How much faster would one be if one drop 10 kg?

[RoboLuke]

So there's online calculators and they show some....but not great improvements around a half marathon course.

 

I think the value in loosing weight is that on hills you don't hit lactate threshold so soon....

 

But anyway - I'm asking guys who's managed to drop this amount of weight AT THE SAME FITNESS LEVEL...what % could one expect to be faster over a 50 kim track, say 1,000 meter climbing.

[Ramrod]

I can't give you percentages or figures. I was 112kg at the end of last year. I am now 98kg. What I can tell you is that the difference on climbs is immense. I am also much quicker on the flats. I am roughly the same on the downhills.

[El Dodgius Bastardo]

I can only answer in these terms:

 

If a 70kg rider pushes out 300W of power, an 80kg rider would have to push out an additional 40W of power in order to keep up. Pure power to weight ratio.

 

In real life, you can run a small globe off that. In terms of a distance and time, I can't help you. Maybe some of the smarter people can.

[Ramrod]

Also be prepared to have to buy a complete new wardrobe including cycling kit. not a cheap exercise!

[TheV]

I suppose it has to do with what weight you start off at, it has to be relative to your power to weight ratio if you say fitness "remains the same."

 

For example 10kg's over 70kg's = 14% improvement as opposed to 10kg's/110kg's being 9% improvement into power to weight ratio.

 

If we are talking road racing, and you take average speed of 30km/h over 50'kms then your time = 100min if you improve your power to weight by 10% then you will do about 10min quicker (10%) = 90min race time or 33km/h average speed.

 

In my own experience it's not just the 10kg's that has made the big difference because your fitness never remains the same, you hit the apex where you start losing weight by training more and then your fitness increase also reduces your weight, but from experience I would say if you work to drop 10kg's by actually training harder 70% and eating better 30% of the time then you will see a 10-15% increase in speed/race times over a short period. After that period fitness drives your performance and you will settle into your "natural" weight... I cant explain it any better.. sorry..

 

But the bottom line, if you drop 10kg's you will be MUCH faster dude....

Edited May 31, 2012 by TheV

[El Dodgius Bastardo]

I can only answer in these terms:

 

If a 70kg rider pushes out 300W of power, an 80kg rider would have to push out an additional 40W of power in order to keep up. Pure power to weight ratio.

 

In real life, you can run a small globe off that. In terms of a distance and time, I can't help you. Maybe some of the smarter people can.

 

I neglected the most important part. Are they on the same bikes? We all know that power to weight is irrelevant when riding different wheel sizes

[Icycling]

I recently (over 14 months - still aiming for 75kg by Nov - same weight as what I left school at) dropped 15 kg from like 93 kg to 78 kg - huge diffrence. So now at almost 40 years of age just 3 week ago I could win an elite CAT 1 race in WP - making it a bit more impressive was that Darren Lill was 2nd not to mention 3rd and 4 th sport were top riders from the WP who are / have raced overseas in the past year. The race was a crit with 4 tight corners - so acceleration was important out of the corners - weight makes a huge difference their too.

 

I also now train on route with climbs instead of looking for flatter ride - climbing is so much more fun!

 

I would say I have always been quite fir having done 29 Cycle tours of which 20 in under 3hrs and 3 in under 2h30!

[El Dodgius Bastardo]

That's exactly where power to weight comes into play, acceleration and climbing. Downhills are for fat bastiches like me.

[rudi-h]

The following table shows the power required to ride a 4% hill at a speed of 18km/hr. The first table is for a 90kg person, and the second is for a 80kg person.

 

The difference is roughly 20W or 10%.

 

 

 

Obviously there's wind drag and rolling resistance, but on a steep hill this is the improvement that you're looking at.

 

90kg dude

 

Gradient 4%

Rider mass 90 kg

Bike mass 10 kg

Cycling speed 18 km/hr

Vertical speed 0.200 m/s

Power 196.2 W

 

80kg dude

 

 

Gradient 4%

Rider mass 80 kg

Bike mass 10 kg

Cycling speed 18 km/hr

Vertical speed 0.200 m/s

Power 176.6 W

 

It will also mean that if you would pedal at the same power output, you can go 2 km/hr faster on the same hill if you're 10 kg lighter. This would mean about a 40 second difference on a 2km long hill.

 

Gradient 4%

Rider mass 80 kg

Bike mass 10 kg

Cycling speed 20 km/hr

Vertical speed 0.222 m/s

Power 196.2 W

Edited May 31, 2012 by rudi-h

[El Dodgius Bastardo]

Power meters will make geeks out of the lot of us

[Icycling]

That was fit not fir!

 

Don't believe in power meters - I have not even used a Heart rate monitor since about 1994

 

Analysis leads to Paralysis!

[TheV]

I recently (over 14 months - still aiming for 75kg by Nov - same weight as what I left school at) dropped 15 kg from like 93 kg to 78 kg - huge diffrence. So now at almost 40 years of age just 3 week ago I could win an elite CAT 1 race in WP - making it a bit more impressive was that Darren Lill was 2nd not to mention 3rd and 4 th sport were top riders from the WP who are / have raced overseas in the past year. The race was a crit with 4 tight corners - so acceleration was important out of the corners - weight makes a huge difference their too.

 

I also now train on route with climbs instead of looking for flatter ride - climbing is so much more fun!

 

I would say I have always been quite fir having done 29 Cycle tours of which 20 in under 3hrs and 3 in under 2h30!

 

KEEP AT IT!! WELL DONE

 

Plus, remember we are all just human, your name and experience only takes you so far, it's the training that pays off at the end of the day!!!

[patches]

The artist formerly known as BigBen should also give some input here!

 

I barely recognized him last week! He was fast before... would be interesting to hear his take on it now that he's shed a few.

[shaper]

I started cycling again last August as had ballooned to 95kgs, I got down to 75kgs in 6 months and now am happy at the weight.

 

Can agree that hills are much more fun and actually prefer to downhill lol

 

So can vouch that it makes a big difference ..

[Zac.A]

That was fit not fir!

 

Don't believe in power meters - I have not even used a Heart rate monitor since about 1994

 

Analysis leads to Paralysis!

 

What is measured improves, maybe there's room for more?

[Cav']

I recently (over 14 months - still aiming for 75kg by Nov - same weight as what I left school at) dropped 15 kg from like 93 kg to 78 kg - huge diffrence. So now at almost 40 years of age just 3 week ago I could win an elite CAT 1 race in WP - making it a bit more impressive was that Darren Lill was 2nd not to mention 3rd and 4 th sport were top riders from the WP who are / have raced overseas in the past year. The race was a crit with 4 tight corners - so acceleration was important out of the corners - weight makes a huge difference their too.

 

I also now train on route with climbs instead of looking for flatter ride - climbing is so much more fun!

 

I would say I have always been quite fir having done 29 Cycle tours of which 20 in under 3hrs and 3 in under 2h30!

So you did your first Cycle tour at 11 years old and haven't missed one in 29 years.....Are you a robot