBRIDGE Luke JAS 02"
5. [AUS] DENNIS Rohan JAS 47"

2011 Track:

2 Rohan DENNIS SA AUS19900528 56.83 4:13.399
3 Michael HEPBURN QLD AUS19910817 55.63 4:18.852
4 Luke DURBRIDGE WA AUS19910409 55.03 4:21.681

2011 Road:

1 Luke DURBRIDGE WA AUS19910409 48.71 33:23.01
2 Michael HEPBURN QLD AUS19910817 47.51 34:13.29
7 Rohan DENNIS SA AUS19900528 46.27 35:08.40

1. [AUS] DURBRIDGE Luke JAI 42'47"
3. [AUS] HEPBURN Michael JAI 46" (lost 20 seconds or so in a fall)

2012 Road:

1. [AUS] DURBRIDGE Luke OGE 46'20"
4. [AUS] HEPBURN Michael OGE 01'10"

2013 Road:

1. [AUS] DURBRIDGE Luke OGE 43'26"
2. [AUS] DENNIS Rohan GRS 21"

What is the explanation for someone being significantly slower over 4km but faster in long efforts? If the IP is such a great predictor why does Durbridge keep winning on the road?
 
Mar 13, 2009
16,856
0
0
Ferminal said:
2010 Track:

2 Rohan DENNIS SA AUS19900528 56.30 4:15.764
4 Michael HEPBURN QLD AUS19910817 54.93 4:22.163
7 Luke DURBRIDGE WA AUS19910403 54.09 4:26.200

2010 Road:

1 241 Rohan DENNIS SA 46.38 36:13.27
2 239 Luke DURBRIDGE WA 46.17 36:23.16

1. [AUS] DURBRIDGE Luke JAS 31'44"
9. [AUS] HEPBURN Michael JAS 01'04"

1. [GBR] MILLAR David GRM 47'19"
3. [AUS] DURBRIDGE Luke JAS 01'01"
6. [AUS] DENNIS Rohan JAS 03'03"

1. [USA] PHINNEY Taylor RSH 42'50"
2. [AUS] DURBRIDGE Luke JAS 02"
5. [AUS] DENNIS Rohan JAS 47"

2011 Track:

2 Rohan DENNIS SA AUS19900528 56.83 4:13.399
3 Michael HEPBURN QLD AUS19910817 55.63 4:18.852
4 Luke DURBRIDGE WA AUS19910409 55.03 4:21.681

2011 Road:

1 Luke DURBRIDGE WA AUS19910409 48.71 33:23.01
2 Michael HEPBURN QLD AUS19910817 47.51 34:13.29
7 Rohan DENNIS SA AUS19900528 46.27 35:08.40

1. [AUS] DURBRIDGE Luke JAI 42'47"
3. [AUS] HEPBURN Michael JAI 46" (lost 20 seconds or so in a fall)

2012 Road:

1. [AUS] DURBRIDGE Luke OGE 46'20"
4. [AUS] HEPBURN Michael OGE 01'10"

2013 Road:

1. [AUS] DURBRIDGE Luke OGE 43'26"
2. [AUS] DENNIS Rohan GRS 21"

What is the explanation for someone being significantly slower over 4km but faster in long efforts? If the IP is such a great predictor why does Durbridge keep winning on the road?
track legs require sometime on the boards til you get the suppleness (thats not the word, brain memory work dont).

Durbo might just hate being on the boards.

who said his wattage at national team training camps, prevented him from getting a spot in the 5 in the TP at London. the just 18yo, Alexander Edmonson got a gig instead. He could go 3'55" and he was only 17 and nearly 12 months at one point. dont know what he gets in del Monte.
 
Apr 14, 2010
727
0
0
Ferminal said:
2010 Track...
The reason why Durbridge dropped out of the Australian Team Pursuit quartet early (I think 2yrs before the Olympics and younger, where Cam Meyer and other only dropped out a year before) was (by his admission) that he couldn't get the explosiveness out of the gate to be part of a team which could win Gold. When the gun went, he couldn't even get out of the blocks to catch the wheel of a team led off by Bobridge so he'd have to burn himself just to get to get into 4th wheel.

So I dare say thats the reason he couldn't match the likes of Dennis in the 4km but is proving a talent over longer distances.
 
While the superior aerobic engines of riders are of primary importance in both events, there are still some subtle differences between road TT and track pursuit when you are talking about those last few seconds of performance. Off the top of my head:

- some riders can sustain a higher fraction of their VO2max (pursuit) power at threshold (TT) power, hence relative performance at pursuit and road TT can easily be reversed for two riders with superb aerobic engines.

