# Is there a correlation between weight loss and power gain?



## arkitect (Apr 25, 2011)

This may be a really dumb question but you don't know me so I will ask it and you can make fun of me. 
I am a road racer and i am going to drop some weight over the winter. Essentially I am going to cut calories a bit and also stop lifting weights for my upper body. I have at least 10-15 lbs of chest, back and arm muscle weight. 

Anyways, I was wondering if there is going to be an increase ( however slight) with the associated weight loss? In other words, if my FTP is 300 watts, is there an associated wattage gain for every pound I lose? I am not losing the weight to get a power increase but am curious if there is a correlation with doing so. 

Thanka


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## Local Hero (Jul 8, 2010)

All else being equal, your FTP will stay the same. With weight loss, you may get a better power to weight ratio. 


That said, the right training plan will cause an increase in power and loss of excess weight. I wont get into what it takes to burn off muscle, losing muscle vs fat, et cetera. Maybe someone else can elaborate on that.

To answer your question plainly: *No.* Losing weight will not--by itself--cause an increase in power. It will feel like you have more power though, as you'll be accelerating less mass.

EDIT: 

Arkitect: Have you had your body fat percentage tested? 

I don't know your BF% but I am willing to guess that you could lose 10lbs of excess weight (fat) without losing much muscle.


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## Used2Run (Sep 5, 2012)

*Exercise Physiology*

Losing EXTRA mass above your optimal size will make you faster. It's simple physics. Less weight to carry over a distance will equal less effort to maintain the same pace over the same distance. The problem will be figuring out when to stop cutting weight. If you go below your optimal weight, your performance will suffer, you could become anemic, over train, and do fun things like those. If you start to feel run down, tired, or sick, stop losing weight!


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## looigi (Nov 24, 2010)

Keep training on the bike and get enough high quality protein for recovery. You want your upper body to atrophy, but not your legs, otherwise you'll lose leg power. 

IMO, it's a difficult and delicate balance to lose weight and still fuel properly for productive training.


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## spade2you (May 12, 2009)

Sometimes. It's possible to gain weight and lose power, lose weight and lose power, gain weight and gain power, and lose weight and gain power.


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## Ventruck (Mar 9, 2009)

No correlation in those terms specifically. In a test bed of same average speed and course, you actually put out more power with more mass because the body has to do more work in the same given time.

Less weight_ could _in general make you faster. Whether you get wattage gains is due to starting fitness level. You could be losing or gaining needed strength.


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## TehYoyo (Sep 16, 2012)

I can't imagine how losing weight would make your legs stronger. But if you're wondering about _going_ faster, then you'll definitely go faster - simple physics. The less weight you have to push, the faster you'll go w/ the same power.


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## bocksta (Mar 22, 2008)

Without question you will be climbing and riding faster, but only if your losing the fat not the muscle. I use a scale with body fat readings to keep track of my lean body mass while dropping weight. When i notice my percentage of lean body weight drop i up the carbs for a few days . 
You could easily lose 2-3 lbs a month by just watching the scale daily.


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## Local Hero (Jul 8, 2010)

On the other hand, I wonder who would win:

a) 185lb rider with a FTP of 200 riding a 15lb bike

b) 135lb rider with a FTP of 200 riding a 65lb bike

(all other variables are the same) 

Both riders use 200 watts to propel 200lbs. On paper it is a tie. But somehow we know the heavier rider is doing more work. At least I tend to think that the heavier guy is sweating more. It will take more out of him. 


Our flesh is not a dead weight. Flesh burns oxygen, even if it is not directly used in the exercise. The majority of our energy is dissipated as heat and heavy muscles get hot faster. So the heavier guy is going to need to fuel more muscles and sweat more for an equivalent performance. 

Carrying, fueling and cooling extra muscle on the body is more difficult than carrying the same amount in dead weight.

*So I am starting to think that without the extra muscles on the rider, more resources will be "freed up" for the legs, thus raising the FTP. *


My opinion is not settled on this. I'm just thinking out loud. I would love to be corrected here.


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## InfiniteLoop (Mar 20, 2010)

Local Hero said:


> On the other hand, I wonder who would win:


There's more to it, but in simplistic terms the heavier of your two riders will have the advantage because he can use his extra body weight to propel the pedals, the lighter rider just has dead weight he's trying to propel. Other factors will play a role though. The heavier rider is live weight moving around that will require some xtra energy to counteract (unless he can achieve absolute perfect motion) and his extra organ/muscle/blood mass will require a bit more energy simply to exist each minute of riding, much less to put forth effort. In the end, if you told me that every pound I lost would be attached to my bike as extra weight, I think I'd keep the weight on my body.


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## Local Hero (Jul 8, 2010)

InfiniteLoop said:


> There's more to it, but in simplistic terms the heavier of your two riders will have the advantage because he can use his extra body weight to propel the pedals, the lighter rider just has dead weight he's trying to propel. Other factors will play a role though. The heavier rider is live weight moving around that will require some xtra energy to counteract (unless he can achieve absolute perfect motion) and his extra organ/muscle/blood mass will require a bit more energy simply to exist each minute of riding, much less to put forth effort. In the end, if you told me that every pound I lost would be attached to my bike as extra weight, I think I'd keep the weight on my body.


I like the way you think. Now let's rearrange the thought experiment. 

Take those 50lbs off the bike and put it on a weight vest. Make the weight vest breathable, so heat doesn't build up (as it does under a backpack).


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## rockdude (Apr 3, 2008)

Local Hero said:


> *So I am starting to think that without the extra muscles on the rider, more resources will be "freed up" for the legs, thus raising the FTP. *


Bing, Bing, Bing, We have a winner.


