Does 20% loss in body weight = 20% better time climbing?

[Indurain]

I did a timetrial under race conditions up this 2km climb that averages about 7 or 8%. I did it in 7mins 05secs. I did it when I was 103kg's on a 7kg bike with wheels weighing 1.65kgs (without skewers and tyres). I only had my training tyres on (Gatorskins I think).

My Goal for next year is to drop about 20kg's. I am hoping I can do this same climb in under 6mins. If I drop 20% weight, will this translate into a 20% better time (5mins 40secs) given that if I am riding at the same speed as someone that is 80kg's up that climb I am generating 20% more power to keep up if all other factors are the same.

Will cutting this weight also provide any benefits in sprinting or timetrialling, how much would you expect?

Thanks in advance.

 

[the student]

I wouldnt expect the full 20% as a factor of weight loss only... to loose weight in the first place you will probably ride a lot... so that makes for more training. More training usually makes you faster by most not the weight loss itself.

The weight loss will help you accellerate more easily in sprints ... or more important getting up to speed again after corners.

so the weight loss will make you climb more easily ... but the training you will do to get the weight loss will make the biggest difference... so doing both might make the full 20%

 

[redtreviso]

Losing 20% will give you better than 20% chance of not blowing a gasket compared to climbing at your present weight.

 

[scribe]

There is a factor of loss of energy with the drop in weight. But that is strictly individual and should be carefully considered. For example, Boonen can't transform himself into a Schleck if he wanted to. Two entirely different animals..

 

[on3m@n@rmy]

Agree with previous poster replies. Another way to think of it is FORCE = MASS * ACCELERATION. Force required on the pedals to maintain speed is a direct relationship to your mass. So if you cut your mass by 20%, you will require 20% less force to keep up, you will not burn out as quickly, and the climbs will seem easier. But to go one step further...
TIME = SQRT(2*D*M/FORCE) where D=Distance, M=mass.
So for the same force applied over a given distance and at 20% less mass your time is about 10% quicker... all because of the square function.

 

[Squares]

I did a timetrial under race conditions up this 2km climb that averages about 7 or 8%. I did it in 7mins 05secs. I did it when I was 103kg's on a 7kg bike with wheels weighing 1.65kgs (without skewers and tyres). I only had my training tyres on (Gatorskins I think).

My Goal for next year is to drop about 20kg's. I am hoping I can do this same climb in under 6mins. If I drop 20% weight, will this translate into a 20% better time (5mins 40secs) given that if I am riding at the same speed as someone that is 80kg's up that climb I am generating 20% more power to keep up if all other factors are the same.

Will cutting this weight also provide any benefits in sprinting or timetrialling, how much would you expect?

Thanks in advance.

The key to climbing is the weight to power ratio. A 100 kg rider must put out 25% more power to climb a given hill as the same rate as an 80 kg rider.

So, if you lose 20 kg, and don't lose any power you will gain more than a 20% improvement! Good luck on the weight loss.

 

[Clearly Unstable]

This thing is fun to play with...

http://www.exploratorium.edu/cycling/aerodynamics1.html

 

[hfer07]

20% less mass will definitely help & improve your climbing-but it does not equals 20% gains in speed-the mayor benefit you'll notice is to maintain a faster phase longer than you have with your previous weight. also is going to give you more comfort to get out of the saddle & your knee caps/joints are going to feel less pressure. about the speed-yes-you'll gain some but not that kind of percentage unless you use PED last keep in mind that sometimes during weight loss your strength can suffer if you do it too fast. good luck

 

[tifosa]

Your equation may not become your performance reality unless you couple dieting with weigh-bearing workouts: soccer, walking, basketball, tennis, and the like. You want to lose fat and not muscle mass. Cycling, while great exercise, won't help you drop the weight efficiently.

A healthy equation looks like this:

Diet (low fat + low-glycemic carbs + high protein) + Exercise (50% weight-bearing + 50% cycling) + 10-12 weeks time (you're a bloke, right?) = -20kg

This will let you sustain the weight loss.

Good luck!

 

[Oldman]

There is a factor of loss of energy with the drop in weight. But that is strictly individual and should be carefully considered. For example, Boonen can't transform himself into a Schleck if he wanted to. Two entirely different animals..