- the 4km IP requires a much larger contribution from anaerobic work capacity (approximately 25% of the total energy demand give or take) and so while not dominant, it's still a sufficiently large enough contribution to make a difference in performance when you are talking those last few seconds of difference. Every rider has a different contribution from each.

- the opening lap of a pursuit requires an acceleration that can be costly for a larger rider later in the event, and can account for some of the impact on the overall result for some riders compared to others

- aerodynamics can be different between road and track set ups for each rider. What position a rider can sustain for 4-5 minutes might be different to what they can sustain for 40-60 minutes.

- One rides for a different team to the other two so who is to say which has access to better road TT set up or have had access to aero testing facilities? One might have superior road TT equipment/set up but have same equipment access as the others when riding for national/state squads.

- pacing is very important in both events, but is especially crucial in an IP as there is insufficient time to make up for an error, unlike road TTs. Some riders are better at this aspect in shorter events than others (and likewise for longer TTs)

- road TTs often have variable gradients, and so the variable nature of each rider's unique W/kg and W/m^2 profile plays out differently than it does on the track.

- team pursuit at world class level also requires quite decent neuromuscular power.

Any and all of the above could quite easily account for a group of riders with world class aerobic abilities having different relative results in IP vs road ITT.
 
Jan 30, 2011
802
0
0
In addition to what Alex has written, there are 2 other issues that can significantly affect times on the track:

1. ability to stick to the black line
2. gearing

In relation to 1., any drift away from the line costs time. It may be that while Durbo has a track background, his line might not be as good as Hepburn or Dennis. Line on the track can have a significant impact on time; and

In relation to 2., while I would be surprised if this is the case, it may be that Durbo used a lower gearing on the track than Hepburn or Dennis.

These are issues that wouldn't have any carry over to the road.
 
Ferminal said:
Thanks for the reply Alex.

Given they all went through the same track/road program would some of the aero differences be minimal, or does a lot of it just come down to dimensions?
Each rider's morphology and resultant aero (and aero potential) is unique. It requires a lot of investment of time in testing to identify optimal combination of position and equipment that provides the best W/m^2, and that optimal position can be different at the track than on the road partly due to the differences in technical and power demands on the track.

One obvious example of this is width between handlebar extensions. Take this example of Geraint Thomas' bars from the London Olympics and on his road TT bike in Denmark only a few weeks later:





You might be surprised at how little tunnel/aero work is done on riders by AIS/CA. Some riders are constantly changing position anyway (even Durbridge admits this in one of his OGE vids). I have done some aero analysis remotely and privately for one AIS rider who was a world track champion, but had never been near a tunnel, and was never likely to.

Keep in mind that the largest single component in aerodynamics is the rider's morphology and position, so it can easily come down to things like that. But equipment can and does have an influence as well.

Even something like helmet choice - what helmet works best for one rider may not be the best choice for another. But if you're stuck with using the sponsor's kit, well tough. And skin suits - some riders have better suits with better fit - can get 0.5sec/km easily between different suits.

These things all add up and what a rider has available on the track and out on the road can be quite different.
 
Oct 20, 2012
285
0
0
Alex Simmons/RST said:
- road TTs often have variable gradients, and so the variable nature of each rider's unique W/kg and W/m^2 profile plays out differently than it does on the track.
For me this is the main reason plus the fact that road TT taking place outdoors so aerodynamics can be variable and random.
 
Dear Wiggo said:
That motorbike looks close.
Telephoto lens effect.

Dear Wiggo said:
His IP bars look like the ones they use in TP.
They are the TP bars. That was my point, the issues regarding power demand and technical requirements means there will be differences to what set ups you will run for road v track events and those differences will affect different riders differently.
 
Sep 25, 2009
7,527
0
0
alitogata said:
For me this is the main reason plus the fact that road TT taking place outdoors so aerodynamics can be variable and random.
that, in addition to alex's explanations - constancy vs variability

to me, the difference between a 4 and 40 minute racing efforts narrows down to 2 popular metrics used in sports physiology - one's power at vo2 max and one's power at a current anaerobic threshold.

of course it's a simplification, but it helps to put things in a perspective - while AVERAGE power in a 4 km IP would highly correlate (and equal for some) with the individuals power at VO2 max, his/her power in a 40 min road effort would best correlate with a FRACTION of the max vo2 power - specifically, his/her power at an anaerobic threshold (or name it one of the other related term - critical power, power at lt etc).

simply put, regardless of the place a competition is held at (though the differences between the IP and a road prologue are essential), IP is a max STEADY power event and a road ITT is a VARIABLE around threshold power event (up/down, pedaling/coasting at sharp turns...)

to optimize either, different training strategies are required. this is mostly a personal observation backed up by some research.

an lastly, having personal racing experience both in road time trials (i hated mass start r races) and xc skiing in the winter, i found that the demands of winter racing put more stress on my Vo2max than the summer's stress on anaerobic threshold...reconciling the 2 was always a matter to deal with.
 
