How much difference does weight loss make in the mountains?

[craig1985]

Jack Bobridge credited his U23 TT win due to losing "5-6kg" after going on a food binge in Australia in July.

 

[Escarabajo]

But most people want an answer to a question like if I weigh 75kg and generate 300W, how much faster up an 8% climb will I be if I drop 7kg. Air resistance needs to be taken into account. Analytic cylcing uses a decent model that factors in a lot of things in. You could, for example, not only reduce the rider's weight but also slightly reduce the frontal area to account for slightly less rider size due to the weight loss.

I have used that too. It is very nice. You can see that when you loose the 7 Kg you don't become a Tour Challenger. I bet you were surprised at the calculations.

 

[Krebs cycle]

a couple of things missing from the discussion so far....

allometric scaling of VO2max is better expressed as ml/kg^0.66 or (ml/kg^0.75) than ml/kg.

smaller athletes have better thermoregulation since body surface area and bodymass are not linearly related ie: for a given % increase in body mass, the % increase in BSA will be much lower, so the ratio of available surface area for heat loss relative to the heat producing internal organs is greater in small people compared to large people.

an interesting study was done at the AIS a few yrs ago that showed the weight loss from dehydration decreases the power required to climb at a given speed in a warm environment (ie: is beneficial for climbing performance), but the detrimental effect of the dehydration more than offset this effect and overall performance was worse.

http://www.ncbi.nlm.nih.gov/pubmed/17277597

so to add to the discussion, weight loss is definately more important for the longer climbs but also it is likely more important during long climbs in WARM-HOT weather.

 

[Race Radio]

Why? Certainly less strength and less peak power but do you have some prove or can you explain the physiological mechanism why someone would lose a significant amount of (mostly aerobically produced that is needed for pursuit) power due to loss of muscle mass?

The answer to your question is pretty obvious and has been addressed a few times on this thread.

Wiggens started with a significant power advantage so while he lost a large amount with his weight loss the fact that he started at such a high level certainly helped.

 

[_frost]

The answer to your question is pretty obvious and has been addressed a few times on this thread.

Wiggens started with a significant power advantage so while he lost a large amount with his weight loss the fact that he started at such a high level certainly helped.

If it is so obvious why don't you point it out to me? I see a few anecdotes of personal experiences and some speculation but no any explanation of the mechanism that would lead to a significant loss of (sustainable) power due to loss of muscle mass?

 

[Race Radio]

If it is so obvious why don't you point it out to me? I see a few anecdotes of personal experiences and some speculation but no any explanation of the mechanism that would lead to a significant loss of (sustainable) power due to loss of muscle mass?

So you see zero correlation between his output over 4 minutes and his output over 30? Most would disagrees with you but you are welcome to your opinions.

Perhaps you can tell us why a loss of 10% of a professional's body weight would not result in a loss of power?

 

[Berzin]

I really wasn't at all impressed by Wiggo's Tour performance.

The Tour profile this year was terrible, and most of the days the peloton raced defensively. So all he had to do was hang on.

Why is this so impressive? He never attacked, and he never rode any of the big guns off his wheel.

Also, there are different types of "thin". Bradley Wiggins looks cadaverous and incredibly pale, like zombie pale. Alberto Contador is thin but he looks tan, fit and very strong.

Wiggo just doesn't look like he will be anything but a wheelsucker because he is not strong enough to attack. He is developing the habit quite a few Tour riders have-ride defensively, try to hold on to whatever placing they have in GC and call it a day when the real attacks come, which have been frequently fewer and farther between as the years go by.

With Astana and now RadioShack in the peloton, their stranglehold on the pace during mountain stages is going to yet again choke the spontaneity out of the race. Now if Wiggins can break that mold and attack balls out, then you can say he's a rider worth spilling ink about as a grand tour contender.

But right now? I don't see anything in his performances that one can say "yes, that was a breakthrough!!!"

Gluten-free my a$$.

 

[Mongol_Waaijer]

exactly.

The commercial aim of the tour was to allow that ******* Armstrong to ride in the elite group without his declining resources being exposed and have an armchair ride to the podium.

This artificially slow pace allowed some surprising names to hang tough with the best riders.

If it was a proper race, on a demanding route, with the better GC riders spread out evenly among more of the teams, and not just a cash in group ride then I'm sure Wiggins would have finished way down.

 

[_frost]

So you see zero correlation between his output over 4 minutes and his output over 30? Most would disagrees with you but you are welcome to your opinions.

There is definately a correlation between power output in 4 and 30 minutes. But change in ratios of those, there may be a correlation or not. Power output in any duration (except very short) can be estimated from critical power (power that one can produce without consuming anaerobic capacity - Maximal Accumulated Oxygen Deficiency) and anaerobic capacity divided by duration. I could easily see a drop in anaerobic capacity due to loss in muscle mass (see eg. http://www.ncbi.nlm.nih.gov/pubmed/8905189?ordinalpos=1&itool=EntrezSystem2.PEntrez.P ubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pu bmed_Discovery_RA&linkpos=2&log$=relatedarticles&l ogdbfrom=pubmed) and that way a drop in power over short durations but the question is what happens to critical power that is dependend on VO2Max (cardiac output, blood oxygen carrying capacity), LT (mitochondrial density and enzymes) and efficiency (ST/FT cell ratio)?