+1: this ambitious level of weight transformation will have other impacts. You will need to change diet/caloric intake while training excessively and may find yourself actually slower if you proceed too quickly; particularly when increasing training mileage dramatically. Most serious competitors would consider this a longer range goal based on the ability to train and recover. You would want to monitor that closely to not sacrifice any power in the process.
Also this consideration: if you think you sprint well now you may say goodbye to that attribute. Scribe is correct and that's why Boonen isn't really interested in looking like Schleck.

 

[Black-Balled]

I definitely suggest you use both skewers and tires next time.

 

[Indurain]

Very Funny Black-Balled

Hey guys, I have 20kg's to lose in abt 11mths. That's like 1/2kg a week. Last year I dropped from 122kgs to 96kg's at my lowest and felt fine a few days after I ate normally. Power wise it doesn't seem to have effected me. For the last 3mths, I've been a junk food addict and actually started gaining weight while riding abt 350km's a week (pretty incredible, I know, got to 105kg's). Now 101kg's.

I am finding if I cut out the crap and just eat normally the weight is coming off quite naturally. I do feel a bit weaker at times if I eat too little but I try and make these on my recovery days and eat a bit more the night before when I know I have interval training coming up. I noticed recovery may take a little longer than normal.

My idea is during the off season and my initial endurance base training, I will try and lose big chunks of weight through heavier dieting. Then I will increase my intake of calories, etc as the intensity goes up. Shouldn't lose too much muscle hopefully. This way I will slow down the loss to a pound a week instead, thereafter. Hoping no long term effects on my season.

Mixed messages re: the relationship between % mass lost vs % time I improve for a given climb. but given I'll be eating healthier and will be lighter, it's sure to be a huge improvement on now. Thanks for the replies.

 

[eljimberino]

Once you lose the weight, you start again with the energy levels. It's not like everyone out there who is 20kgs lighter than you is worried about being 20% weaker.

 

[Tim_sleepless]

My Goal for next year is to drop about 20kg's. I am hoping I can do this same climb in under 6mins. If I drop 20% weight, will this translate into a 20% better time (5mins 40secs) given that if I am riding at the same speed as someone that is 80kg's up that climb I am generating 20% more power to keep up if all other factors are the same.

Not quite, as some of your power even at 7% incline is still being used to overcome air resistance (how much will obviously also change if your frontal area diminishes, rather than just your gut).

Try playing around here.


http://www.analyticcycling.com/ForcesSpeed_Page.html

 

[Altitude]

That's a lot of weight to lose. Unless it's all fat you'll probably do more harm than good.

 

[Indurain]

Trust me when I say it's all fat. My race weight when I was 20 use to be 74kg's and that was working a hard labour job full time and cycling. S0, added muscle over the years probably wouldn't be too significant, I'd think. When I get there, I'll repost and give you the % time difference at 10 and 20kg's lost. Could be interesting.

 

[Irish2009]

Losing 20% of your body weight will not cause a 20% increase in performance. It will affect your power to weight ratio and the percentage difference in this ratio will be your improvement. You will notice a dramatic improvement in your ability for every 5% of weight you lose, if you maintain your power output. If you have a large amount of fat to lose the initall improvements will be great, as you get fitter and lighter the incrments of improvement will get smaller.

 

[straydog]

Your equation may not become your performance reality unless you couple dieting with weigh-bearing workouts: soccer, walking, basketball, tennis, and the like. You want to lose fat and not muscle mass. Cycling, while great exercise, won't help you drop the weight efficiently.

A healthy equation looks like this:

Diet (low fat + low-glycemic carbs + high protein) + Exercise (50% weight-bearing + 50% cycling) + 10-12 weeks time (you're a bloke, right?) = -20kg

This will let you sustain the weight loss.

Good luck!

Ok to the OP. The short answer is that yes, of course losing 20kgs from your present weight will help your climbing. I would go so far as to say that carrying unnecessary weight is the biggest limiter for recreational cyclists. As has been mentioned a few times above, your watts/weight ratio is the most important factor, so as long as the weight you lose is fat and not lean muscle mass you will definitely notice a huge difference if you lose 20 kgs, and I say this from experience.

The reason I quote Tifosa is because I take issue with what she has said. In terms of cycling specific strength, the only important exercise is , well, er cycling. Running, swimming, gym workouts etc. can build muscle (and therefore weight) that will actually hinder improvement as a cyclist and certainly won't positiviely impact on it. Maintaining a healthy lifestyle is of course to be recommended, so play whatever sports you want outside of bike riding, but don't expect them to help your cycling in any way, other than possibly improving your cardio vacular efficiency slightly. Also I would argue that cycling is a very efficient , although time consuming, way of losing weight, as long as you combine it with sensible modifications to your diet.