Jul 17, 2012
5,303
0
0
blackcat said:
track legs require sometime on the boards til you get the suppleness (thats not the word, brain memory work dont).
souplesse "the perfect storm of Looking Pro; harmony between grace and power, casual and deliberate. It speaks of the entire organism, the perfectly manicured machine together with the perfectly refined position and technique of its rider. It is the combination of magnificent Stroke, gentle sway of the shoulders and head, the rhythmic breath, and of knees, elbows, and chest converging on the V-Locus." (velominati guff)

Another good French word like terroir that struggles to find an equivalent in English, and you're right, regular fixed-wheel riding will greatly enhance it
 
May 26, 2010
28,144
2
0
Alex Simmons/RST said:
You might be surprised at how little tunnel/aero work is done on riders by AIS/CA. Some riders are constantly changing position anyway (even Durbridge admits this in one of his OGE vids). I have done some aero analysis remotely and privately for one AIS rider who was a world track champion, but had never been near a tunnel, and was never likely to.

Keep in mind that the largest single component in aerodynamics is the rider's morphology and position, so it can easily come down to things like that. But equipment can and does have an influence as well.

Even something like helmet choice - what helmet works best for one rider may not be the best choice for another. But if you're stuck with using the sponsor's kit, well tough. And skin suits - some riders have better suits with better fit - can get 0.5sec/km easily between different suits.

These things all add up and what a rider has available on the track and out on the road can be quite different.
This is partly why I am so against this stuff. Use a roda bike for TTs in GTs. Makes is fair on everyone. Use the same jersey and shorts as road stages.

Rich teams can afford better gear, testing etc etc
 
Jul 17, 2012
5,303
0
0
Benotti69 said:
This is partly why I am so against this stuff. Use a roda bike for TTs in GTs. Makes is fair on everyone. Use the same jersey and shorts as road stages.

Rich teams can afford better gear, testing etc etc
Then you freeze the sport at a moment in time, like Keirin racing in Japan. The bikes are beautiful but prehistoric.

That said I'd give my right arm for a good 3Rensho or Samson

The commercial side of the sport wouldn't allow that. Technical advances in the professional sport trickle down into the bike you or I can buy in the shops. The professional sport is a shop window for innovation and advance, similar to motor-racing. A level playing field tech-wise is a nice, utopian ideal but is also a luddism. Embrace the tech, we'll have you on elliptical rings yet
 
python said:
IP is a max STEADY power event
After the initial acceleration which is not steady state, yes.

I would say it's the steady state portion of a rider's power trace that is best representative of one's power at VO2max, and not the average power from a pursuit. Provided the effort is well paced.

Even so, power output in a pursuit still varies in a quasi-sinusoidal fashion, how much depend on the rider's preferred method and technique at managing the variability in wheel and crank speed that occurs in transitions between straights and bends.
 
Benotti69 said:
This is partly why I am so against this stuff. Use a roda bike for TTs in GTs. Makes is fair on everyone. Use the same jersey and shorts as road stages.

Rich teams can afford better gear, testing etc etc
All that will happen is a transfer of the same development and testing to road bikes, more aero frame designs, aero mass start helmets, better fitting jerseys, tunnel time to optimise road bike set up for TTs. and so on.
 
Some riders just don't have that natural explosiveness out of the gate. For example Mark Cavendish (who is rather explosive) was under consideration for the IP at the Beijing games and did a test at the Manchester velodrome. His time apparently would of beat out Roulston for the silver medal.
 
Jan 23, 2013
239
0
0
There are four primary classifications of muscle fiber types.

Muscles (as most human cells) can create usable energy in the form of ATP (adenosine triphosphate) via aerobic or anaerobic pathways, or a combination thereof.

Aerobic muscle fibers (classified as oxidative in nature) are better for long endurance efforts (anything lasting more than 10 minutes, or so.

Anaerobic muscle fibers (classified as glycolytic in nature) are better for short bursts of power ranging from 1 second (think high jump) to several minutes (think mile run).