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## Local Hero (Jul 8, 2010)

Just imagine if his blood volume stays the same but he has 10% less muscle/fat to feed.


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## arkitect (Apr 25, 2011)

Local Hero said:


> EDIT:
> 
> Arkitect: Have you had your body fat percentage tested?
> 
> I don't know your BF% but I am willing to guess that you could lose 10lbs of excess weight (fat) without losing much muscle.


Yes, most recently i was at 9% (caliper testing, not real accurate I am sure). Would like to have it done by the underwater method though.


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## scottzj (Oct 4, 2010)

I too am looking for a major transformation during the winter training season. I would like to lean down to 165-170 at 6'3. However, I have been told that this could be "too lean" and I could loose power. My teammates call me the diesel, as my power and strength to hold speeds for a long time is pretty good. So I dont want to loose that, but in turn want to drop more pounds in hopes to give me better fast twitch muscles and less weight to tow around.


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## Ventruck (Mar 9, 2009)

scottzj said:


> I too am looking for a major transformation during the winter training season. I would like to lean down to 165-170 at 6'3. However, I have been told that this could be "too lean" and I could loose power. My teammates call me the diesel, as my power and strength to hold speeds for a long time is pretty good. So I dont want to loose that, but in turn want to drop more pounds in hopes to give me better fast twitch muscles and less weight to tow around.


That lower limit of weight is ultimately dictated by genetics.Some people at that height have lower bone density for whatever reason. I recall a 6+ ft guy posting here about being stuck at 125lb.

You could try losing the weight to see what happens. You can't really predict the outcome, but only train ideally towards it.


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## JCavilia (Sep 12, 2005)

*Physics*



Used2Run said:


> Losing EXTRA mass above your optimal size will make you faster. It's simple physics. Less weight to carry over a distance will equal less effort to maintain the same pace over the same distance. The problem will be figuring out when to stop cutting weight. If you go below your optimal weight, your performance will suffer, you could become anemic, over train, and do fun things like those. If you start to feel run down, tired, or sick, stop losing weight!





> I can't imagine how losing weight would make your legs stronger. But if you're wondering about going faster, then you'll definitely go faster - simple physics. The less weight you have to push, the faster you'll go w/ the same power.



Both of you guys don't have this quite right. It doesn't take any more energy to keep a larger mass moving than a smaller one. It does take more energy to ACCELERATE a larger mass, or to LIFT it. So in practice, the lighter rider will go faster on the average ride, because there's some uphill, and there is some acceleration out of turns, etc. But comparing 2 riders at a steady speed on flat ground, if drag and other factors are equal, it will not take more power to keep the more massive rider going. You only have to "push" weight when you're climbing or accelerating. At a steady speed on the flat, your work is overcoming air drag, which is related to size (volume, frontal area), but not directly related to mass. A lot of the great time-trialists are on the bigger side.


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## King Arthur (Nov 13, 2009)

arkitect said:


> This may be a really dumb question but you don't know me so I will ask it and you can make fun of me.
> I am a road racer and i am going to drop some weight over the winter. Essentially I am going to cut calories a bit and also stop lifting weights for my upper body. I have at least 10-15 lbs of chest, back and arm muscle weight.
> 
> Anyways, I was wondering if there is going to be an increase ( however slight) with the associated weight loss? In other words, if my FTP is 300 watts, is there an associated wattage gain for every pound I lose? I am not losing the weight to get a power increase but am curious if there is a correlation with doing so.
> ...


There will be a gain in power to weight ratio, (translated roughly : more power to get up and over those hills.) Whether or not you gain in the FTP department, depends on if you train or live in an area where the terrain is rolling or mountainous. If the area is flat, perhaps not so much, but this is where interval training makes up the difference.


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## Kerry Irons (Feb 25, 2002)

*Not quite right*



JCavilia said:


> Both of you guys don't have this quite right. It doesn't take any more energy to keep a larger mass moving than a smaller one. It does take more energy to ACCELERATE a larger mass, or to LIFT it. So in practice, the lighter rider will go faster on the average ride, because there's some uphill, and there is some acceleration out of turns, etc. But comparing 2 riders at a steady speed on flat ground, if drag and other factors are equal, it will not take more power to keep the more massive rider going. You only have to "push" weight when you're climbing or accelerating. At a steady speed on the flat, your work is overcoming air drag, which is related to size (volume, frontal area), but not directly related to mass. A lot of the great time-trialists are on the bigger side.


In practice on a bicycle more weight means more rolling resistance. The tires flex more and this means hysterisis losses. Maybe a tiny bit more bearing drag as well. Not a big number but more weight pays penalties in many ways. Of course it must be stated that 1 lb. added weight on the flats results in all of a 0.01 mph speed increase. That's 15 seconds every 100 miles


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## arkitect (Apr 25, 2011)

King Arthur said:


> There will be a gain in power to weight ratio, (translated roughly : more power to get up and over those hills.) Whether or not you gain in the FTP department, depends on if you train or live in an area where the terrain is rolling or mountainous. If the area is flat, perhaps not so much, but this is where interval training makes up the difference.


This makes a lot of sense. Thinking about it some more, it makes sense that my FTP would not increase but since i live in Colorado, my climbing should improve somewhat with less weight. Lots of interesting discussion on this topic, so thanks for everyone that posted.

My intense training for next season doesn't really start until January, now until then I am still training and about ready to do some leg lifting so cutting calories now is great timing. I will never be a Schleck brother but I would like to only have muscle where I really need it, and can make use of it for cycling.


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## JasonLopez (Aug 19, 2012)

Whatever you do, do it in a healthy manner and watch your body. Nothing drastic. Slow and steady changes.

Stay healthy my friend.


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