Perhaps you can tell us why a loss of 10% of a professional's body weight would not result in a loss of power?

I cannot. Sorry if you got wrong impression, I am not trying to be a smart a$$ but honestly want to know!

 

[keen_but_slow]

The rate determining step isn't really muscle mass - even at 6Wkg^-1 each fibre is well within its capacity. The limiting step is supplying and processing oxygen, and removing CO2. Clearly, that is only true within limits, at some point there just isn't enough capillary capacity and mitochondria. So yes, you can lose some muscle mass and retain most of your sustainable power. Problem is that the process of losing the mass will reduce the training volume you can cope with so you'll not be able to spend half an hour as close to your VO2max as you did before. Also, you'll be pretty miserable.

Short sharp climbs (like the ones BPC describes) rely on much more than threshold power and so the lower muscle mass can become a factor. His assertion that pros are more affected than amateurs is, of course, total nonsense - if anything they are affected less because they are going faster!

In terms of Wiggins, I was somewhat reassured by the fact that he was dropped on the second day after the second rest day, which from what Bernard Kohl said would indicate that he didn't get as much blood as his peers did. I'd like to think it could have been accumulated fatigue from his first serious attempt at a GT, but then I look at the LAS retic chart and I'm afraid I suspect foul play, which is a disappointment.

 

[Anonymous]

i have to agree with the posters that wiggo's performance is over rated due to the relatively weak parcours.. not saying this proves clean or dirty, but only three mountain top finishes (and andorra neutralised by the wind), and short time trials didn't really give a chance to open up the field, especially given that garmin saved their arses in the TTT compared to lesser teams with more accomplished GC contenders (cervelo, rabo, lotto).. the top ten is usually separated by 25-30 mins, but this time only 14 between first and tenth indicating minimal opportunites to open up the breadth of rider ability.

in addition, in the 3rd week he suffered more than most indicating he is not the 3week specialist that he is made out to be. a tougher parcour in the pyrenees and i reckon wiggo would have felt the effects lasting into the 3rd week and lost a lot more time than he did. a great transformation, but not out of this world as some suggest

 

[cyclingmad]

performance

i have to agree with the posters that wiggo's performance is over rated due to the relatively weak parcours.. not saying this proves clean or dirty, but only three mountain top finishes (and andorra neutralised by the wind), and short time trials didn't really give a chance to open up the field, especially given that garmin saved their arses in the TTT compared to lesser teams with more accomplished GC contenders (cervelo, rabo, lotto).. the top ten is usually separated by 25-30 mins, but this time only 14 between first and tenth indicating minimal opportunites to open up the breadth of rider ability.

in addition, in the 3rd week he suffered more than most indicating he is not the 3week specialist that he is made out to be. a tougher parcour in the pyrenees and i reckon wiggo would have felt the effects lasting into the 3rd week and lost a lot more time than he did. a great transformation, but not out of this world as some suggest

He hasn't focused on or had much experience of grand tours in the past so could improve his 3rd week performances.
Have to agree about the racing not creating the gaps but blame the lack of aggression in racing not the course. I also think smaller gaps between contenders is showing that doping is not having as much impact on performance. All the tours since 2006 have much closer fields and each year it is getting closer

 

[Anonymous]

He hasn't focused on or had much experience of grand tours in the past so could improve his 3rd week performances.
Have to agree about the racing not creating the gaps but blame the lack of aggression in racing not the course. I also think smaller gaps between contenders is showing that doping is not having as much impact on performance. All the tours since 2006 have much closer fields and each year it is getting closer

good point about the racing. maybe a bit of both, in that the top guys didn't want to put their heart on their sleeves in the hill finishes in case they crack and not have another opportunity to make time back (bit like sastre having a go, then got dropped - indicating becoz of the course, riders werent agressive).

i think this all contributed to lesser GT riders being so close to podiums (in terms of minutes and seconds). wiggo will improve for sure, i just think people are saying his performance is out of this world, when given what we both described, its more about a lack of agression from others to dislodge him that, in turn, made him look so good..

i hope he is clean. i like to beleive that the human body can adapt through specialised training and that no-one is a natural GC contender, but rather, they train for it, as wiggo is starting to do

 

[danyela]

This is a very good question. I was discussing this the other day with a friend of mine who is a semi-pro rider. He is roughly the same height and weight as Wiggo after the Olympics - and he is a VERY skinny guy.

We decided it was pretty much impossible for him to lose the same amount of weight, mostly just because he has no extra weight to lose. I know it would have made a huge difference, but I just don't see how he could effectively lose that much weight without losing significant power.

 

[neonpatrick]

The lose in weight will make a very big difference in the mountains. Light weight body person can be easily able to climb on mountain but it become very difficult to heavy weight body. A light weighted body can be easily pulled up.