The four primary classifications of muscle fibers are as follows, slow oxidative, fast glycolytic, fast oxidative-glycolytic, and fast oxidative.

A muscle biopsy would reveal the percentage of all fibers that fall into these categories. People who are genetically predisposed to be better at endurance events have a higher concentration of slow-oxidative fibers. Power athletes (jumpers and throwers) have a higher concentration of fast glycolytic fibers.

The ration of these fibers within a certain individual are determined by their genetics and cannot be changed. In other words, an athlete plays with the hand they are dealt.

So, it makes sense that an athlete could excel in an event lasting about four minutes if they have a high concentration of fast oxidative-glycolytic muscle fibers. That same athlete may experience a significant drop in performance for events that last longer.
 
Sep 5, 2009
1,239
0
0
TheBean said:
There are four primary classifications of muscle fiber types.

Muscles (as most human cells) can create usable energy in the form of ATP (adenosine triphosphate) via aerobic or anaerobic pathways, or a combination thereof.

Aerobic muscle fibers (classified as oxidative in nature) are better for long endurance efforts (anything lasting more than 10 minutes, or so.

Anaerobic muscle fibers (classified as glycolytic in nature) are better for short bursts of power ranging from 1 second (think high jump) to several minutes (think mile run).

The four primary classifications of muscle fibers are as follows, slow oxidative, fast glycolytic, fast oxidative-glycolytic, and fast oxidative.

A muscle biopsy would reveal the percentage of all fibers that fall into these categories. People who are genetically predisposed to be better at endurance events have a higher concentration of slow-oxidative fibers. Power athletes (jumpers and throwers) have a higher concentration of fast glycolytic fibers.

The ration of these fibers within a certain individual are determined by their genetics and cannot be changed. In other words, an athlete plays with the hand they are dealt.

So, it makes sense that an athlete could excel in an event lasting about four minutes if they have a high concentration of fast oxidative-glycolytic muscle fibers. That same athlete may experience a significant drop in performance for events that last longer.


The ration (sic) of these fibers within a certain individual are determined by their genetics and cannot be changed. In other words, an athlete plays with the hand they are dealt.

Not according to a study carried out by Dr. Edward F Coyle publishedin 2005 titled "Improved muscular efficiency displayed as Tour de France champion matures" where he hypothecated:


Therefore, one possible mechanism for increased efficiency is that this individual increased his percentage of type I muscle fibers during this 7-yr period of study.

Using our previously reported prediction of the percentage type I muscle fibers from our direct measurements of gross and mechanical efficiency in this individual, we predict that he might have increased his percentage of type I muscle fibers from 60 to 80%.
And surprisingly even with an estimated 20% ratio of FT the subject won some end of stage sprints!

:confused:
 
Mar 18, 2009
2,553
0
0
These two riders have nearly-identical pursuit PBs, both for time and for power (and hence very similar aerodynamic drag)...think they'd be similarly close in a much longer event?

 
Jan 23, 2013
239
0
0
Good point, Velodude.

And, I apologize for my poor typing skills and lack of motivation to proof-read.

There has been much research regarding muscle fiber types, the distribution of those fiber typed within specific muscle groups in an individual, and the effects of training on said distribution.

It is true that the percentage of muscle type - by mass - can and is affected by training. The key point here is "by mass".

Power training will lead to hypertrophic changes in glycolytic muscle fibers, in other words - they get bigger. Therefore, the mass of those fibers increases and they form a greater percentage of the weight of the entire muscle.

However, the total number of muscle fibers of different types remains unchanged - determined by genetics.

According to Wolff's law, the body - and any organ therein - will adapt its structure to respond to the demands of stimuli placed upon it. This is the essence of conditioning and training.

It may seem like we are splitting hairs, here, but it is still important to note than different athletes have genetic predisopsitions to excel in various disciplines.

Track and field (running) is a gret forum for observing this. I find it remarkable than an athlete who excels in the 100m can be marginal in the 200, average in the 400, and completely ineffective at 800m. Similarly, a world class mile runner can be ineffective as a 5k racer.

It is easy to point out the many differences between cycling and running, but it is also interesting to observe similarities. The old adage in Track is that "Sprinters are born and distance runners are made", but that simply isn't true. Distance runners are made with a high concentration of oxidative muscle fibers, narrow hips, a rib cage that allows for larger lung capacity, etc.

I enjoy the physiology-based conversations on this site. It is nice to take a break from reading about doping and scandals and focus on the phenominal physical capacity of pro cyclists and the minor differences in their abilities that lead to exciting racing in various conditions and over various distances.
 

ASK THE COMMUNITY