I will use myself as an example; I am 6 ft 3 and have been as high as 92 kilos three winters ago when I was competing at olympic distance triathlon. My upper body particularly bulked up from all the swimming. This impacted my climbing hugely. Despite being a quick time trialller on the flat, whenever the road went up, I went backwards. Quickly. Embarrasingly.

Firstly I started competing at long distance triathlon and did less anaerobic swimming drills and more long distance cycling and running, and I got down to 79 for races. My upper body got less cut and bulky, and my climbing improved a bit, but I still didn't really enjoy it.

This year I haven't swum or run at all. I have only been cycling. Admittedly alot, which has obviously helped with further weight loss. I now hover between 71 and 73 and I genuinely can eat what I want. And this summer in france my climbing has gone through the roof. I love it. So much so that I actually find it incredibly boring doing a long ride that doesn't have some serious hills on it. The downside is I now have the chest of a ten year old boy, although I am oddly proud of it

One thing i do agree with Tifosa on is diet. Low Glycaemic carbs. Cut processed sugars right down and up your protein intake.

Good luck. A kilo to two kilos a month is perfectly achieveable if you are disciplined and have the time to ride alot. Take your time and be sensible.

 

[tubularglue]

losing 20% of body weight is quite monumental.

little by slowly


just a thought

 

[Indurain]

Thanks for the tips. Time to show the guys that this Fat Man has life in him yet. They'll think I'm on the juice.

 

[Sasquatch]

You want to lose it healthily?

Use these two products in conjunction with each other.

http://www.mrsupplement.com.au/australia/powerzone-nutrition-hgh-formulation.html

http://www.mrsupplement.com.au/australia/maxs-hydroxyphase.html

You will drop the fat, and put on lean muscle mass. You could end up at 75 and still keep the muscle.

 

[CoachFergie]

http://bikecalculator.com/

Will allow you to compare where you are now to where you plan to be. I have a similar amount to lose myself, best wishes!

 

[Indurain]

Using a few of the sites suggested by you guys, I put in all of the appropriate data and came up with an 18.6% improvement on time for a loss of 23kg's for the 2km climb, 6.5% avg gradient.

This is of course quite significant. The steeper it gets, the greater the improvement. Thanks for all your help.

 

[tifosa]

Straydog, the reason I suggested an even mix of cycling AND weight bearing exercise is not to increase size, but rather, not to lose muscle mass. It's not forsaking cycling, it's a means to more quickly, and safely reach your goal of losing fat while keeping your strength.

While you may have "bulked up" from swimming, swimming is not a weight bearing exercise. And while you will certainly tone and increase your upper body mass, and you may lose weight (not necessarily all fat), it is not the most effective way to increase the efficiency of your engine. That's where weight bearing exercise comes in; it helps you burn fuel (fat), but not at the expense of muscle. At least that's been my experience.

 

[Polyarmour]

Straydog, the reason I suggested an even mix of cycling AND weight bearing exercise is not to increase size, but rather, not to lose muscle mass. It's not forsaking cycling, it's a means to more quickly, and safely reach your goal of losing fat while keeping your strength.

While you may have "bulked up" from swimming, swimming is not a weight bearing exercise. And while you will certainly tone and increase your upper body mass, and you may lose weight (not necessarily all fat), it is not the most effective way to increase the efficiency of your engine. That's where weight bearing exercise comes in; it helps you burn fuel (fat), but not at the expense of muscle. At least that's been my experience.

I think riding a bike is the best way to lose weight and here is why.

I can ride a bike burning 500 - 700 Cals/hr for (let's say) 4 hours and I can do it day after day without a problem.
OR
I can run burning 500 -700 Cals/hr for about 30-45 minutes. Anything beyond that and my legs, knees and ankles will have problems and I probably need a day's break here and there to stop injuries from accumulating.
OR
I can walk burning 250 Cals/hr for 4 hours, can do it daily but have to watch for blisters.
OR
I can swim at about 300 Cals/hr for 1 hr before I'm totally bored out of my brain.

In terms of total energy consumption, the bike wins hands down.